Infectious Flashcards
(315 cards)
1
Q
What is the most specific early clinical sign of measles?
A) Conjunctivitis
B) Rash
C) Fever
D) Koplik spots
E) Lymphadenopathy
A
Answer: D
Explanation: Koplik spots are pathognomonic for measles and appear 1–2 days before the rash.
2
Q
The measles virus belongs to which family?
A) Picornaviridae
B) Herpesviridae
C) Flaviviridae
D) Paramyxoviridae
E) Retroviridae
A
Answer: D
Explanation: Measles is caused by a single-stranded RNA virus from the Paramyxoviridae family.
3
Q
How is measles primarily transmitted?
A) Blood transfusion
B) Feco-oral route
C) Airborne droplets
D) Direct contact with saliva
E) Insect vectors
A
Answer: C
Explanation: Measles spreads through airborne respiratory droplets, making it highly contagious.
4
Q
What is the typical pattern of measles rash?
A) Starts from limbs to trunk
B) Generalized vesicular eruption
C) Begins behind ears and spreads downward
D) Confined to lower limbs
E) Petechial in nature
A
Answer: C
Explanation: The rash starts on the face (behind ears) and spreads cephalocaudally to trunk and limbs.
5
Q
What is the incubation period of measles?
A) 2–5 days
B) 7–10 days
C) 10–14 days
D) 1–2 days
E) 3 weeks
A
Answer: C
Explanation: The typical incubation period is around 10–14 days before symptom onset.
6
Q
What is the most common cause of death in measles?
A) Encephalitis
B) Pneumonia
C) Diarrhea
D) Dehydration
E) Otitis media
A
Answer: B
Explanation: Pneumonia is the leading cause of mortality in measles, particularly in malnourished children.
7
Q
Which vitamin supplementation is recommended in measles?
A) Vitamin D
B) Vitamin C
C) Vitamin A
D) Vitamin B12
E) Folic acid
A
Answer: C
Explanation: Vitamin A reduces morbidity and mortality, especially in children <2 years.
8
Q
Which of the following is a complication of measles?
A) Guillain-Barré syndrome
B) Subacute sclerosing panencephalitis (SSPE)
C) Aseptic meningitis
D) Reye’s syndrome
E) Hemolytic anemia
A
Answer: B
Explanation: SSPE is a late, rare, fatal neurological complication of measles.
9
Q
Which cells are targeted for initial replication of measles virus?
A) Neurons
B) Epithelial cells of skin
C) Dendritic and macrophage cells
D) Hepatocytes
E) Muscle cells
A
Answer: C
Explanation: Measles replicates first in respiratory dendritic and mononuclear cells, then spreads systemically.
10
Q
When is a patient with measles most infectious?
A) During rash only
B) After rash resolves
C) 4 days before and 4 days after rash
D) Only when fever is present
E) Only during incubation period
A
Answer: C
Explanation: Measles is highly contagious from 4 days before to 4 days after the rash.
11
Q
What is the diagnostic method of choice in early measles?
A) Throat culture
B) Anti-measles IgM
C) Skin biopsy
D) PCR of stool
E) ELISA for IgG
A
Answer: B
Explanation: Measles-specific IgM appears within a few days of rash and confirms acute infection.
12
Q
Which of the following is a hallmark of measles-associated diarrhea?
A) Blood and mucus
B) Chronicity
C) Association with lactose intolerance
D) High volume, watery diarrhea
E) Steatorrhea
A
Answer: D
Explanation: Measles can cause watery diarrhea due to enterocyte infection and mucosal damage.
13
Q
What is the most common otologic complication of measles?
A) Sensorineural hearing loss
B) Otitis media
C) Mastoiditis
D) Tympanic membrane rupture
E) Tinnitus
A
Answer: B
Explanation: Otitis media is the most common complication, especially in young children.
14
Q
At what age is the first dose of MMR vaccine given in routine immunization?
A) At birth
B) 6 weeks
C) 9 months
D) 12–15 months
E) 6 months
A
Answer: D
Explanation: In many immunization programs, MMR is given at 12–15 months, but in endemic settings it may be given at 9 months with repeat later.
15
Q
What is the role of isolation in measles?
A) Until cough resolves
B) Until rash fades
C) 4 days after rash onset
D) 2 weeks after fever
E) Until stool is normal
A
Answer: C
Explanation: Isolation is required for 4 days after rash onset, as the child remains infectious.
16
Q
What is the most common presentation of mumps in children?
A) Fever and rash
B) Parotitis
C) Orchitis
D) Meningitis
E) Conjunctivitis
A
Answer: B
Explanation: Mumps classically presents with painful swelling of the parotid gland, usually bilateral.
17
Q
Mumps virus belongs to which virus family?
A) Herpesviridae
B) Flaviviridae
C) Orthomyxoviridae
D) Paramyxoviridae
E) Adenoviridae
A
Answer: D
Explanation: Mumps is caused by an RNA virus of the Paramyxoviridae family.
18
Q
What is the incubation period for mumps?
A) 2–5 days
B) 5–9 days
C) 10–14 days
D) 14–18 days
E) 21–28 days
A
Answer: D
Explanation: Mumps has an incubation period of 2–3 weeks, most commonly 14–18 days.
19
Q
The most common complication of mumps in post-pubertal males is:
A) Infertility
B) Orchitis
C) Epididymitis
D) Urethritis
E) Testicular torsion
A
Answer: B
Explanation: Mumps orchitis occurs in about 20–30% of post-pubertal males and may affect fertility.
20
Q
Which of the following is NOT a known complication of mumps?
A) Meningitis
B) Pancreatitis
C) Sensorineural hearing loss
D) Myocarditis
E) Hemolytic anemia
A
Answer: E
Explanation: Hemolytic anemia is not a typical complication. Mumps can cause meningitis, encephalitis, pancreatitis, and hearing loss.
21
Q
The MMR vaccine provides protection against:
A) Measles, Malaria, Rubella
B) Mumps, Measles, Rotavirus
C) Measles, Mumps, Rubella
D) Meningitis, Mumps, Rubella
E) Measles, Malaria, RSV
A
Answer: C
Explanation: MMR vaccine covers Measles, Mumps, and Rubella.
22
Q
When is a patient with mumps most contagious?
A) After onset of rash
B) During fever only
C) 1 day after parotitis
D) 2 days before to 5 days after parotitis
E) Only in symptomatic phase
A
Answer: D
Explanation: Mumps is most contagious 2 days before to 5 days after onset of parotid swelling.
23
Q
A child with painful bilateral parotid swelling and elevated serum amylase likely has:
A) Parotitis
B) Acute pancreatitis
C) Submandibular sialadenitis
D) Sjögren syndrome
E) Mumps
A
Answer: E
Explanation: Elevated serum amylase in a child with parotid swelling suggests mumps parotitis.
24
Q
What is the typical CSF finding in mumps meningitis?
A) High neutrophils
B) Low protein
C) Normal glucose
D) Very low glucose
E) Positive gram stain
A
Answer: C
Explanation: Mumps meningitis is viral, so CSF shows lymphocytosis, normal glucose, and slightly elevated protein.
25
Which salivary gland is most commonly affected in mumps?
A) Submandibular
B) Sublingual
C) Parotid
D) Buccal
E) Minor accessory glands
Answer: C
Explanation: Parotid gland is most frequently involved in mumps, often bilaterally.
26
What is the best method to confirm mumps diagnosis?
A) ESR
B) PCR from saliva
C) ELISA for IgG
D) WBC count
E) Throat culture
Answer: B
Explanation: RT-PCR from saliva or buccal swab is sensitive and specific for mumps diagnosis.
27
Mumps-associated pancreatitis presents with:
A) Severe jaundice
B) Bilious vomiting
C) Abdominal pain and elevated lipase
D) Hematemesis
E) Hepatosplenomegaly
Answer: C
Explanation: Mumps pancreatitis is rare but presents with epigastric pain and elevated amylase/lipase.
28
What is the most appropriate treatment for mumps?
A) Acyclovir
B) Ribavirin
C) Supportive care
D) Amoxicillin
E) Ceftriaxone
Answer: C
Explanation: Mumps is viral and self-limited; supportive care is the mainstay.
29
What age is the first MMR vaccine typically administered?
A) Birth
B) 6 weeks
C) 6 months
D) 9 months
E) 12–15 months
Answer: E
Explanation: MMR is given at 12–15 months with a second dose at 4–6 years.
30
Which population has a higher risk of complications from mumps?
A) Neonates
B) Preschool children
C) Adults
D) Vaccinated children
E) Girls < 2 years
Answer: C
Explanation: Complications like orchitis and meningitis are more common in adolescents and adults.
31
What is the typical rash pattern in rubella?
A) Starts at legs and moves up
B) Centripetal distribution
C) Begins on face and spreads caudally
D) Vesicular in nature
E) Petechial and purpuric
Answer: C
Explanation: Rubella rash begins on the face and spreads downward to the trunk and limbs, usually fading by the 3rd day.
32
Which of the following is a classic feature of congenital rubella syndrome (CRS)?
A) Microcephaly
B) PDA
C) Hydrocephalus
D) Jaundice
E) Intestinal atresia
Answer: B
Explanation: Patent ductus arteriosus (PDA) is one of the classic triad findings in CRS (PDA, cataract, deafness).
33
Rubella virus belongs to which family?
A) Togaviridae
B) Paramyxoviridae
C) Flaviviridae
D) Picornaviridae
E) Herpesviridae
Answer: A
Explanation: Rubella is caused by an RNA virus from the Togaviridae family.
34
The most common long-term complication of congenital rubella syndrome is:
A) Vision loss
B) Sensorineural deafness
C) Intellectual disability
D) Diabetes mellitus
E) Seizures
Answer: B
Explanation: Sensorineural hearing loss is the most common and permanent complication of CRS.
35
What is the incubation period of rubella?
A) 3–7 days
B) 7–14 days
C) 14–21 days
D) 21–28 days
E) Over 1 month
Answer: C
Explanation: Rubella has an incubation period of 2–3 weeks, usually around 18 days.
36
Which of the following maternal infections is most likely to cause congenital malformations if contracted during the first trimester?
A) CMV
B) HSV
C) Hepatitis B
D) Rubella
E) Parvovirus B19
Answer: D
Explanation: Rubella in the first trimester carries a high risk (>80%) of congenital defects.
37
Which test confirms recent rubella infection?
A) Anti-rubella IgG
B) Viral culture from CSF
C) Anti-rubella IgM
D) Rubella PCR from urine
E) Chest X-ray
Answer: C
Explanation: Detection of rubella-specific IgM confirms recent or acute infection.
38
Which is not part of the congenital rubella triad?
A) Sensorineural hearing loss
B) PDA
C) Cataract
D) Micrognathia
E) Retinopathy
Answer: D
Explanation: The classical triad: deafness, cardiac defect (PDA), and eye defects (cataract/retinopathy).
39
Which age group is most affected by postnatal rubella?
A) Neonates
B) Toddlers
C) Preschool children
D) Adolescents
E) Elderly
Answer: C
Explanation: Rubella is most common in unvaccinated preschool or school-age children.
