Infection

Question 1

Why are newborn infants more vulnerable to infections compared to older children?

Answer 1

Newborn infants are more vulnerable to infections due to their immature immune systems, which are not yet fully developed to effectively fight off pathogens.

Question 2

How can newborn infants acquire infections?

Answer 2

Newborn infants can acquire infections from various sources, including the mother during pregnancy, labor, delivery, or breastfeeding. Infections can also be acquired from the nursery or home environment after birth, through exposure to pathogens.

Question 3

Why are preterm infants more prone to serious complications from infections?

Answer 3

Preterm infants are more vulnerable to serious complications from infections due to their immature immune systems and underdeveloped organs, which may not be able to cope with the effects of the infection as effectively as those of full-term infants.

Question 4

Defense Mechanism: specific antibodies

Answer 4

1. humoral antibodies
2. cell mediated immunity
3. inflammatory reaction

Question 5

Defense Mechanism: General factors

Answer 5

1. antenatal
2. postnatal
3. nursery care

Question 6

Which type of antibody is transferred across the placenta, especially in the last trimester, to protect the infant against specific infections?

Answer 6

IgG antibodies are transferred across the placenta, especially in the last trimester of pregnancy. This passive immunity protects the infant, particularly the term infant, against specific infections to which the mother has been immunized.

Question 7

How long does passive immunity provided by IgG antibodies transferred across the placenta typically last in infants?

Answer 7

Passive immunity provided by IgG antibodies transferred across the placenta typically wanes after four to six months of age. However, in some cases, it may persist up to 9 months, as seen with infections like measles.

Question 8

Do IgM and IgA antibodies cross the placenta?

Answer 8

No, neither IgM nor IgA antibodies cross the placenta. These antibodies are normally only produced by the infant after birth.

Question 9

Under what circumstances can a fetus produce IgM antibodies?

Answer 9

The fetus can produce IgM antibodies in response to an intrauterine infection, such as congenital syphilis.

Question 10

Why is cell-mediated immunity compromised in newborn infants?

Answer 10

Cell-mediated immunity is compromised in newborn infants because their lymphocytes have not yet been exposed to antigens, and thus do not function effectively.

Question 11

How does the inflammatory response differ in newborns compared to older individuals?

Answer 11

In newborns, the inflammatory response is poor. Phagocytosis of bacteria by leukocytes is inefficient due to reduced opsonins (such as complement) and delayed chemotaxis.

Question 12

Why are newborn infants, especially preterm infants, at high risk of infections?

Answer 12

Newborn infants, especially preterm infants, are at high risk of infections due to their immature and inexperienced immune system. The compromised inflammatory response and inefficient phagocytosis increase susceptibility to infections.

Question 13

Which organisms can pass through the placenta during pregnancy, despite its filtering function?

Answer 13

While the placenta filters out most organisms, some can still pass through, including the Rubella virus, HIV, Toxoplasma, CMV (Cytomegalovirus), and Treponema pallidum (syphilis).

Question 14

What substances are present in amniotic fluid to reduce the risk of bacterial infection?

Answer 14

Amniotic fluid contains lysozymes and other antibacterial agents. These substances help to reduce the risk of bacterial infection in the prenatal environment.

Question 15

What components in breast milk help protect infants against infections?

Answer 15

Breast milk contains various components such as IgG, IgM, IgA, lymphocytes, macrophages, and lysozymes. Lactoferrin and transferrin present in breast milk specifically protect against Gram-negative organisms.

Question 16

How does breastfeeding influence the microbiota in infants?

Answer 16

Breastfeeding promotes the growth of beneficial bacteria like Lactobacilli while inhibiting the growth of harmful bacteria like E. coli, contributing to a healthier gut microbiota in infants.

Question 17

What measures can be taken in nursery care to prevent infections?

Answer 17

In nursery care, infection prevention can be achieved through practices such as hand-washing, good skin, cord, and eye care. Kangaroo mother care (KMC) also helps by colonizing the infant with maternal flora, while hand-washing, breast milk feeding, and KMC combined can effectively prevent many cases of nosocomial infection in the nursery.

Question 18

What are the sources of infections during the antenatal period?

