Infectious Disease

Question 1

Term infant, healthy mom, uncomplicated pregnancy. Normal growth parameters. Platelet count of 60. Most likely cause?

1. Toxoplasmosis
2. Rubella
3. CMV
4. Syphilis
5. HIV

Answer 1

3. CMV

Question 2

You receive a report of a positive CMV test on an infant who is now 2 months old. Thrombocytopenia at birth, now resolved. He is asymptomatic. What is the most important thing to do now?

1. MRI head
2. Ultrasound head
3. Hearing screen
4. Initiate treatment with IV ganciclovir
5. Initiate treatment with PO valganciclovir

Answer 2

3. Hearing screen

Question 3

Newborn with IUGR, failed hearing screen, positive CMV PCR on urine. What to do?

1. Reassure and follow-up in 6 months
2. Ganciclovir for 2 weeks
3. Valganciclovir for 4 weeks
4. Valganciclovir for 6 months

Answer 3

4. Valganciclovir for 6 months

Question 4

Newborn with maculopapular rash, microcephaly, chorioretinitis, hepatosplenomegaly, bony changes. Most likely diagnosis?

1. Toxoplasmosis
2. Rubella
3. Parvovirus
4. Syphilis
5. HIV

Answer 4

4. Syphilis

Question 5

Mom diagnosed with syphilis week 32 of pregnancy, RPR 1:128. Given single dose IM penicillin after which RPR drops to 1:64. Infant has normal physical exam; RPR 1:32. Management?

1. No treatment as mom was appropriately treated
2. Full workup including LP; give 10 days of IV penicillin regardless of workup findings
3. Full workup including LP; 10 days of IV penicillin if workup abnormal
4. Full workup including LP; single dose IM penicillin if workup abnormal

Answer 5

2. Full workup including LP; give 10 days of IV penicillin regardless of workup findings

Question 6

Well appearing newborn infant of mother whose husband resided in Brazil until 2 months prior to conception. What testing on baby?

1. Zika PCR in blood and urine and head ultrasound
2. Brain MRI
3. Zika serology
4. No testing of baby

Answer 6

4. No testing of baby

Question 7

37 week newborn, GBS negative mother. Membranes ruptured x20 hours before delivery. Intrapartum fever. Ampicillin 5 hours prior to delivery. Newborn appears well. Management?

1. Routine care, discharge at 24 hours
2. Observe closely with vital signs every 3-4 hours for 24-48 hrs; consider CBC 4 hours after birth
3. Observe closely with vital signs every 3-4 hours for 48 hrs; do CBC and blood culture at birth
4. Investigate promptly, full sepsis workup, empiric antibiotic coverage

Answer 7

2. Observe closely with vital signs every 3-4 hours for 24-48 hrs; consider CBC 4 hours after birth

Question 8

7-day-old infant with small vesicular lesion; Systemically well; normal physical exam. You suspect HSV. Management?

1. Lesion scraping for HSV; if positive, treat with IV acyclovir
2. Lesion scraping for HSV; initiate acyclovir; D/C acyclovir if PCR negative
3. Full sepsis workup; HSV PCR of lesion scraping, blood and CSF; initiate IV acyclovir
4. Lesion scraping + mouth/eye swabs for HSV PCR; initiate IV acyclovir; D/C acyclovir if PCR negative

Answer 8

3. Full sepsis workup; HSV PCR of lesion scraping, blood and CSF; initiate IV acyclovir

Question 9

32-year-old G1L0 woman with recurrent genital HSV-2; lesions noted postpartum. Well appearing child, born vaginally at term. Management?

1. Surface swabs, blood & CSF for HSV PCR; start IV acyclovir
2. Surface swabs for HSV PCR; no treatment pending PCR results
3. Surface swabs for HSV PCR; IV acyclovir pending PCR results
4. No need for swabs as recurrent disease; monitor clinically, workup and treat if symptomatic

Answer 9

2. Surface swabs for HSV PCR; no treatment pending PCR results

Question 10

Four-year-old with few days of cough, respiratory symptoms, fever. O2 saturation 95% on room air. CXR shows LLL consolidation. Best antibiotic?

1. Ceftriaxone
2. Ceftriaxone + azithromycin
3. Azithromycin
4. Amoxicillin
5. Ceftriaxone + vancomycin

Answer 10

4. Amoxicillin

Question 11

Four-year-old with temperature of 400C, tachypneic, toxic appearing. O2 saturation 96% with FiO2 of 45%. What treatment do you start?

1. Ceftriaxone + vancomycin
2. Ceftriaxone + azithromycin
3. Ampicillin
4. Ceftriaxone
5. Ampicillin + vancomycin

Answer 11

1. Ceftriaxone + vancomycin
2. Ceftriaxone

(both correct)

Question 12

Nine-week-old infant with fever 39.5C. CBC shows WBC 4.5 (60% neutrophils), serum glucose 4.5 mmol/L. CSF 400 RBC, 100 WBC, glucose 1.5, protein normal. Gram stain negative. Treatment?