40
Rubella virus is primarily transmitted by:
A) Blood
B) Feco-oral route
C) Direct skin contact
D) Respiratory droplets
E) Breastfeeding
Answer: D
Explanation: Airborne droplets are the primary route of rubella transmission.
41
For how long is an infant with congenital rubella considered contagious?
A) 1 week
B) 1 month
C) 6 months
D) Up to 1 year
E) Until symptoms resolve
Answer: D
Explanation: Infants with CRS can shed virus in urine and secretions for up to 1 year.
42
What is the typical duration of rubella rash?
A) <24 hours
B) 2–3 days
C) 5–7 days
D) 7–10 days
E) >2 weeks
Answer: B
Explanation: Rubella rash is short-lived, often resolving in 3 days.
43
What is the mainstay of rubella treatment?
A) Acyclovir
B) Ribavirin
C) Supportive care
D) Azithromycin
E) Interferon
Answer: C
Explanation: Rubella is viral and self-limiting; supportive care is sufficient.
44
What is the classic lymphadenopathy seen in rubella?
A) Inguinal
B) Axillary
C) Occipital and postauricular
D) Mediastinal
E) Epitrochlear
Answer: C
Explanation: Rubella classically causes tender postauricular and occipital lymphadenopathy.
45
The best method to prevent congenital rubella syndrome is:
A) Antiviral therapy in pregnancy
B) Early diagnosis and isolation
C) MMR vaccination in women pre-pregnancy
D) Antibiotic prophylaxis
E) Passive immunization
Answer: C
Explanation: MMR vaccine prior to conception prevents maternal infection and CRS.
46
Which organism causes pertussis?
A) Haemophilus influenzae
B) Bordetella pertussis
C) Corynebacterium diphtheriae
D) Mycoplasma pneumoniae
E) Streptococcus pneumoniae
Answer: B
Explanation: Bordetella pertussis, a gram-negative coccobacillus, is the causative agent of pertussis.
47
What is the hallmark symptom of the paroxysmal stage of pertussis?
A) Sore throat
B) High fever
C) Whooping cough
D) Vomiting
E) Productive cough
Answer: C
Explanation: The paroxysmal stage features intense coughing followed by a 'whoop' on inspiration.
48
Which vaccine is used for pertussis prevention?
A) Hib
B) PCV13
C) DTaP
D) MMR
E) IPV
Answer: C
Explanation: DTaP contains acellular pertussis components for immunization in children.
49
What is the duration of the paroxysmal stage in pertussis?
A) 1–3 days
B) 5–7 days
C) 1–2 weeks
D) 2–6 weeks
E) Over 3 months
Answer: D
Explanation: The paroxysmal phase may last several weeks, with intense coughing spells.
50
Which age group is at highest risk of severe complications from pertussis?
A) School-aged children
B) Adults
C) Infants <6 months
D) Adolescents
E) Elderly
Answer: C
Explanation: Young infants are at high risk for apnea, seizures, pneumonia, and death from pertussis.
51
Which antibiotic is most effective for treating pertussis?
A) Amoxicillin
B) Azithromycin
C) Ceftriaxone
D) Metronidazole
E) Doxycycline
Answer: B
Explanation: Macrolides, especially azithromycin, are first-line treatment, particularly in infants.
52
Pertussis is most contagious during which stage?
A) Incubation
B) Catarrhal
C) Paroxysmal
D) Convalescent
E) Recovery
Answer: B
Explanation: The catarrhal stage, with nonspecific symptoms, is the most contagious period.
53
What is the classic duration of the entire pertussis illness?
A) 1 week
B) 2 weeks
C) 3–6 weeks
D) 6–10 weeks
E) Several months
Answer: D
Explanation: The course progresses through catarrhal, paroxysmal, and convalescent stages over weeks.
54
Post-tussive vomiting is commonly seen in which stage?
A) Catarrhal
B) Incubation
C) Paroxysmal
D) Convalescent
E) Recovery
Answer: C
Explanation: Violent coughing during the paroxysmal phase can cause vomiting afterward.
55
What is a common complication of pertussis in infants?
A) Hematuria
B) Pneumothorax
C) Otitis media
D) Seizures
E) Hemoptysis
Answer: D
Explanation: Apnea, seizures, and encephalopathy are serious complications in young infants.
56
What is the best diagnostic method for early pertussis?
A) Chest X-ray
B) ELISA IgG
C) PCR of nasopharyngeal swab
D) Sputum culture
E) Blood culture
Answer: C
Explanation: PCR from nasopharyngeal secretions is fast and sensitive, especially early in disease.
57
What is the purpose of pertussis post-exposure prophylaxis?
A) Reduce fever
B) Shorten cough duration
C) Prevent spread to close contacts
D) Immunize against diphtheria
E) Replace booster vaccine
Answer: C
Explanation: Azithromycin prophylaxis for household contacts helps limit transmission.
58
What finding may be seen on CBC in a child with pertussis?
A) Neutrophilia
B) Lymphocytosis
C) Eosinophilia
D) Pancytopenia
E) Monocytosis
Answer: B
Explanation: Marked lymphocytosis is characteristic of pertussis due to toxin-mediated effects.
59
What is the mechanism of pertussis toxin?
A) Inhibits protein synthesis
B) Blocks sodium channels
C) Activates adenylate cyclase
D) Destroys alveolar macrophages
E) Inhibits DNA replication
Answer: C
Explanation: Pertussis toxin increases cAMP levels via adenylate cyclase activation, disrupting immune cells.
60
Which booster vaccine is recommended in adolescents and adults?
A) DTaP
B) Hib
C) Tdap
D) MMR
E) BCG
Answer: C
Explanation: Tdap is recommended as a booster for adolescents and adults to maintain pertussis immunity.
61
What is the most common form of TB in children?
A) Miliary TB
B) TB meningitis
C) Primary pulmonary TB
D) Pott’s disease
E) Pleural TB
Answer: C
Explanation: Primary pulmonary TB is the most common form in children, especially under 5 years.
62
Which is the gold standard for diagnosing TB in children?
A) Mantoux test
B) IGRA
C) Sputum smear
D) Mycobacterial culture
E) Chest X-ray
Answer: D
Explanation: Culture remains the gold standard for diagnosing TB, though difficult in children.
63
Which feature is typical of primary complex in pediatric TB?
A) Cavitation
B) Pleural effusion
C) Ghon focus with hilar lymphadenopathy
D) Apical fibrosis
E) Lung abscess
Answer: C
Explanation: The primary complex consists of Ghon focus + regional lymphadenitis.
64
Which symptom is least likely in early pediatric TB?
A) Weight loss
B) Night sweats
C) Persistent cough
D) Hemoptysis
E) Fever
Answer: D
Explanation: Hemoptysis is rare in children; more common in reactivation TB in adults.
65
Which investigation best supports active TB in a child with lymphadenopathy?
A) CBC
B) ESR
C) FNAC with AFB stain
D) CRP
E) Ultrasound
Answer: C
Explanation: Fine needle aspiration cytology with AFB staining helps confirm TB lymphadenitis.
66
What is the typical duration of anti-TB treatment in uncomplicated pediatric pulmonary TB?
A) 2 months
B) 4 months
C) 6 months
D) 9 months
E) 12 months
Answer: C
Explanation: 2 months intensive phase + 4 months continuation phase = 6 months total.
67
Which is a first-line drug in pediatric TB?
A) Streptomycin
B) Levofloxacin
C) Rifampicin
D) Clarithromycin
E) Dapsone
Answer: C
Explanation: Rifampicin is a key first-line agent in RIPE therapy for TB.
68
What is a common side effect of isoniazid in children?
A) Hepatotoxicity
B) Visual loss
C) Skin rash
D) Arthralgia
E) Peripheral neuropathy
Answer: A
Explanation: Isoniazid may cause hepatotoxicity; monitor liver function.
69
What is BCG vaccine’s primary protective effect?
A) Prevents latent TB infection
B) Prevents all forms of TB
C) Prevents pulmonary TB in adults
D) Prevents disseminated and meningeal TB in children
E) Prevents MDR-TB
Answer: D
Explanation: BCG is most effective in preventing severe forms like TB meningitis in young children.
70
Which test is used for TB screening in children under 5?
A) Sputum PCR
B) IGRA
C) GeneXpert
D) Tuberculin skin test
E) Bronchoscopy
Answer: D
Explanation: TST (Mantoux) is commonly used for screening, especially in young children.
71
A child with TB meningitis shows which of the following CSF findings?
A) High glucose
B) Neutrophilic pleocytosis
C) Normal protein
D) Low glucose, high protein, lymphocytosis
E) High chloride
Answer: D
Explanation: Typical TB CSF: low glucose, high protein, and lymphocyte predominance.
72
What is the drug of choice for TB in pregnancy and young children?
A) Streptomycin
B) Ethambutol
C) Isoniazid
D) Ciprofloxacin
E) Amikacin
Answer: C
Explanation: Isoniazid is safe in pregnancy and infants; streptomycin is contraindicated.
73
GeneXpert is particularly useful because it can:
A) Replace culture
B) Detect resistance to rifampicin
C) Identify viral infections
D) Diagnose BCGosis
E) Estimate bacterial load
Answer: B
Explanation: GeneXpert MTB/RIF detects TB DNA and rifampicin resistance rapidly.
74
A child with TB is on treatment and develops red-orange urine. Likely cause?
A) INH
B) Rifampicin
C) Ethambutol
D) Pyrazinamide
E) Streptomycin
Answer: B
Explanation: Rifampicin causes red-orange discoloration of urine, tears, and secretions.
75
What is the recommended prophylaxis for a child <5 years exposed to smear-positive TB?
A) Full 6-month regimen
B) Isoniazid for 6 months
C) BCG vaccine
D) Azithromycin
E) No treatment
Answer: B
Explanation: INH prophylaxis is recommended for high-risk contacts like young children.
76
What is the causative agent of typhoid fever?
A) Salmonella typhi
B) Salmonella paratyphi
C) Shigella dysenteriae
D) Escherichia coli
E) Campylobacter jejuni
Answer: A
Explanation: Salmonella typhi, a gram-negative bacillus, causes typhoid fever.
77
What is the usual route of transmission of typhoid fever?
A) Respiratory droplets
B) Feco-oral
C) Blood transfusion
D) Skin contact
E) Insect bites
Answer: B
Explanation: Contaminated food or water transmits Salmonella via the feco-oral route.
78
Which clinical feature is most characteristic of typhoid fever in children?
A) Sudden onset high-grade fever
B) Step-ladder pattern of fever
C) Productive cough
D) Bloody diarrhea
E) Severe headache
Answer: B
Explanation: Typhoid often presents with a gradual rise in fever ('step-ladder' pattern).
79
Which of the following is most sensitive for early diagnosis of typhoid fever?
A) Widal test
B) Blood culture
C) Stool culture
D) Urine culture
E) IgG serology
Answer: B
Explanation: Blood culture is most sensitive in the first week of illness.
80
What is the gold standard for typhoid diagnosis?