Answer 18

Infections during the antenatal period can occur via transplacental spread, involving organisms such as syphilis, HIV, Rubella, CMV, and Varicella. Additionally, ascending spread from the cervix can cause bacterial chorioamnionitis.

Question 19

Which infections can be transmitted during the intrapartum period?

Answer 19

During labor and delivery, infections such as HIV, Herpes, Group B Streptococci, Gonococci, Candida, Chlamydia, and Hepatitis B pose a risk, with increased risk associated with prolonged labor.

Question 20

What are the sources of infections in the postnatal period?

Answer 20

In the postnatal period, infections can occur through cross-infection via contaminated hands, feeds, or inhalation. Additionally, unsterile procedures, intubation, and the presence of long lines can contribute to the spread of infections. Breast milk can transmit HIV and CMV.

Question 21

What infection can be acquired through contact at home?

Answer 21

What infection can be acquired through contact at home?

Question 22

What is the definition of congenital infection?

Answer 22

Congenital infection refers to the infection of the fetus at any time during pregnancy, excluding the last 5 days before birth, which is considered perinatal infection.

Question 23

What does the acronym TORCHES stand for in the context of congenital infections?

Answer 23

The acronym TORCHES stands for Toxoplasmosis, Other (including TB, malaria, listeriosis, etc.), Rubella, Cytomegalovirus, Herpes simplex virus, and Syphilis. It serves as a mnemonic to remind healthcare providers of potential causes of congenital infections. However, it’s worth noting that some of these organisms, like herpes, rarely cause true congenital infections, while others may be geographically concentrated, such as toxoplasmosis.

Question 24

What are some clinical features commonly observed in infants with congenital infection

Answer 24

Infants with congenital infection often present with widespread disease as the organisms typically enter the bloodstream via the umbilical vessels. Clinically obvious features may include growth restriction, hepatosplenomegaly (HSM), pneumonitis, petechiae, jaundice (conjugated), or microcephaly.

Question 25

How can the placenta assist in diagnosing congenital infection?

Answer 25

The placenta is usually infected in cases of congenital infection and can serve as a valuable organ for determining the diagnosis. Examination of the placenta can provide important clues and help confirm the presence of infection, aiding in the diagnosis and management of the condition.

Question 26

How should syphilis screening be conducted in pregnant women?

Answer 26

All pregnant women should be screened for syphilis at their booking visit using a TPHA (Treponema Pallidum Haemagglutination Assay). If the TPHA is positive, a VDRL (Venereal Disease Research Laboratory) or RPR (Rapid Plasma Reagin) test should be performed to distinguish present from past infection.

Question 27

What diagnostic criteria suggest a high likelihood of syphilis infection during pregnancy?

Answer 27

A VDRL or RPR titre of 1:16 or above is highly suggestive of syphilis infection during pregnancy.

Question 28

What are the potential effects of syphilis on pregnancy

Answer 28

Syphilis can affect the placenta and fetus, leading to adverse outcomes such as first-trimester abortion, stillbirth, clinically infected infant at birth, or delayed onset of syphilis signs in apparently normal infants.

Question 29

Treatment of syphilis

Answer 29

Infected mothers should receive treatment with 2.4 million units of benzathine penicillin intramuscularly every week for three weeks to prevent transmission to the fetus and improve maternal health.

Question 30

Clinical signs of syphilis

Answer 30

• Heavy, pale placenta.
• Rash including on palms and soles. May be peeling.
• Hepatosplenomegaly (90%).
• Jaundice (conjugated), pallor or purpura.
• Oedema.
• Respiratory distress due to syphilitic pneumonia.
• X-ray examination of the long bones may show metaphysitis, especially around
  the knee.
• The infant’s TPHA and VDRL/RPR is positive, whether infected or not, as the
  maternal antibodies cross the placenta. If the infant titre is higher than the
  maternal titre this suggests infection.

Question 32

What is the recommended treatment for infants presenting with clinical signs of syphilis?

Answer 32

Infants with clinical signs of syphilis should be treated with penicillin G, administered intravenously at a dose of 100,000 units every 12 hours for a duration of 10 days.

Question 33

How should infants born to mothers with untreated or incompletely treated syphilis be treated if they are clinically normal?