1. IV ampicillin and cefotaxime
2. IV ceftriaxone and vancomycin
3. IV cefotaxime and acyclovir
4. IV acyclovir

Answer 12

2. IV ceftriaxone and vancomycin

Question 13

Three year old child with fever and limp for one day. Tender over distal femur. Which is most sensitive for diagnosis of osteomyelitis?

1. Plain x-ray
2. Bone scan
3. Magnetic resonance imaging
4. Needle aspiration of affected site

Answer 13

3. Magnetic resonance imaging

Question 14

Three year old with abscess on buttock (2 cm); no surrounding erythema and no fever. Sibling had similar lesion recently. Management?

1. Cephalexin for 10 days; incision & drainage if fails to respond
2. Cotrimoxazole for 10 days ; incision & drainage if fails to respond
3. Incision & drainage, no antibiotics
4. Incision & drainage; cephalexin and cotrimoxazole pending culture results

Answer 14

3. Incision & drainage, no antibiotics

Question 15

7-year-old chicken pox x5 days. New fever last night. Refuses to weight bear. Vital signs stable. Minimal erythema, but indurated and exquisitely tender foot. Blood culture growing S. pyogenes. Management?

1. IV penicillin + clindamycin and surgery consult
2. IV ceftriaxone + vancomycin and MRI
3. IV cefazolin, MRI and surgery consult
4. IV vancomycin, MRI and surgery consult

Answer 15

1. IV penicillin + clindamycin and surgery consult

Question 16

4 year old boy with sickle cell disease is admitted with fever. He is hypotensive, grunting and is being transferred to the ICU. Best management?

1. Ceftriaxone
2. Ceftriaxone plus vancomycin
3. Vancomycin plus gentamicin
4. Cefuroxime plus vancomycin
5. Piperacillin-tazobactam

Answer 16

2. Ceftriaxone plus vancomycin

Question 17

10 year old with unilateral swollen cervical nodes and ipsilateral conjunctivitis. No fever or atypical lymphocytes. Most likely cause

1. Staphylococcus aureus
2. Toxoplasma gondii
3. Bartonella henselae
4. EBV
5. Mycobacterium tuberculosis

Answer 17

3. Bartonella henselae

Question 18

Four year old with chronically draining cervical node. Most likely bug:

1. Staphylococcus aureus
2. Atypical mycobacterium
3. Bartonella henselae
4. Tuberculosis
5. EBV

Answer 18

2. Atypical mycobacterium

Question 19

Five year old who had a tick bite 2-3 weeks ago has fever, malaise and a 5 cm single target lesion rash. Which is correct?

1. Heart block occurs in 10% of untreated children
2. The child should be treated with IV ceftriaxone
3. Can be transmitted to humans by dog ticks
4. Erythema migrans occurs in all untreated cases
5. Facial nerve palsy in the most common neurologic manifestation

Answer 19

5. Facial nerve palsy in the most common neurologic manifestation

Question 20

6-year-old returned from summer trip to Nova Scotia with family. Erythematous rash with red center and concentric ring around it. Also has low grade fever. Management?

1. Start amoxicillin now
2. Start doxycycline now
3. Start amoxicillin if serology +ve for Borrelia burgdorferi
4. Start doxycycline if serology +ve for Borrelia burgdorferi

Answer 20

1. Start amoxicillin now
2. Start doxycycline now

(both correct)

Question 21

Child with unilateral facial weakness, and vesicles in ear canal. Best management

1. Acyclovir
2. Steroids
3. Acyclovir + steroids
4. No effective treatment

Answer 21

3. Acyclovir + steroids

Question 22

Which is the most common manifestation of west Nile virus infection

1. Non-specific febrile illness
2. Maculopapular rash
3. Asymptomatic
4. Meningitis
5. Acute flaccid paralysis

Answer 22

3. Asymptomatic

Question 23

15 yo boy develops varicella. Two days later he become tachypneic and has difficulty breathing. Admitted to hospital for oxygen supplementation. What is the most likely cause of his presentation?