A) Widal test
B) Stool culture
C) PCR
D) Bone marrow culture
E) Serology
Answer: D
Explanation: Bone marrow culture is the most sensitive and is the gold standard.
81
Which of the following is a serious complication of typhoid fever?
A) Peritonitis
B) Seizures
C) Appendicitis
D) Toxic epidermal necrolysis
E) Otitis media
Answer: A
Explanation: Intestinal perforation → peritonitis is a life-threatening complication of typhoid.
82
What is the most common site of intestinal perforation in typhoid?
A) Duodenum
B) Jejunum
C) Terminal ileum
D) Colon
E) Cecum
Answer: C
Explanation: Ulcers typically form in Peyer’s patches of the terminal ileum.
83
Which of the following is used to treat uncomplicated typhoid in children in endemic areas?
A) Ceftriaxone
B) Azithromycin
C) Amoxicillin
D) Ciprofloxacin
E) Metronidazole
Answer: B
Explanation: Azithromycin is effective and increasingly used in areas with resistance to fluoroquinolones.
84
What is the earliest hematological change seen in typhoid fever?
A) Eosinophilia
B) Neutrophilia
C) Leukopenia
D) Thrombocytosis
E) Hemolytic anemia
Answer: C
Explanation: Relative bradycardia and leukopenia are classic early findings.
85
What is the typical finding in Widal test in typhoid fever?
A) O and H agglutinins ≥ 1:80
B) IgG > 500
C) Toxin positivity
D) Rose spots
E) Elevated ESR
Answer: A
Explanation: A significant titer or four-fold rise in O and H agglutinins is suggestive of typhoid.
86
What is the classical skin manifestation of typhoid?
A) Petechiae
B) Erythema nodosum
C) Rose spots
D) Vesicles
E) Bullae
Answer: C
Explanation: Rose-colored macules on the trunk are transient and seen in some children.
87
What is the ideal prevention for typhoid in endemic areas?
A) MMR vaccine
B) Oral typhoid vaccine
C) BCG
D) Tdap
E) Cholera vaccine
Answer: B
Explanation: Oral Ty21a or Vi polysaccharide vaccines are used in high-risk populations.
88
Which lab finding favors typhoid over other febrile illnesses?
A) Neutrophilic leukocytosis
B) High CRP
C) Lymphocytosis
D) Relative bradycardia with leukopenia
E) High procalcitonin
Answer: D
Explanation: The Faget sign (pulse-temperature dissociation) with low WBC suggests typhoid.
89
What is the most common cause of death in untreated typhoid?
A) Sepsis
B) Meningitis
C) GI hemorrhage
D) Perforation and peritonitis
E) Hepatic failure
Answer: D
Explanation: Ileal perforation leads to peritonitis, a major cause of mortality in untreated cases.
90
When should a child be hospitalized for typhoid?
A) All cases
B) Step-ladder fever for 2 days
C) Mild abdominal pain
D) High-grade fever with signs of dehydration or complications
E) Positive Widal only
Answer: D
Explanation: Admission is needed for complicated, toxic, or severely dehydrated children.
91
What is the most common mode of HIV transmission in children?
A) Blood transfusion
B) Sexual abuse
C) Mother-to-child transmission
D) Breastfeeding from HIV-negative mother
E) Sharing utensils
Answer: C
Explanation: Vertical transmission (during pregnancy, delivery, or breastfeeding) is the most common route in children.
92
Which antiretroviral drug is used as neonatal post-exposure prophylaxis (PEP)?
A) Lamivudine
B) Efavirenz
C) Zidovudine
D) Ritonavir
E) Atazanavir
Answer: C
Explanation: Zidovudine is the standard for PEP in neonates born to HIV-positive mothers.
93
At what age is HIV DNA PCR testing first recommended in HIV-exposed infants?
A) At birth
B) 2 weeks
C) 6 weeks
D) 6 months
E) 18 months
Answer: C
Explanation: HIV PCR testing is recommended at 6 weeks to detect early infection in exposed infants.
94
A child with recurrent oral thrush, failure to thrive, and lymphadenopathy should be evaluated for:
A) Tuberculosis
B) Malaria
C) HIV infection
D) Epstein-Barr virus
E) Measles
Answer: C
Explanation: These are classic early signs of pediatric HIV.
95
What is the confirmatory test for HIV in children >18 months?
A) ELISA
B) Western blot or rapid antibody test
C) PCR
D) Viral culture
E) CD4 count
Answer: B
Explanation: Serologic tests are valid after 18 months, when maternal antibodies are no longer interfering.
96
Which vaccine is contraindicated in symptomatic HIV-infected children with low CD4?
A) DTP
B) IPV
C) MMR
D) PCV
E) Hib
Answer: C
Explanation: Live vaccines, like MMR, are contraindicated in severely immunocompromised children.
97
Which of the following is the most common opportunistic infection in pediatric HIV?
A) Cryptosporidiosis
B) CMV retinitis
C) Pneumocystis jiroveci pneumonia (PCP)
D) Histoplasmosis
E) Toxoplasmosis
Answer: C
Explanation: PCP is the most common severe OI in HIV-infected infants, especially in the first year.
98
What is used for PCP prophylaxis in HIV-infected children?
A) Azithromycin
B) Isoniazid
C) Cotrimoxazole
D) Fluconazole
E) Rifampicin
Answer: C
Explanation: Cotrimoxazole (TMP-SMX) prevents PCP and other infections in HIV-exposed and infected children.
99
When should antiretroviral therapy be started in HIV-positive children?
A) Only when symptomatic
B) When CD4 <200
C) At 5 years of age
D) Immediately after diagnosis
E) After 6 months
Answer: D
Explanation: Universal early ART is recommended regardless of CD4 or symptoms.
100
Which lab marker best monitors HIV disease progression in children?
A) WBC count
B) Hemoglobin
C) CD4 count and percentage
D) Platelet count
E) Total protein
Answer: C
Explanation: CD4 count/percentage is used to stage and monitor immune status in HIV.
101
What is the primary aim of ART in children?
A) Cure the disease
B) Decrease growth retardation
C) Improve appetite
D) Suppress viral replication and restore immunity
E) Reduce anemia
Answer: D
Explanation: The goal is to suppress viral load and improve immune function.
102
Breastfeeding recommendation for HIV-positive mothers on ART is:
A) Absolute contraindication
B) Only if no formula is available
C) Exclusive breastfeeding for 6 months
D) Weaning after 2 months
E) Avoided in all situations
Answer: C
Explanation: WHO recommends exclusive breastfeeding with ART cover to reduce risk.
103
Which of the following is a key side effect of nevirapine in children?
A) Hepatotoxicity
B) Peripheral neuropathy
C) Renal failure
D) Visual loss
E) Hair loss
Answer: A
Explanation: Nevirapine may cause liver toxicity, especially early in therapy.
104
Which condition is part of WHO stage 4 (AIDS-defining) in children?
A) Recurrent otitis media
B) Persistent generalized lymphadenopathy
C) Kaposi sarcoma
D) Oral candidiasis
E) Failure to thrive
Answer: C
Explanation: WHO stage 4 includes AIDS-defining illnesses like Kaposi sarcoma.
105
What is the ideal method to reduce vertical transmission during delivery?
A) C-section + ART + avoid breastfeeding
B) Vaginal delivery and formula
C) C-section only
D) Delayed cord clamping
E) Give infant vaccine only
Answer: A
Explanation: This combination minimizes perinatal transmission effectively.
106
What is the causative agent of dengue fever?
A) RNA virus from Flaviviridae family
B) DNA virus from Herpesviridae family
C) RNA virus from Paramyxoviridae family
D) Bacteria from Rickettsia family
E) Protozoan parasite
Answer: A
Explanation: Dengue virus is a single-stranded RNA virus from the Flaviviridae family, with 4 serotypes (DENV-1 to 4).
107
What mosquito is the primary vector of dengue virus?
A) Culex
B) Anopheles
C) Aedes aegypti
D) Aedes albopictus
E) Sandfly
Answer: C
Explanation: Aedes aegypti is the primary vector, known for daytime biting and breeding in clean stagnant water.
108
Which of the following is an early warning sign of severe dengue?
A) Vomiting once
B) Rash
C) Abdominal pain and persistent vomiting
D) Low-grade fever
E) Diarrhea
Answer: C
Explanation: These are clinical warning signs of progression to severe dengue.
109
Which lab test helps predict severe dengue in children?
A) Elevated hemoglobin
B) Low white cell count
C) Rising hematocrit and falling platelets
D) Positive CRP
E) ESR elevation
Answer: C
Explanation: These indicate plasma leakage and impending hemorrhagic complications.
110
What is the best diagnostic test for early dengue infection (days 1–5)?
A) IgG ELISA
B) IgM ELISA
C) NS1 antigen test
D) Dengue PCR
E) Viral culture
Answer: C
Explanation: NS1 antigen is detectable in the early febrile phase (day 1–5).
111
When does the critical phase of dengue usually begin?
A) Day 1 of illness
B) During defervescence (around day 4–6)
C) After 2 weeks
D) After full recovery
E) At the start of rash
Answer: B
Explanation: The critical phase starts as fever subsides, with risk of shock and hemorrhage.
112
What is the mainstay of treatment for dengue?
A) Antibiotics
B) Antivirals
C) Supportive care with fluids
D) Steroids
E) NSAIDs
Answer: C
Explanation: Fluid management is key; no antiviral therapy is available.
113
What drug should be avoided in suspected dengue fever?
A) Paracetamol
B) Ibuprofen
C) ORS
D) Azithromycin
E) Antacids
Answer: B
Explanation: NSAIDs like ibuprofen increase risk of bleeding due to thrombocytopenia.
114
Which sign suggests progression to dengue shock syndrome?
A) Fever
B) Bradycardia
C) Narrow pulse pressure
D) Flushed face
E) Diarrhea
Answer: C
Explanation: Narrowing of pulse pressure (<20 mmHg) indicates circulatory compromise.
115
Which of the following is not a feature of severe dengue?
A) Severe plasma leakage
B) Severe bleeding
C) Hepatic involvement
D) Urticaria
E) Organ impairment
Answer: D
Explanation: Severe dengue includes bleeding, organ dysfunction, and leakage, not skin allergy like urticaria.
116
What fluid is recommended in first-line management of compensated dengue shock?
A) Whole blood
B) Normal saline
C) Ringer's lactate
D) Colloids
E) Dextrose 5%
Answer: B
Explanation: Isotonic crystalloid fluids (e.g., NS) are first-line in compensated shock.
117
What is the role of platelet transfusion in dengue?
A) Always indicated when platelets <150,000
B) Given when petechiae are present
C) Only if active bleeding or platelets <10,000
D) Given as routine
E) Given with every fever spike
Answer: C
Explanation: Prophylactic transfusion is avoided unless there's active bleeding or very low count.
118
A 5-year-old child with dengue fever suddenly collapses on day 4. What is the likely cause?
A) Sepsis
B) Febrile convulsion
C) Dengue shock syndrome
D) Acute liver failure
E) Myocarditis
Answer: C
Explanation: Sudden deterioration during defervescence suggests plasma leakage and shock.