Answer 33

Infants born to mothers with untreated or incompletely treated syphilis, but who are clinically normal, should receive a single dose of 50,000 units/kg benzathine penicillin administered intramuscularly.

Question 34

What actions should be taken regarding symptomatic congenital syphilis?

Answer 34

Symptomatic congenital syphilis is a notifiable condition, meaning it must be reported to health authorities. Additionally, partners of mothers with congenital syphilis should also be treated to prevent further transmission of the infection.

Question 35

What are the characteristics of congenital cytomegalovirus (CMV) infection?

Answer 35

Congenital CMV infection is the most common congenital infection worldwide and typically occurs when there is primary infection in the mother.

Question 36

Complications of congenital CMV

Answer 36

It can lead to various complications, including microcephaly, chorio-retinitis, thrombocytopenia, and deafness.

Question 37

How should symptomatic neurological CMV be treated?

Answer 37

Symptomatic neurological CMV should be treated with ganciclovir or valganciclovir for a minimum of 6 weeks. This treatment is aimed at improving hearing and neurological outcomes in affected infants.

Question 38

How is congenital CMV infection confirmed in infants?

Answer 38

Congenital CMV infection is confirmed by sending urine samples for PCR (polymerase chain reaction) testing within the first 3 weeks of life. This diagnostic test helps identify the presence of CMV DNA in the urine, confirming the infection in newborns.

Question 39

What are the implications for the fetus if rubella (German measles) is contracted during the first trimester of pregnancy?

Answer 39

Rubella contracted during the first trimester of pregnancy can have marked implications for the fetus. These can include cataracts, CNS (central nervous system) damage, deafness, cardiac malformations (especially patent ductus arteriosus), and a characteristic ‘blueberry muffin’ rash.

Question 40

Is there a specific treatment for congenital rubella?

Answer 40

There is no specific treatment for congenital rubella. However, it’s important to note that the infant is infectious, and susceptible staff should take precautions to prevent transmission. Congenital rubella is a vaccine-preventable disease.

Question 41

How can congenital rubella infection be confirmed in infants?

Answer 41

Congenital rubella infection can be confirmed by sending urine samples for PCR (polymerase chain reaction) testing or by detecting IgM antibodies in the infant. These tests help identify the presence of rubella virus or specific antibodies, confirming the infection in newborns.

Question 42

How common is congenital tuberculosis?

Answer 42

Congenital tuberculosis is relatively rare.

Question 43

How is tuberculosis commonly transmitted to infants?

Answer 43

The more common scenario is that the infant is well but may be in close proximity to a mother or family member who may have tuberculosis.

Question 44

What prophylactic measure should be taken for infants exposed to tuberculosis, especially if the mother is sputum positive or recently diagnosed?

Answer 44

If the mother is sputum positive or recently diagnosed with tuberculosis, the infant should be placed on isoniazid (INH) prophylaxis. However, it’s important to remember to delay the BCG vaccination until the infant is no longer on INH.

Question 45

Name the types of congenita infections

Answer 45

TORCHES

Question 46

Perinatal infection definition

Answer 46

Perinatal infections are a group of infections caused by bacteria, viruses, or parasites that are transmitted from a mother to her baby during pregnancy or childbirth

Question 47

Types of perinatal infections

Answer 47

varicella
hepatitis B
herpes

Question 48

What is the risk of varicella (chickenpox) affecting the fetus during pregnancy?

Answer 48

Varicella very rarely affects the fetus during pregnancy.

Question 49

When is the vulnerable period for infants at higher risk of mortality and morbidity due to varicella?

Answer 49

There is a vulnerable week in which the infant is at higher risk of mortality (up to 30%) and morbidity if the mother develops a chickenpox rash from 5 days before delivery till 2 days afterwards.

Question 50

What should be done for infants who have been exposed to maternal varicella infection during the vulnerable period?

Answer 50

Infants exposed to maternal varicella infection during the vulnerable period should receive VZIG (varicella zoster immunoglobulins). This helps ameliorate the disease process by providing passive immunity against the virus.

Question 51

How does the hepatitis B virus typically infect infants?