1. Myocarditis
2. Pulmonary embolus
3. VZV pneumonia
4. Sepsis
5. S. aureus pneumonia

Answer 23

3. VZV pneumonia

Question 24

16 year old girl is sexually active (single partner). She in on the birth control pill and both she and boyfriend are well. You recommend

1. No STI testing needed as both asymptomatic
2. NAAT on first catch urine for C. trachomatis and N. gonorrhoeae, HIV serology, syphilis serology
3. Serology for C. trachomatis, N. gonorrhoeae, HIV and syphilis
4. NAAT on first catch urine for C. trachomatis and N. gonorrhoeae

Answer 24

2. NAAT on first catch urine for C. trachomatis and N. gonorrhoeae, HIV serology, syphilis serology

Question 25

Newborn infant of mother with untreated gonorrhea. Next step in management? 1. CBC; cultures of conjunctiva, blood, CSF; IV ceftriaxone 2. CBC; cultures of conjunctiva, blood; IV ceftriaxone 3. Culture of conjunctiva; IM ceftriaxone 4. Culture of conjunctiva; treat according to results

Answer 25

3. Culture of conjunctiva; IM ceftriaxone

Question 26

Four week old baby with pneumonia on chest x-ray. Complete blood count shows eosinophilia. Management? 1. Ceftriaxone 2. Ampicillin 3. Erythromycin 4. No treatment

Answer 26

3. Erythromycin

Question 27

4 yo old develops two episodes of bloody diarrhea and mild abdominal pain after starting Clavulin. Afebrile and otherwise well. Stool tests positive for C. difficile. What would you do in addition to stopping antibiotics? 1. Metronidazole PO for 10 days 2. Clarithromycin PO for 10 days 3. Vancomycin PO for 10 days 4. Close follow-up with no antibiotics

Answer 27

4. Close follow-up with no antibiotics

Question 28

A 4 month old boy was exposed to his grandfather who was diagnosed with cavitary pulmonary TB. He is clinically well. Management? 1. Treat with rifampin 2. Give BCG 3. Treat with isoniazid 4. Do chest x-ray 5. If asymptomatic, no need for any interventions

Answer 28

4. Do chest x-ray

Question 29

Three year old boy exposed to a suspected case of pulmonary TB in the home. Clinically well, TST negative, CXR normal. Which is most appropriate? 1. No treatment is needed 2. No treatment at present; 9 months of isoniazid if repeat TST positive in 3 months 3. Start isoniazid now; discontinue in 3 months if still clinically well and repeat TST negative 4. Start 9 month course isoniazid now

Answer 29

3. Start isoniazid now; discontinue in 3 months if still clinically well and repeat TST negative

Question 30

A 7 year old boy stepped on a discarded needed while walking barefoot on the beach. He was bleeding. He was previously vaccinated against hepatitis B. Initial management? 1. Given hepatitis B vaccine and immune globulin 2. Give hepatitis B immune globulin 3. Send testing for anti-hepatitis B surface antigen 4. Reassure as previously vaccinated

Answer 30

3. Send testing for anti-hepatitis B surface antigen

Question 31

Six month old infant of mother with hepatitis C (antibody positive, RNA positive). Baby is well with normal liver enzymes and negative serology. What do you do? 1. Reassure, no further testing needed 2. Repeat HCV serology in 6 months 3. Liver biopsy 4. Measure HCV RNA in blood

Answer 31

1. Reassure, no further testing needed

Question 32

A child with ALL finished chemotherapy 1 month ago and was exposed to varicella zoster virus (VZV) 8 days ago. How do you treat? 1. VZV vaccine 2. VZIG 3. VZV vaccine and admit for IV acyclovir 4. Admit for IV acyclovir

Answer 32

2. VZIG

Question 33

A young child is bitten by a cat. Started on amoxicillin-clavulanate, but returns to ER with increasing redness and swelling. What should you do? 1. IV vancomycin and ceftriaxone 2. IV piperacillin-tazobactam 3. IV cloxacillin (or cefazolin) 4. Refer for surgical debridement

Answer 33

4. Refer for surgical debridement

Question 34

Two year old whose 5 year old sibling has meningococcal meningitis. What to do? 1. Ciprofloxacin only 2. Rifampin only 3. Vaccine + rifampin 4. Vaccine only

Answer 34

3. Vaccine + rifampin

Question 35

Three-year-old child, day 3 of chickenpox. Now afebrile and generally quite well. Few lesions, but not all crusted over. 1. Can return to daycare 2. Cannot return to daycare until all lesions crusted 3. Cannot return to daycare until 5 days after onset of rash regardless of lesion status 4. Cannot return to daycare until 5 days after onset of rash and all lesions crusted

Answer 35

1. Can return to daycare

Question 36

All of the following should be excluded from daycare except 1. Three year old with suspected scabies 2. Pertussis, 3 days after initiating erythromycin 3. E. coli 0157:H7, after resolution of diarrhea 4. Campylobacter, day 4 of illness 5. Hepatitis A, 10 days after onset of jaundice

Answer 36

5. Hepatitis A, 10 days after onset of jaundice

Question 37

Two-year old child admitted with fever, cough, rinorrhea and conjunctivitis. What infection control precautions do you recommend? 1. Gown, gloves and regular mask 2. Gown, gloves and N95 mask 3. Regular mask and alcohol rub when leave room 4. N95 mask and alcohol rub when leave room

Answer 37

1. Gown, gloves and regular mask