119
Which hematological abnormality is most consistent in dengue?
A) Anemia
B) Neutrophilia
C) Leukopenia and thrombocytopenia
D) Monocytosis
E) Eosinophilia
Answer: C
Explanation: Typical dengue findings include low WBCs and low platelets.
120
Which WHO classification phase is associated with the greatest risk in dengue?
A) Febrile phase
B) Convalescent phase
C) Critical phase
D) Post-illness phase
E) Latent phase
Answer: C
Explanation: Critical phase (days 4–6) carries highest risk of shock, bleeding, and death.
121
What is the most common species causing severe malaria in children?
A) Plasmodium ovale
B) Plasmodium malariae
C) Plasmodium vivax
D) Plasmodium falciparum
E) Plasmodium knowlesi
Answer: D
Explanation: P. falciparum is responsible for most severe and fatal cases, especially in children.
122
Which vector transmits malaria?
A) Aedes mosquito
B) Anopheles mosquito
C) Culex mosquito
D) Tsetse fly
E) Sandfly
Answer: B
Explanation: Female Anopheles mosquitoes transmit malaria parasites during their night-time bite.
123
Which clinical sign is most suggestive of cerebral malaria?
A) Cough
B) Abdominal pain
C) Altered sensorium or seizures
D) Rash
E) Vomiting
Answer: C
Explanation: Cerebral malaria presents with coma, convulsions, or altered mental status.
124
Which lab test confirms malaria diagnosis?
A) Widal test
B) Rapid antigen test or peripheral smear
C) Dengue NS1
D) ESR
E) ELISA for IgG
Answer: B
Explanation: Microscopic examination of blood smear and rapid diagnostic tests (RDT) confirm malaria.
125
Which CBC finding is common in malaria?
A) Neutrophilia
B) Thrombocytopenia
C) Leukocytosis
D) Monocytosis
E) Eosinophilia
Answer: B
Explanation: Low platelet count is frequently observed in both uncomplicated and severe malaria.
126
First-line treatment for uncomplicated falciparum malaria in children is:
A) Quinine sulfate
B) Artesunate monotherapy
C) Chloroquine
D) Artemisinin-based combination therapy (ACT)
E) Doxycycline
Answer: D
Explanation: ACTs (e.g., artemether-lumefantrine) are the preferred treatment for falciparum malaria.
127
What is the drug of choice for cerebral malaria?
A) Oral artemether
B) IV artesunate
C) Chloroquine
D) Oral quinine
E) Mefloquine
Answer: B
Explanation: IV artesunate is the treatment of choice for severe malaria, including cerebral malaria.
128
What electrolyte imbalance is common in severe malaria?
A) Hyperkalemia
B) Hypernatremia
C) Hypoglycemia
D) Hypercalcemia
E) Hyponatremia
Answer: C
Explanation: Hypoglycemia is common, especially in young children or with quinine use.
129
Splenomegaly in malaria is due to:
A) Portal hypertension
B) Parasitic destruction of red cells
C) Nephrotic syndrome
D) Viral hepatitis
E) Tuberculosis
Answer: B
Explanation: Excessive destruction of infected RBCs causes spleen enlargement.
130
Blackwater fever is associated with:
A) Plasmodium vivax
B) Falciparum malaria
C) Chikungunya
D) Dengue
E) Leishmaniasis
Answer: B
Explanation: Blackwater fever = intravascular hemolysis with dark urine, seen in P. falciparum infection.
131
What is the best strategy for malaria prevention in endemic areas?
A) Dengue vaccine
B) Iron supplementation
C) Insecticide-treated bed nets (ITNs)
D) Vitamin A
E) BCG vaccine
Answer: C
Explanation: Sleeping under ITNs significantly reduces malaria transmission.
132
Which antimalarial is contraindicated in G6PD deficiency?
A) Chloroquine
B) Primaquine
C) Artesunate
D) Lumefantrine
E) Doxycycline
Answer: B
Explanation: Primaquine can trigger hemolysis in G6PD-deficient children.
133
Which clinical feature distinguishes malaria from typhoid in children?
A) High fever
B) Step-ladder fever
C) Fever with chills and rigors
D) Vomiting
E) Anemia
Answer: C
Explanation: Malaria often presents with intermittent high fever with chills and rigors.
134
In severe malaria, fluid management should be:
A) Aggressive hydration
B) IV dextrose only
C) Balanced and cautious
D) No fluids at all
E) Oral ORS only
Answer: C
Explanation: Overhydration may worsen outcomes; cautious fluid therapy is recommended.
135
Which of the following is used for radical cure of Plasmodium vivax malaria?
A) Chloroquine only
B) Artesunate
C) Primaquine
D) Lumefantrine
E) Paracetamol
Answer: C
Explanation: Primaquine clears hypnozoites of P. vivax and P. ovale, preventing relapse.
136
What is the causative organism of tetanus?
A) Clostridium difficile
B) Clostridium botulinum
C) Clostridium tetani
D) Corynebacterium diphtheriae
E) Bacillus anthracis
Answer: C
Explanation: Clostridium tetani is an anaerobic, spore-forming gram-positive bacillus that produces tetanospasmin toxin.
137
What is the main toxin responsible for tetanus symptoms?
A) Exotoxin A
B) Tetanospasmin
C) Neurotoxin B
D) Botulinum toxin
E) Enterotoxin
Answer: B
Explanation: Tetanospasmin is a neurotoxin that blocks inhibitory neurotransmitters, causing sustained muscle contraction.
138
What is the hallmark clinical feature of tetanus?
A) Maculopapular rash
B) Flaccid paralysis
C) Spastic muscle rigidity
D) Hemorrhagic shock
E) Ascending paralysis
Answer: C
Explanation: Tetanus is marked by muscle stiffness, especially trismus (lockjaw) and opisthotonos.
139
Neonatal tetanus commonly results from:
A) Maternal HIV
B) Use of contaminated instruments for umbilical cord care
C) Preterm delivery
D) Genetic mutation
E) Breastfeeding
Answer: B
Explanation: Neonatal tetanus often occurs when unclean blades are used to cut the umbilical cord.
140
Which neurotransmitters are inhibited by tetanospasmin?
A) GABA and glycine
B) Acetylcholine and dopamine
C) Glutamate and serotonin
D) Dopamine and epinephrine
E) Serotonin and norepinephrine
Answer: A
Explanation: Tetanospasmin blocks GABA and glycine, causing uncontrolled motor neuron excitation.
141
What is the incubation period for tetanus?
A) 1–3 days
B) 5–10 days
C) 14–21 days
D) 1 month
E) 2–3 hours
Answer: B
Explanation: The typical incubation period ranges from 5 to 10 days after exposure.
142
Which is the most severe form of tetanus?
A) Localized
B) Cephalic
C) Generalized
D) Neonatal
E) Post-vaccination
Answer: C
Explanation: Generalized tetanus is the most common and severe, affecting multiple muscle groups.
143
Which is a common early symptom of tetanus?
A) Rash
B) Trismus (lockjaw)
C) Diarrhea
D) Vomiting
E) Hematuria
Answer: B
Explanation: Trismus is often the first clinical sign of tetanus, due to masseter muscle spasm.
144
What is the role of tetanus immunoglobulin (TIG)?
A) Neutralizes circulating toxin
B) Kills the bacteria
C) Replaces antibodies
D) Stimulates toxin production
E) Inhibits spore germination
Answer: A
Explanation: TIG binds and neutralizes unbound tetanospasmin to prevent progression.
145
Which antibiotic is preferred in tetanus management?
A) Amoxicillin
B) Ciprofloxacin
C) Metronidazole
D) Azithromycin
E) Ceftriaxone
Answer: C
Explanation: Metronidazole is preferred for anaerobic coverage against Clostridium tetani.
146
What supportive measure is critical in severe tetanus cases?
A) Oral hydration
B) Nasogastric feeding
C) Mechanical ventilation
D) Hemodialysis
E) Blood transfusion
Answer: C
Explanation: Ventilatory support is often required due to respiratory muscle rigidity.
147
What is the role of diazepam in tetanus?
A) Antibiotic
B) Immunoglobulin substitute
C) Muscle relaxant and anticonvulsant
D) Anti-inflammatory
E) Steroid
Answer: C
Explanation: Diazepam is used to control spasms and seizures in tetanus.
148
How is tetanus prevented in neonates?
A) Exclusive breastfeeding
B) Oral antibiotics
C) Maternal immunization with TT vaccine
D) Early clamping of cord
E) Delayed bathing
Answer: C
Explanation: TT immunization in pregnancy protects both mother and newborn.
149
What is the status of tetanus immunity after recovery?
A) Permanent lifelong
B) Short term (6 months)
C) None – active immunization still needed
D) Partial
E) Maternal only
Answer: C
Explanation: Natural infection does not confer immunity; vaccination is required post-recovery.
150
What is the first-line wound care in tetanus prevention?
A) Ice packing
B) No treatment
C) Surgical debridement
D) Antihistamines
E) Ointment application
Answer: C
Explanation: Debridement reduces bacterial load and spore count at the wound site.
151
What is the causative agent of Scarlet Fever?
A) Streptococcus agalactiae
B) Streptococcus pyogenes (Group A)
C) Corynebacterium diphtheriae
D) Staphylococcus aureus
E) Haemophilus influenzae
Answer: B
Explanation: Scarlet fever is caused by Group A Streptococcus producing erythrogenic exotoxins.
152
What is the typical age group affected by Scarlet Fever?
A) Neonates
B) <1 year
C) 2–10 years
D) Adolescents
E) Adults
Answer: C
Explanation: Most cases occur in school-age children, with rare cases in infants.
153
What type of rash is seen in Scarlet Fever?
A) Vesicular
B) Maculopapular
C) Sandpaper-like erythematous rash
D) Petechial
E) Urticarial
Answer: C
Explanation: The rash feels like sandpaper and typically starts on the trunk.
154
Which sign is classically seen on the tongue in Scarlet Fever?
A) Geographic tongue
B) Strawberry tongue
C) Hairy tongue
D) Smooth tongue
E) Black tongue
Answer: B
Explanation: Initially white, then red strawberry tongue is characteristic.
155
How is Scarlet Fever transmitted?
A) Vertical transmission
B) Fecal-oral route
C) Airborne droplets
D) Vector-borne
E) Skin contact only
Answer: C
Explanation: It spreads via respiratory droplets from infected individuals.
156
What is the incubation period of Scarlet Fever?
A) 1–2 days
B) 2–5 days
C) 6–10 days
D) 10–14 days
E) >2 weeks
Answer: B
Explanation: Symptoms typically appear 2–5 days after exposure.
157
What is Pastia’s sign in Scarlet Fever?
A) Flaring of the nostrils
B) Blanching rash on the trunk
C) Hyperpigmented linear rash in skin folds
D) Petechiae over hard palate
E) Conjunctival hemorrhage
Answer: C
Explanation: Pastia’s lines appear in antecubital and inguinal folds.
158
Which test confirms Streptococcus pyogenes infection?