Answer 51

The hepatitis B virus does not cross the placenta but may infect the infant during delivery, particularly if the mother is hepatitis B surface antigen positive.

Question 52

What is the recommended course of action for infants born to hepatitis B surface antigen positive mothers?

Answer 52

f the mother is hepatitis B surface antigen positive, the infant should receive the hepatitis B vaccine within 24 hours of birth. Additionally, if the mother is hepatitis B e antigen positive, or if this information is unknown, the infant should also receive passive antibodies (Hebagam) within 72 hours of birth.

Question 53

What are the potential long-term consequences for infants infected with hepatitis B virus?

Answer 53

Infected infants usually become chronic hepatitis B carriers and may develop serious liver complications, such as cirrhosis or hepatocellular carcinoma, decades later in life.

Question 54

How is herpes typically transmitted to infants?

Answer 54

Herpes is usually a perinatal, not congenital, infection. The infant is usually infected during the birth process when they come into contact with infected vesicles.

Question 55

When is the greatest risk to the infant in terms of herpes infection from the mother?

Answer 55

The greatest risk to the infant is when the mother has a primary herpes infection, rather than reactivation or reinfection, due to the lack of antibodies passed to the infant.

Question 56

What are the clinical presentations of herpes infection in infants, and how is it treated?

Answer 56

Infants infected with herpes usually become unwell 5-10 days after birth and may present with localized skin/eye vesicles or, more seriously, with CNS or disseminated disease. Treatment typically involves intravenous acyclovir.

Question 57

Common minor post natal infections

Answer 57

1. conjunctivitis
2. non- gonococcal conjunctivitis
3. skin infections
4. thrush (moniliasis)
5. umbilical infection (omphalitis)
6. septicemia

Question 58

What is gonococcal conjunctivitis, and when does it usually present in newborns?

Answer 58

Gonococcal conjunctivitis is a serious acute infection that typically presents in the first few days after delivery. It can lead to corneal damage and blindness if left untreated.

Question 59

What are the clinical features of gonococcal conjunctivitis, and how is it diagnosed?

Answer 59

Gonococcal conjunctivitis often presents with rapid onset of red, swollen conjunctiva and copious purulent discharge. Diagnosis can be quickly made with a Gram stain on a smear of pus, revealing Gram-negative diplococci in leukocytes.

Question 60

How is gonococcal conjunctivitis treated in newborns, and how can it be prevented?

Answer 60

Treatment involves repeated irrigation with normal saline to keep the eye free of pus, along with a single intramuscular dose of ceftriaxone (50 mg/kg). It’s important to also treat the mother and have her VDRL checked. Neonatal gonococcal conjunctivitis is notifiable. Additionally, gonococcal conjunctivitis can be prevented by routinely applying chloramphenicol eye ointment to both eyes after delivery.

Question 61

What is the typical treatment regimen for non-gonococcal conjunctivitis acquired after delivery?

Answer 61

For most infections acquired after delivery, chloramphenicol ointment or drops applied every 8 hours for 5 days is usually sufficient.

Question 62

What should be done if Chlamydia infection is suspected in non-gonococcal conjunctivitis, or if inflammation recurs after chloramphenicol therapy?

Answer 62

If Chlamydia infection is suspected or if inflammation recurs after chloramphenicol therapy, tetracycline or erythromycin ointment should be used. Proven Chlamydia infections should also be treated with oral erythromycin at a dose of 10 mg/kg every 6 hours for 10 days.

Question 63

What are the common causes and presentations of skin infections?

Answer 63

What are the common causes and presentations of skin infections?

Question 64

How are skin infections diagnosed and treated?

Answer 64

he diagnosis of skin infections is made through Gram stain and culture, which determine the form of treatment. Mild superficial infections may be treated with chlorhexidine (Hibiscrub), while abscesses require incision and drainage. More severe infections, such as cellulitis, require systemic antibiotic therapy.

Question 65

What are some differential diagnoses for clear vesicles on the skin?

Answer 65

Clear vesicles on the skin may suggest a herpes infection. However, small vesicles may also be due to conditions such as miliaria crystallinum (sweating on the forehead usually) or pustular melanosis.

Question 66

What causes moniliasis (thrush), and which areas of the body does it commonly affect?