A) Monospot
B) Throat swab culture or rapid antigen test
C) Widal test
D) Blood culture
E) ESR
Answer: B
Explanation: Throat culture remains the gold standard; rapid strep test is commonly used.
159
What is the first-line treatment of Scarlet Fever?
A) Azithromycin
B) Amoxicillin-clavulanate
C) Penicillin or amoxicillin
D) Ceftriaxone
E) Doxycycline
Answer: C
Explanation: 10-day course of penicillin or amoxicillin is standard therapy.
160
In penicillin-allergic children, what is the alternative treatment?
A) Gentamicin
B) Clarithromycin
C) Metronidazole
D) Rifampicin
E) Levofloxacin
Answer: B
Explanation: Macrolides (e.g., clarithromycin) are suitable alternatives.
161
What complication is associated with Scarlet Fever?
A) Rheumatic fever
B) Kawasaki disease
C) G6PD deficiency
D) Typhoid fever
E) Tetanus
Answer: A
Explanation: Untreated strep infection may lead to rheumatic fever or glomerulonephritis.
162
Which clinical feature helps differentiate Scarlet Fever from viral exanthems?
A) Fever
B) Conjunctivitis
C) Sandpaper rash + pharyngitis
D) Rash sparing face
E) Vomiting
Answer: C
Explanation: The combination of sore throat, fever, and typical rash points to Scarlet Fever.
163
When is a child with Scarlet Fever no longer contagious?
A) After 10 days
B) After 7 days of illness
C) 24 hours after starting antibiotics
D) When fever resolves
E) When rash disappears
Answer: C
Explanation: Infectivity is greatly reduced after 24 hours of effective antibiotic therapy.
164
What causes the rash in Scarlet Fever?
A) Viral replication
B) IgE release
C) Erythrogenic exotoxin
D) Bacterial superinfection
E) Fungal colonization
Answer: C
Explanation: The rash is toxin-mediated — caused by Group A Strep exotoxins.
165
Desquamation after Scarlet Fever occurs in which area first?
A) Chest
B) Abdomen
C) Palms and soles
D) Face
E) Back
Answer: C
Explanation: Skin peeling begins in the palms and soles, typically after the rash fades.
166
What is the causative organism of leptospirosis?
A) Leptospira interrogans
B) Salmonella typhi
C) Borrelia burgdorferi
D) Rickettsia rickettsii
E) Treponema pallidum
Answer: A
Explanation: Leptospirosis is caused by the spirochete bacterium Leptospira interrogans.
167
How is leptospirosis commonly transmitted?
A) Airborne droplets
B) Blood transfusion
C) Contact with water contaminated with animal urine
D) Insect bite
E) Sexual contact
Answer: C
Explanation: It is transmitted through broken skin or mucosa contacting water contaminated by infected animal urine.
168
Which organ systems are primarily affected in leptospirosis?
A) CNS and endocrine
B) Liver and kidneys
C) Lungs and heart
D) Skin and bones
E) GI and muscles
Answer: B
Explanation: Liver and kidney involvement are hallmark features; may cause jaundice and renal failure.
169
What is Weil’s disease?
A) Mild form of leptospirosis
B) A neurological manifestation
C) Severe leptospirosis with jaundice, renal failure, bleeding
D) Viral encephalitis
E) Scarlet fever
Answer: C
Explanation: Weil’s disease is the severe form of leptospirosis with hepatic and renal dysfunction.
170
Which of the following is a common symptom in pediatric leptospirosis?
A) Maculopapular rash
B) Headache and muscle pain
C) Petechiae
D) Dry cough
E) Wheezing
Answer: B
Explanation: Children often present with fever, headache, myalgia, and vomiting.
171
Which lab finding is often seen in leptospirosis?
A) Leukopenia
B) Thrombocytopenia
C) Eosinophilia
D) Hypernatremia
E) Elevated amylase
Answer: B
Explanation: Thrombocytopenia is common in leptospirosis, especially in severe cases.
172
Which liver enzyme abnormality is typical in leptospirosis?
A) Mild transaminase elevation with hyperbilirubinemia
B) AST>ALT in thousands
C) ALP elevation only
D) GGT only
E) Ammonia elevation
Answer: A
Explanation: Leptospirosis causes mild-moderate transaminitis with high bilirubin (often conjugated).
173
Which diagnostic test is most specific for leptospirosis?
A) Widal test
B) Blood smear
C) Microscopic agglutination test (MAT)
D) ELISA for IgG
E) Urinalysis
Answer: C
Explanation: MAT is the gold standard; detects antibodies to Leptospira.
174
Which antibiotic is the treatment of choice for moderate to severe leptospirosis in children?
A) Ceftriaxone
B) Penicillin G or doxycycline
C) Erythromycin
D) Ciprofloxacin
E) Metronidazole
Answer: B
Explanation: Penicillin G or doxycycline is used depending on age and severity.
175
Which complication is common in severe leptospirosis?
A) Hypoglycemia
B) Hepatic encephalopathy
C) Pulmonary hemorrhage and renal failure
D) Cardiac tamponade
E) Pancreatitis
Answer: C
Explanation: Severe cases may involve pulmonary hemorrhage, acute renal failure, and multiorgan dysfunction.
176
What is the mainstay of supportive therapy in leptospirosis?
A) Blood transfusion
B) Ventilation
C) Hydration and electrolyte balance
D) Hemodialysis
E) Corticosteroids
Answer: C
Explanation: IV fluids and renal support are essential in managing complications.
177
Which is a known reservoir of leptospira?
A) Mosquitoes
B) Birds
C) Rats and rodents
D) Cats
E) Humans only
Answer: C
Explanation: Rodents, especially rats, are common reservoirs shedding leptospira in urine.
178
What is the incubation period of leptospirosis?
A) 1–2 days
B) 3–7 days
C) 7–14 days
D) 15–30 days
E) 1–2 months
Answer: C
Explanation: The incubation period is generally between 7–14 days after exposure.
179
Which sign is most helpful to distinguish leptospirosis from dengue?
A) Bleeding
B) Elevated bilirubin and creatinine
C) Thrombocytopenia
D) Fever
E) Rash
Answer: B
Explanation: Leptospirosis involves hepatic and renal dysfunction, unlike dengue.
180
What prevention strategy reduces leptospirosis transmission?
A) Measles vaccine
B) Avoiding stagnant water
C) Hand sanitizer
D) DPT immunization
E) Air purification
Answer: B
Explanation: Avoiding contaminated water sources reduces risk of infection.
181
What is the causative agent of diphtheria?
A) Corynebacterium diphtheriae
B) Bordetella pertussis
C) Haemophilus influenzae
D) Streptococcus pyogenes
E) Neisseria meningitidis
Answer: A
Explanation: Diphtheria is caused by Corynebacterium diphtheriae, a gram-positive bacillus.
182
What is the characteristic throat finding in diphtheria?
A) Tonsillar hypertrophy
B) White coating on the tongue
C) Pseudomembrane formation
D) Petechial rash
E) Ulceration
Answer: C
Explanation: A hallmark is a thick gray-white pseudomembrane on the tonsils, pharynx, or nasal mucosa.
183
How is diphtheria transmitted?
A) Fecal-oral
B) Vector-borne
C) Airborne droplets
D) Sexual contact
E) Vertical
Answer: C
Explanation: Diphtheria spreads through respiratory droplets and close contact.
184
Which toxin is responsible for diphtheria complications?
A) Botulinum toxin
B) Diphtheria toxin
C) Tetanospasmin
D) Lipopolysaccharide
E) Pertussis toxin
Answer: B
Explanation: The diphtheria toxin inhibits protein synthesis and is responsible for systemic effects.
185
What is a life-threatening complication of diphtheria?
A) Otitis media
B) Myocarditis
C) Pneumonia
D) Renal failure
E) Hepatitis
Answer: B
Explanation: Myocarditis due to diphtheria toxin can lead to heart failure and arrhythmias.
186
What neurological complication can occur in diphtheria?
A) Seizures
B) Guillain-Barré syndrome
C) Cranial nerve palsy
D) Spinal cord compression
E) Stroke
Answer: C
Explanation: Cranial neuropathies (especially palatal paralysis) are a known complication.
187
Which culture medium is used to isolate C. diphtheriae?
A) Thayer-Martin
B) Chocolate agar
C) Löeffler or Tinsdale agar
D) Blood agar
E) MacConkey agar
Answer: C
Explanation: Löeffler and Tinsdale media are selective for Corynebacterium diphtheriae.
188
What is the first-line treatment for diphtheria?
A) Amoxicillin
B) Macrolide or penicillin + antitoxin
C) Ceftriaxone
D) Vancomycin
E) Doxycycline
Answer: B
Explanation: Treatment includes antibiotics plus diphtheria antitoxin to neutralize circulating toxin.
189
How does diphtheria antitoxin work?
A) Destroys bacteria
B) Kills spores
C) Neutralizes free toxin
D) Boosts immunity
E) Replaces enzymes
Answer: C
Explanation: The antitoxin binds to unbound diphtheria toxin, preventing further damage.
190
What is the recommended antibiotic for diphtheria in children?
A) Penicillin G
B) Azithromycin
C) Cefixime
D) Rifampin
E) Isoniazid
Answer: A
Explanation: Penicillin G or erythromycin is recommended to eradicate the organism.
191
What vaccine prevents diphtheria?
A) MMR
B) DTaP
C) BCG
D) IPV
E) Hib
Answer: B
Explanation: Diphtheria is prevented by the DTaP vaccine (diphtheria, tetanus, and pertussis).
192
What is the dosing schedule for DTaP in infants?
A) Birth, 6, 12 months
B) 2, 4, 6 months and boosters
C) 1, 5, 10 years
D) Every year
E) Only once at 6 weeks
Answer: B
Explanation: DTaP is given at 2, 4, and 6 months, with boosters at 15–18 months and 4–6 years.
193
How long should a diphtheria patient be isolated after starting antibiotics?
A) 24 hours
B) 2 days
C) Until fever subsides
D) 48 hours and 2 negative cultures
E) 10 days
Answer: D
Explanation: Isolation continues until 2 consecutive negative throat cultures taken after 48 hours of antibiotics.
194
What is the role of booster doses in diphtheria prevention?
A) No need if primary completed
B) Given annually
C) Maintain long-term immunity
D) Only in adults
E) Given after infection
Answer: C
Explanation: Booster doses help maintain protective antibody levels against diphtheria.
195
What is the purpose of contact tracing in diphtheria cases?
A) Legal documentation
B) Academic research
C) Identify and treat close contacts
D) Environmental control
E) Travel history
Answer: C
Explanation: Close contacts should be identified and treated with antibiotics and monitored.
196
What is the causative agent of varicella (chickenpox)?
A) Herpes simplex virus type 1
B) Varicella-zoster virus
C) Epstein-Barr virus
D) Cytomegalovirus
E) Measles virus
Answer: B
Explanation: Varicella is caused by the varicella-zoster virus (VZV), a member of the herpesvirus family.
197
What is the typical rash pattern in varicella?
A) Petechial rash on lower limbs
B) Maculopapular rash with crusting
C) Crops of lesions in different stages of evolution
D) Linear vesicles
E) Confluent macules
Answer: C
Explanation: Chickenpox rash appears in crops of macules, papules, vesicles, and crusts simultaneously.
198
What is the primary route of transmission for varicella?
A) Fecal-oral
B) Skin contact
C) Airborne and direct contact
D) Bloodborne
E) Vector-borne
Answer: C
Explanation: VZV is transmitted through airborne droplets and direct contact with lesions.
199
What is the incubation period for varicella?
A) 2–4 days
B) 4–7 days
C) 7–10 days
D) 10–21 days
E) 21–30 days
Answer: D
Explanation: The incubation period ranges from 10 to 21 days, most commonly around 14 days.
200
Which complication is most common in children with varicella?
A) Hepatitis
B) Encephalitis
C) Secondary bacterial skin infection
D) Thrombocytopenia
E) Pneumonia
Answer: C
Explanation: Impetiginization or cellulitis from scratching is the most common complication in children.
201
Which of the following is a serious complication more common in adults?
A) Otitis media
B) Appendicitis
C) Varicella pneumonia
D) Sepsis
E) Myocarditis
Answer: C
Explanation: Varicella pneumonia is more severe and more common in adults than in children.
202
When is a patient with varicella considered contagious?
A) From 1 day after rash
B) Only while feverish
C) From 48 hours before rash until all lesions crusted
D) Only when vesicles are present
E) Until fever subsides
Answer: C
Explanation: Infectious from 1–2 days before rash until all lesions are crusted (~5–7 days).
203
What is the first-line antiviral treatment for complicated varicella?
A) Oseltamivir
B) Ribavirin
C) Acyclovir
D) Ganciclovir
E) Valganciclovir
Answer: C
Explanation: Acyclovir is the preferred antiviral, especially in immunocompromised or severe cases.
204
When is varicella-zoster immune globulin (VZIG) indicated?
A) All contacts
B) In vaccinated children
C) In high-risk exposed individuals
D) For neonates with rash
E) Only for adults
Answer: C
Explanation: VZIG is used post-exposure in high-risk groups: immunocompromised, pregnant, or neonates.
205
What is the recommended age for first dose of varicella vaccine?
A) At birth
B) 6 weeks
C) 9 months
D) 12–15 months
E) 5 years
Answer: D
Explanation: The first dose is typically given between 12–15 months of age.
206
How many doses of varicella vaccine are given in childhood immunization?
A) 1
B) 2
C) 3
D) 4
E) None
Answer: B
Explanation: Two doses are recommended: at 12–15 months and at 4–6 years of age.
207
Which group is most likely to develop disseminated varicella?
A) Healthy children
B) Infants <6 months
C) Adolescents
D) Immunocompromised children
E) Vaccinated toddlers
Answer: D
Explanation: Immunocompromised individuals are at high risk of disseminated varicella.
208
What laboratory test is used to confirm varicella diagnosis in atypical cases?
A) Throat swab culture
B) Widal test
C) PCR for VZV
D) Tuberculin test
E) Rapid influenza test
Answer: C
Explanation: PCR testing for VZV is the most sensitive and specific test for varicella.
209
Which of the following best describes post-exposure prophylaxis for varicella?
A) Penicillin within 24 hours
B) VZIG within 96 hours
C) Varicella vaccine after 10 days
D) Acyclovir after rash
E) No need for any prophylaxis
Answer: B
Explanation: VZIG should be administered within 96 hours of exposure in eligible individuals.
210
Which feature differentiates varicella from smallpox?
A) High fever
B) Vesicular rash
C) Lesions in different stages
D) Lymphadenopathy
E) Itchy rash
Answer: C
Explanation: Varicella has lesions in various stages; smallpox lesions are all at the same stage.
211
What is the causative agent of Chikungunya?
A) Flavivirus
B) Paramyxovirus
C) Togavirus (Alphavirus)
D) Retrovirus
E) Bunyavirus
Answer: C
Explanation: Chikungunya is caused by an alphavirus from the Togaviridae family.
212
How is Chikungunya transmitted?
A) Respiratory droplets
B) Contaminated food
C) Mosquito bites
D) Direct contact
E) Blood transfusion
Answer: C
Explanation: Chikungunya is transmitted by Aedes mosquitoes, especially Aedes aegypti and Aedes albopictus.
213
What is a typical symptom of Chikungunya infection in children?
A) Profuse watery diarrhea
B) Severe polyarthritis
C) Chronic cough
D) Hematuria
E) Bradycardia
Answer: B
Explanation: Chikungunya classically causes sudden fever with polyarthritis or arthralgia.
214
What is the usual incubation period for Chikungunya?
A) 1–2 days
B) 3–7 days
C) 8–14 days
D) 15–20 days
E) >21 days
Answer: B
Explanation: Symptoms typically develop within 3–7 days after a mosquito bite.
215
Which joint involvement is typical of Chikungunya?
A) Monoarthritis of hip
B) Asymmetric large joints
C) Symmetrical polyarthritis
D) Dactylitis
E) Sacroiliitis
Answer: C
Explanation: Chikungunya causes symmetrical polyarthritis resembling rheumatoid arthritis.
216
Which laboratory finding is often seen in Chikungunya?
A) Leukocytosis
B) Thrombocytosis
C) Leukopenia
D) High ESR only
E) Eosinophilia
Answer: C
Explanation: Leukopenia is commonly seen during the febrile phase of Chikungunya.
217
What is the best test for early diagnosis of Chikungunya?
A) Widal test
B) RT-PCR for viral RNA
C) ELISA IgG
D) Mantoux test
E) Blood culture
Answer: B
Explanation: RT-PCR can detect viral RNA in the first few days of illness.
218
What is the role of ELISA IgM in Chikungunya diagnosis?
A) Detects chronic carriers
B) Detects acute infection after 5 days
C) Screens for vaccine response
D) Confirms congenital disease
E) Not used
Answer: B
Explanation: IgM antibodies become detectable ~5 days after symptom onset and confirm recent infection.
219
What is the mainstay of treatment for Chikungunya in children?
A) Antibiotics
B) Antivirals
C) Supportive care with fluids and paracetamol
D) Corticosteroids
E) NSAIDs only
Answer: C
Explanation: Treatment is symptomatic, with paracetamol for fever and fluids for hydration.
220
Which drug should be avoided initially in suspected Chikungunya cases?
A) Paracetamol
B) Ibuprofen
C) Acetaminophen
D) Azithromycin
E) Ceftriaxone
Answer: B
Explanation: NSAIDs like ibuprofen are avoided initially due to risk of dengue co-infection.
221
Which of the following is a complication of pediatric Chikungunya?
A) Liver failure
B) Hemolytic anemia
C) Chronic arthritis
D) Hypertensive crisis
E) Aplastic anemia
Answer: C
Explanation: Persistent arthritis/arthralgia can occur even in children for weeks to months.
222
Which mosquito control strategy helps prevent Chikungunya?
A) Bed nets only
B) Water sanitation
C) Elimination of breeding sites of Aedes
D) Use of vaccines
E) Deworming
Answer: C
Explanation: Eliminating stagnant water and using repellents reduce mosquito breeding and bites.
223
Which population is at risk of severe Chikungunya?
A) Adolescents only
B) Neonates and elderly
C) Athletes
D) Vaccinated individuals
E) Healthy children
Answer: B
Explanation: Neonates, elderly, and immunocompromised are more likely to have complications.
224
How long can Chikungunya virus persist in joints?
A) Less than 5 days
B) 1–2 weeks
C) Up to 1 month
D) Several months
E) Lifetime
Answer: D
Explanation: Viral antigen and inflammation may persist in joints for several months, causing chronic symptoms.
225
What differentiates Chikungunya from Dengue clinically?
A) Severe thrombocytopenia
B) High fever
C) Prominent joint pain
D) Rash
E) Vomiting
Answer: C
Explanation: Chikungunya presents with more severe and prolonged joint pain compared to Dengue.
226
What is the most common species causing human brucellosis?
A) Brucella melitensis
B) Brucella abortus
C) Brucella suis
D) Brucella canis
E) Brucella ovis
Answer: A
Explanation: Brucella melitensis is the most pathogenic and common species in humans.
227
What is the most common mode of transmission of brucellosis in children?
A) Sexual contact
B) Respiratory droplets
C) Consumption of unpasteurized dairy
D) Vector bite
E) Blood transfusion
Answer: C
Explanation: Brucella is typically transmitted via ingestion of contaminated milk or cheese.
228
Which symptom is most typical in pediatric brucellosis?
A) Hematuria
B) Intermittent fever with night sweats
C) Productive cough
D) Severe diarrhea
E) Rash
Answer: B
Explanation: Intermittent or undulant fever, often with night sweats and fatigue, is characteristic.
229
Which organ system is most commonly involved in brucellosis?
A) Gastrointestinal
B) Neurological
C) Musculoskeletal
D) Dermatologic
E) Respiratory
Answer: C
Explanation: Musculoskeletal complaints such as arthralgia, arthritis, or sacroiliitis are common.
230
Which of the following is a complication of untreated brucellosis?
A) Nephrotic syndrome
B) Osteomyelitis
C) Bronchiectasis
D) Retinopathy
E) Addison’s disease
Answer: B
Explanation: Brucella can cause focal infections including osteomyelitis and sacroiliitis.
231
What is the gold standard for diagnosis of brucellosis?
A) ELISA IgM
B) Bone marrow culture
C) Widal test
D) Urine culture
E) Serology
Answer: B
Explanation: Bone marrow culture is the most sensitive test for diagnosing brucellosis.
232
What is the standard serologic test used for diagnosis?
A) Paul-Bunnell test
B) Widal test
C) Standard agglutination test (SAT)
D) Weil-Felix test
E) CRP
Answer: C
Explanation: SAT detects antibodies against Brucella and is widely used in endemic areas.
233
Which finding supports chronic brucellosis?
A) High-grade fever with neutrophilia
B) Splenomegaly and anemia
C) Acute rash
D) Hyperkalemia
E) Jaundice
Answer: B
Explanation: Chronic brucellosis may present with hepatosplenomegaly, anemia, and weight loss.
234
What is the first-line antibiotic regimen in children over 8 years?
A) Penicillin + ceftriaxone
B) Amoxicillin + gentamicin
C) Doxycycline + rifampin
D) Vancomycin + linezolid
E) Azithromycin + cefixime
Answer: C
Explanation: Doxycycline with rifampin for 6 weeks is the preferred regimen in older children.
235
What is the alternative regimen in children under 8 years?
A) Clarithromycin + ciprofloxacin
B) Trimethoprim-sulfamethoxazole + rifampin
C) Doxycycline + ampicillin
D) Cefixime + rifampin
E) Chloramphenicol alone
Answer: B
Explanation: TMP-SMX with rifampin is used for children under 8 due to concerns with doxycycline.
236
Which of the following is an occupational risk for brucellosis?
A) Software engineer
B) Teacher
C) Veterinarian
D) Pharmacist
E) Taxi driver
Answer: C
Explanation: Veterinarians and abattoir workers have increased risk of exposure to Brucella.