Answer 66

Moniliasis is caused by the fungus Candida and commonly affects the mouth or the nappy area. The source is usually the mother’s vagina or nipples, or contaminated hands, bottles, etc.

Question 67

What are the clinical features of oral thrush?

Answer 67

In oral thrush, small white patches are found on the tongue and may spread to the inside of the cheeks and lips. These white plaques resemble curds of milk but are difficult to dislodge. The underlying mucosa is red and inflamed, and sucking is often painful

Question 68

How is moniliasis (thrush) treated?

Answer 68

Moniliasis is typically treated with mycostatin suspension (Nystatin) or miconazole (Daktarin) gel applied after each feed for 5 days. If the mother is breastfeeding, mycostatin should also be applied to the nipples.

Question 69

What are the common causes of umbilical infection (omphalitis), and why is it considered potentially serious?

Answer 69

Umbilical infection (omphalitis) is usually due to Staphylococci or Coliforms and is potentially serious as it may result in peritonitis or septicemia.

Question 70

What are the clinical signs of umbilical infection?

Answer 70

In mild infections, the cord is moist and smells offensive, with a red flare that may extend onto the skin of the abdominal wall. A purulent or bloody discharge may also be present. Severe infections present with redness and edema of the anterior abdominal wall.

Question 71

How can umbilical infection (omphalitis) be largely prevented, and what complications may arise?

Answer 71

Umbilical infection can be largely prevented by routinely cleaning all cords twice a day. Complications of omphalitis may include tetanus, making prevention through cleanliness and hygiene measures crucial.

Question 72

When can infection leading to septicemia begin, and what are the common organisms involved?

Answer 72

Infection leading to septicemia may begin before or after birth. Common organisms include Gram-negative organisms, especially E. coli and Klebsiella, as well as group B haemolytic Streptococci (Streptococcus agalactiae).

Question 73

When do hospital-acquired infections typically present in the context of septicemia?

Answer 73

Hospital-acquired infections in the context of septicemia usually present after 72 hours of age.

Question 74

Clinical signs of septicemia

Answer 74

non-specific e.g. poor feeding, poor weight gain, lethargy,
hypothermia, jaundice, pallor, apnoea, abdominal distension. The temperature may be
raised but is more often normal or sub-normal. It is easy to miss the diagnosis.

Question 75

How to diagnosis septicaemia

Answer 75

Confirmed on blood culture. CRP may be normal initially but then
increases above 10 mg/l.

Question 76

Complications of septicaemia

Answer 76

meningitis, pneumonia, metabolic disturbances including acidosis,
hypoglycaemia, disseminated intravascular coagulation.

Question 77

What antibiotics are typically prescribed for early onset sepsis (<72 hours)?

Answer 77

For early onset sepsis, ampicillin and gentamicin are usually prescribed as they provide coverage against both Gram-positive and Gram-negative organisms typically encountered.

Question 78

What antibiotics are commonly used to treat late onset sepsis?

Answer 78

Late onset sepsis is usually treated with aminoglycosides (e.g., amikacin) or carbapenems (e.g., meropenem), which offer broad-spectrum coverage against a range of pathogens.

Question 79

When is vancomycin added to the antibiotic regimen, and how is treatment monitored?

Answer 79

Vancomycin may be added if Staphylococcus is suspected. Treatment is monitored by reviewing blood culture and C-reactive protein (CRP) levels after 48 hours of treatment. Antibiotics can typically be stopped at 48 hours if the patient is clinically well, blood culture is negative, and CRP levels are normal (<10).

Question 80

How does meningitis typically present?

Answer 80

Meningitis usually presents as septicaemia. Later symptoms may include local signs such as a full tense fontanelle, squint, convulsions, increased tone, or coma. Neck stiffness is unusual but may be present in some cases. Meningitis may also complicate an open neural tube defect.

Question 81

How is meningitis diagnosed?

Answer 81

Meningitis is confirmed by lumbar puncture, which allows for the analysis of cerebrospinal fluid.

Question 82

What is the recommended treatment for meningitis?

Answer 82

The treatment for meningitis typically involves a prolonged course of antibiotics for 14-21 days to effectively clear the infection.