237
What is the duration of antibiotic therapy in brucellosis?
A) 5 days
B) 7–10 days
C) 2 weeks
D) At least 6 weeks
E) Lifetime prophylaxis
Answer: D
Explanation: A minimum of 6 weeks of combination therapy is required to reduce relapse.
238
Which symptom supports diagnosis of neurobrucellosis?
A) Cough and wheeze
B) Hematuria
C) Headache, meningism, cranial nerve palsies
D) Visual hallucinations
E) Gastrointestinal bleeding
Answer: C
Explanation: Neurobrucellosis may present with meningitis or cranial nerve involvement.
239
Which test is most helpful to confirm relapse?
A) Repeat chest x-ray
B) SAT titer increase
C) ESR drop
D) Widal titer
E) Creatinine clearance
Answer: B
Explanation: Rising antibody titers or positive cultures may indicate relapse.
240
Which public health measure helps prevent brucellosis?
A) Water chlorination
B) Air filters
C) Pasteurization of milk
D) Mass antibiotic prophylaxis
E) Mosquito control
Answer: C
Explanation: Consuming pasteurized dairy products greatly reduces risk of Brucella infection.
241
What is the causative virus for COVID-19?
A) SARS-CoV
B) MERS-CoV
C) SARS-CoV-2
D) Influenza A
E) RSV
Answer: C
Explanation: COVID-19 is caused by the novel coronavirus SARS-CoV-2.
242
How is COVID-19 primarily transmitted?
A) Fecal-oral route
B) Mosquito bites
C) Respiratory droplets and aerosols
D) Contaminated water
E) Skin contact
Answer: C
Explanation: SARS-CoV-2 spreads mainly via respiratory droplets and aerosols.
243
Which of the following symptoms is most common in pediatric COVID-19?
A) Chest pain
B) Gastrointestinal symptoms
C) Hematuria
D) Petechial rash
E) Jaundice
Answer: B
Explanation: Children often present with GI symptoms such as diarrhea, nausea, and abdominal pain.
244
Which pediatric population is at higher risk of severe COVID-19?
A) Healthy children
B) Children with asthma
C) Children with obesity or comorbidities
D) Neonates only
E) Adolescents only
Answer: C
Explanation: Children with underlying conditions like obesity, heart disease, or immunosuppression are at increased risk.
245
What is MIS-C in the context of COVID-19?
A) Mild Influenza Syndrome in Children
B) Multisystem Inflammatory Syndrome in Children
C) Muscle Injury Syndrome
D) Mental Impact Syndrome of COVID
E) Moderate Infection Stage in Children
Answer: B
Explanation: MIS-C is a rare but serious post-COVID condition causing systemic inflammation.
246
When does MIS-C typically appear after COVID-19 infection?
A) 1–2 days
B) During acute infection
C) 2–6 weeks after infection
D) Immediately post-vaccination
E) Years later
Answer: C
Explanation: MIS-C often occurs 2–6 weeks after COVID-19 infection or exposure.
247
Which lab findings support the diagnosis of MIS-C?
A) Neutropenia and high ferritin
B) High CRP, D-dimer, ferritin
C) High calcium and uric acid
D) Low platelets and high bilirubin
E) Low WBC and ESR
Answer: B
Explanation: Inflammatory markers like CRP, D-dimer, and ferritin are elevated in MIS-C.
248
Which is a common cardiac manifestation of MIS-C?
A) Pericardial effusion
B) Bradycardia
C) Kawasaki-like coronary dilation
D) Atrial fibrillation
E) Mitral stenosis
Answer: C
Explanation: MIS-C can mimic Kawasaki disease with coronary artery abnormalities.
249
What is the first-line treatment for MIS-C?
A) High-dose steroids alone
B) Aspirin and fluids
C) IVIG with or without corticosteroids
D) Antibiotics only
E) Plasma exchange
Answer: C
Explanation: IVIG, often combined with corticosteroids, is the primary treatment for MIS-C.
250
What is the preferred diagnostic test for active SARS-CoV-2 infection?
A) IgG serology
B) Chest x-ray
C) RT-PCR
D) D-dimer
E) ESR
Answer: C
Explanation: RT-PCR from nasopharyngeal swab is the gold standard for detecting active infection.
251
Which pediatric age group most commonly develops MIS-C?
A) <1 year
B) 1–4 years
C) 5–11 years
D) 12–18 years
E) Adults only
Answer: C
Explanation: MIS-C occurs most frequently in children aged 5–11 years.
252
What is the role of COVID-19 vaccination in children?
A) Prevents all symptoms
B) Causes MIS-C
C) Reduces risk of severe disease and MIS-C
D) Only for adults
E) Contraindicated in asthma
Answer: C
Explanation: Vaccination helps reduce the severity of disease and incidence of MIS-C.
253
What is the isolation period for mild pediatric COVID-19 cases?
A) 2 days
B) Until fever subsides
C) 5–10 days from symptom onset
D) 21 days
E) Until PCR negative
Answer: C
Explanation: Current guidelines recommend 5–10 days of isolation depending on symptoms.
254
Which imaging finding may be seen in severe pediatric COVID-19?
A) Cavitations
B) Bilateral ground-glass opacities
C) Single large lobe consolidation
D) Hilar adenopathy
E) Pleural effusion only
Answer: B
Explanation: Chest CT or x-ray may show bilateral ground-glass opacities in moderate to severe cases.
255
What is the prognosis of pediatric COVID-19 in general?
A) Poor
B) High mortality
C) Mostly mild and self-limited
D) Always severe
E) Requires ICU in all cases
Answer: C
Explanation: Most children experience mild symptoms and recover without complications.
256
What is the most common causative agent of HFMD?
A) Coxsackievirus A16
B) Enterovirus D68
C) Echovirus 11
D) Influenza A
E) RSV
Answer: A
Explanation: Coxsackievirus A16 is the most frequent cause; Enterovirus 71 may cause severe cases.
257
What is the typical age group affected by HFMD?
A) <6 months
B) 1–5 years
C) 6–12 years
D) Adolescents
E) Adults
Answer: B
Explanation: HFMD commonly affects young children, especially those under 5 years of age.
258
Which clinical finding is most characteristic of HFMD?
A) Maculopapular rash over trunk
B) Vesicles on hands, feet, and oral mucosa
C) Petechiae over lower limbs
D) Purulent tonsillitis
E) Conjunctivitis
Answer: B
Explanation: The hallmark of HFMD is painful vesicles on hands, feet, and inside the mouth.
259
What is the mode of transmission of HFMD?
A) Bloodborne
B) Airborne
C) Fecal-oral and contact with secretions
D) Vector-borne
E) Perinatal
Answer: C
Explanation: HFMD spreads via fecal-oral route, respiratory droplets, and contact with vesicle fluid.
260
What is the incubation period of HFMD?
A) 1–2 days
B) 3–5 days
C) 6–10 days
D) 10–14 days
E) >14 days
Answer: B
Explanation: HFMD typically has an incubation period of 3–5 days after exposure.
261
What is the first symptom typically seen in HFMD?
A) Rash
B) Cough
C) Fever
D) Diarrhea
E) Photophobia
Answer: C
Explanation: Fever is usually the initial symptom, followed by sore throat and rash.
262
Which of the following is a complication of HFMD?
A) Myocarditis
B) Meningoencephalitis
C) Intussusception
D) Bronchiectasis
E) Hepatitis A
Answer: B
Explanation: Rare complications include encephalitis, especially with enterovirus 71.
263
How long is a child with HFMD considered contagious?
A) Until fever subsides
B) 24 hours after rash
C) Until all vesicles resolve
D) For several weeks in stool
E) Only during febrile period
Answer: D
Explanation: HFMD virus may be shed in stool for several weeks after recovery.
264
What is the mainstay of treatment for HFMD?
A) Antivirals
B) Steroids
C) Supportive care
D) Antibiotics
E) IVIG
Answer: C
Explanation: Management is supportive: antipyretics, hydration, and mouth pain relief.
265
What dietary advice is appropriate for a child with oral ulcers from HFMD?
A) Encourage citrus fruits
B) Give spicy food
C) Offer cold, bland liquids
D) Feed hard solid foods
E) Avoid all fluids
Answer: C
Explanation: Cold, soft, bland foods and fluids are best tolerated with oral lesions.
266
Which finding differentiates HFMD from herpangina?
A) Oral ulcers
B) Fever
C) Rash on palms/soles
D) Sore throat
E) Vesicles on tonsils
Answer: C
Explanation: HFMD has peripheral rash, which is absent in herpangina.
267
Which viral family does Coxsackievirus belong to?
A) Herpesviridae
B) Paramyxoviridae
C) Picornaviridae
D) Retroviridae
E) Flaviviridae
Answer: C
Explanation: Coxsackievirus is part of the Picornaviridae family.
268
When can a child with HFMD return to daycare?
A) After rash appears
B) When oral ulcers heal
C) Once afebrile and clinically improving
D) After 21 days
E) Immediately after diagnosis
Answer: C
Explanation: Children may return once they are fever-free and clinically improved, even if rash persists.
269
Which preventive measure is most effective for HFMD?
A) Insect repellents
B) Frequent handwashing
C) MMR vaccination
D) Quarantine for 3 weeks
E) Bed nets
Answer: B
Explanation: Hand hygiene is crucial in preventing the spread of HFMD.
270
Which symptom may precede rash in HFMD?
A) Diplopia
B) Irritability and decreased appetite
C) Polyuria
D) Productive cough
E) Jaundice
Answer: B
Explanation: Irritability and decreased appetite are common prodromal features.
271
What is the causative organism of typhoid fever?
A) Salmonella typhi
B) Shigella sonnei
C) E. coli
D) Vibrio cholerae
E) Salmonella enteritidis
Answer: A
Explanation: Typhoid fever is caused by the gram-negative bacterium Salmonella typhi.
272
What is the most common route of transmission for typhoid fever?
A) Airborne
B) Fecal-oral
C) Bloodborne
D) Sexual contact
E) Vertical transmission
Answer: B
Explanation: Typhoid is transmitted through ingestion of contaminated food or water (fecal-oral route).
273
Which symptom is most characteristic of pediatric typhoid fever?
A) Sudden high fever with chills
B) Step-ladder fever pattern
C) Intermittent fever with rigors
D) Rash on lower limbs
E) Cough and chest pain
Answer: B
Explanation: Step-ladder fever pattern (gradual rise) is classic in typhoid.
274
What is a typical gastrointestinal symptom of typhoid fever?
A) Watery diarrhea
B) Bloody diarrhea
C) Constipation followed by diarrhea
D) Severe vomiting
E) Tenesmus
Answer: C
Explanation: Constipation in early stages, followed by diarrhea, is common in typhoid.
275
Which skin manifestation may be seen in typhoid?
A) Erythema nodosum
B) Petechiae
C) Rose spots
D) Vesicular rash
E) Urticaria
Answer: C
Explanation: Rose spots are faint salmon-colored macules seen on the trunk in typhoid fever.
276
What is the gold standard for diagnosing typhoid fever?
A) Stool culture
B) Blood culture
C) Widal test
D) PCR
E) Serology
Answer: B
Explanation: Blood culture is the gold standard, especially within the first week of illness.
277
What is a limitation of the Widal test?
A) Requires lumbar puncture
B) Has low specificity
C) Detects DNA only
D) Cannot be used in children
E) Not widely available
Answer: B
Explanation: Widal has poor specificity and may cross-react with other infections.
278
Which antibiotic is first-line in areas with low resistance?
A) Ceftriaxone
B) Chloramphenicol
C) Azithromycin
D) Ampicillin
E) Ciprofloxacin
Answer: C
Explanation: Azithromycin is often used as first-line therapy where fluoroquinolone resistance is prevalent.
279
What is a complication of untreated typhoid fever?
A) Meningitis
B) Intestinal perforation
C) Endocarditis
D) Renal failure
E) Bronchiectasis
Answer: B
Explanation: Ileal perforation is a life-threatening complication of severe untreated typhoid.
280
Which investigation helps detect carrier status?
A) Urine culture
B) Nasopharyngeal swab
C) Stool culture
D) Antibody titer
E) Bone marrow biopsy
Answer: C
Explanation: Stool culture is useful for identifying chronic carriers of S. typhi.
281
What is the typical duration of antibiotic treatment in typhoid?
A) 3 days
B) 5 days
C) 7–14 days
D) 21 days
E) Until fever resolves
Answer: C
Explanation: 7–14 days of antibiotics is standard, depending on drug and severity.
282
Which organ is commonly enlarged in typhoid fever?
A) Lungs
B) Spleen
C) Brain
D) Kidneys
E) Pancreas
Answer: B
Explanation: Splenomegaly is frequently found on clinical examination in typhoid fever.
283
Which vaccine is recommended for typhoid prevention in children?
A) BCG
B) MMR
C) Typhoid Vi polysaccharide vaccine
D) DTaP
E) OPV
Answer: C
Explanation: The Vi polysaccharide vaccine is used for prevention in children >2 years.
284
What public health measure best prevents typhoid?
A) Wearing masks
B) Boiling drinking water
C) Use of insecticide-treated nets
D) Avoiding raw meat
E) Quarantine
Answer: B
Explanation: Boiling or treating drinking water is key to preventing fecal-oral transmission.
285
In chronic carriers, where is S. typhi most commonly found?
A) Brain
B) Spleen
C) Gallbladder
D) Lungs
E) Blood
Answer: C
Explanation: The gallbladder is the primary reservoir in chronic carriers of typhoid.
286
What is the causative agent of rabies?
A) DNA virus
B) Paramyxovirus
C) Lyssavirus (Rhabdoviridae)
D) Arenavirus
E) Flavivirus
Answer: C
Explanation: Rabies is caused by the Lyssavirus, belonging to the Rhabdoviridae family.
287
How is rabies most commonly transmitted to children?
A) Blood transfusion
B) Mosquito bite
C) Dog bite
D) Contaminated food
E) Airborne droplets
Answer: C
Explanation: Dog bites are the most common source of rabies transmission worldwide.
288
Which of the following is an early symptom of rabies?
A) Paralysis
B) Seizures
C) Fever and paresthesia at bite site
D) Hematuria
E) Diarrhea
Answer: C
Explanation: Early symptoms include fever, malaise, and tingling at the bite site.
289
What is the incubation period of rabies?
A) 1–2 days
B) 5–10 days
C) 1–3 weeks
D) 1–3 months
E) Over 1 year
Answer: D
Explanation: The average incubation period is 1–3 months, but it can vary widely.
290
Which type of rabies is more common?
A) Paralytic (dumb) rabies
B) Encephalitic (furious) rabies
C) Neonatal rabies
D) Asymptomatic rabies
E) Localized rabies
Answer: B
Explanation: Furious rabies is more common and is characterized by hyperactivity and hydrophobia.
291
Which symptom is pathognomonic of rabies?
A) Rash
B) Diarrhea
C) Hydrophobia
D) Tinnitus
E) Bradycardia
Answer: C
Explanation: Hydrophobia (fear of water) is highly characteristic of rabies.
292
What is the outcome of symptomatic rabies infection?
A) Full recovery in most cases
B) Recovery with treatment
C) Death is almost certain
D) Only 10% mortality
E) Remission
Answer: C
Explanation: Once symptoms appear, rabies is nearly always fatal.
293
Which test confirms rabies ante-mortem?
A) Widal test
B) Serum IgG
C) RT-PCR from saliva or nuchal skin biopsy
D) Urine culture
E) CSF glucose
Answer: C
Explanation: PCR testing from saliva or skin biopsy can detect viral RNA before death.
294
Which of the following is part of rabies post-exposure prophylaxis (PEP)?
A) Tetanus toxoid
B) Rabies vaccine only
C) Rabies vaccine + rabies immunoglobulin (RIG)
D) Antibiotics + vaccine
E) IVIG only
Answer: C
Explanation: PEP includes thorough wound cleaning, rabies vaccine, and RIG for Category III exposure.
295
When should rabies immunoglobulin be given?
A) 1 week after exposure
B) Only in mild cases
C) Immediately with the first vaccine dose
D) After all vaccine doses
E) Not given to children
Answer: C
Explanation: RIG should be given as early as possible, ideally with the first dose of vaccine.
296
What is the schedule for intramuscular rabies vaccine (Essen regimen)?
A) Days 0 and 7
B) Days 0, 3, 7, 14, and 28
C) Days 0 and 28 only
D) Once weekly for 6 weeks
E) Monthly for 3 months
Answer: B
Explanation: The Essen regimen consists of 5 doses on days 0, 3, 7, 14, and 28.
297
Which wound is considered Category III exposure?
A) Touching animal
B) Licking intact skin
C) Superficial scratch without bleeding
D) Transdermal bite or scratch
E) Feeding an animal
Answer: D
Explanation: Category III exposure includes transdermal bites or scratches and mucosal exposure to saliva.
298
Which animals are common rabies reservoirs in developing countries?
A) Bats
B) Rats
C) Domestic cats
D) Dogs
E) Parrots
Answer: D
Explanation: Dogs are the major reservoir of rabies in many developing countries.
299
Why is thorough wound washing essential in rabies prevention?
A) It cools the wound
B) It disinfects bacteria
C) It reduces viral load at the site
D) It avoids pain
E) It is part of antibiotic prophylaxis
Answer: C
Explanation: Immediate wound cleaning reduces viral load and helps prevent infection.
300
What is the status of rabies in terms of public health?
A) Rare disease
B) Negligible threat
C) 100% preventable zoonotic disease
D) Non-reportable disease
E) Endemic to cold climates
Answer: C
Explanation: Rabies is a 100% preventable zoonotic disease with timely prophylaxis.
301
What is the causative organism of tetanus?
A) Clostridium difficile
B) Clostridium botulinum
C) Clostridium tetani
D) Bacillus anthracis
E) Listeria monocytogenes
Answer: C
Explanation: Tetanus is caused by Clostridium tetani, a gram-positive, spore-forming anaerobic bacillus.
302
What is the neurotoxin responsible for symptoms in tetanus?
A) Botulinum toxin
B) Tetanospasmin
C) Endotoxin
D) Exotoxin A
E) Streptolysin O
Answer: B
Explanation: Tetanospasmin is the potent neurotoxin produced by C. tetani, leading to muscle rigidity.
303
Which symptom is most characteristic of tetanus?
A) Flaccid paralysis
B) Hypotonia
C) Trismus (lockjaw)
D) Rash
E) Diarrhea
Answer: C
Explanation: Trismus (lockjaw) is a hallmark symptom of generalized tetanus.
304
How does tetanospasmin affect the nervous system?
A) Inhibits acetylcholine release
B) Blocks GABA and glycine release
C) Causes demyelination
D) Increases dopamine production
E) Activates NMDA receptors
Answer: B
Explanation: The toxin blocks inhibitory neurotransmitters (GABA and glycine), causing rigidity and spasms.
305
What is neonatal tetanus usually associated with?
A) Breastfeeding
B) Contaminated umbilical cord care
C) Formula feeding
D) Iron deficiency
E) Fever post-vaccine
Answer: B
Explanation: Neonatal tetanus often results from unhygienic handling of the umbilical cord.
306
What is the incubation period of tetanus?
A) 1–2 days
B) 3–5 days
C) 5–10 days
D) 1–2 weeks
E) 3–21 days
Answer: E
Explanation: The incubation period is typically 3–21 days, but symptoms may appear earlier in severe cases.
307
Which of the following is a type of tetanus?
A) Latent
B) Spastic
C) Generalized
D) Migratory
E) Segmental
Answer: C
Explanation: Tetanus is classified into generalized, localized, cephalic, and neonatal forms.
308
What is the mainstay of treatment in tetanus?
A) Antibiotics only
B) Antitoxin + supportive care
C) NSAIDs + hydration
D) Surgery
E) Vaccination alone
Answer: B
Explanation: Treatment includes tetanus immunoglobulin (TIG), antibiotics, and supportive care including sedation and ventilation if needed.
309
Which antibiotic is commonly used in tetanus treatment?
A) Amoxicillin
B) Vancomycin
C) Metronidazole
D) Gentamicin
E) Azithromycin
Answer: C
Explanation: Metronidazole is preferred for its anaerobic coverage and better outcomes compared to penicillin.
310
What is the role of tetanus toxoid in management?
A) Treats active disease
B) For prophylaxis only
C) Prevents recurrence
D) Neutralizes circulating toxin
E) Causes immunity immediately
Answer: B
Explanation: Tetanus toxoid is used for prophylaxis; it does not treat active disease.
311
What is the vaccine schedule for tetanus in children?
A) At birth only
B) 2, 4, 6, and 18 months + 4–6 years boosters
C) Monthly until 1 year
D) Every 2 years
E) Yearly boosters
Answer: B
Explanation: Tetanus vaccine is part of DTaP at 2, 4, 6, and 18 months, with boosters at 4–6 years.
312
What is the recommendation after a dirty wound in an incompletely immunized child?
A) Nothing
B) Tetanus toxoid only
C) TIG only
D) Both TIG and tetanus toxoid
E) Antibiotics alone
Answer: D
Explanation: Children with uncertain or incomplete immunization require both TIG and tetanus vaccine.
313
What complication is feared in tetanus?
A) Coma
B) Intestinal obstruction
C) Respiratory failure due to muscle spasms
D) Hepatitis
E) Nephrotic syndrome
Answer: C
Explanation: Laryngospasm and respiratory muscle rigidity can lead to respiratory failure.
314
What is cephalic tetanus?
A) Tetanus localized to spine
B) Involves cranial nerves, often facial nerve
C) In neonates only
D) Found only after head injury
E) Benign form of tetanus
Answer: B
Explanation: Cephalic tetanus involves cranial nerves, especially facial nerve, and may follow head wounds.
315
What is the prognosis of untreated generalized tetanus?
A) Excellent
B) 50% recovery
C) High mortality
D) Self-limiting
E) Reversible with hydration
Answer: C
Explanation: Without appropriate care, generalized tetanus has high mortality, especially in neonates and children.
