Infectious 2

Question 0

Linked to gastroenteritis in enclosed populations (daycare, schools, cruises) – clinical features? Duration? Diagnosis? Management?

Answer 0

Norwalk virus

1. Vomiting most prominent
2. 2-3 day duration (shorter than other viral causes)

Diagnosis based clinical features

Supportive

Question 1

Most common infectious agent causing gastroenteritis? Peak incidents? Incubation? Clinical Features? Diagnosis? Management? Complication?

Answer 1

Rotavirus; winter; Picogordo

1. 1-3 Day incubation
2. Vomiting, diarrhea, dehydration for 4-7 days
3. Sometimes URI symptoms

ELISA test

1. Supportive therapy and early feedings to prevent gut atrophy
2. Transient lactose intolerance

Question 2

Bacterial diarrhea with absent stool WBCs? Present stool WBCs? Either present or absent stool WBCs?

Answer 2

Toxigenic E. coli, pathogenic E. coli, campylobacter, Yersinia

Hemorrhagic E. coli, Shigella

Salmonella

Question 3

Bacterial diarrhea

1. Major cause of travelers diarrhea? Tx?
2. Commonly Causes hemolytic uremic syndrome? Tx?
3. Bloody diarrhea and seizures? Tx?
4. Most common cause of bloody diarrhea in US? Tx?
5. Can cause mesenteric adenitis? Tx?
6. With water loss? Tx?

Answer 3

1. toxigenic E. coli – quinolones, sulfonamides
2. Enterohemorrhagic E. coli
3. Shigella – ceftriaxone, fluoroquinolone
4. Campylobacter – Erythromycin
5. Yersinia – ceftriaxone
6. Cholera – just fluid replacement

Question 4

Classic electrolyte finding in diarrhea (chlorine)?

Answer 4

Non-anion gap hyperchloremic metabolic acidosis

Question 5

HIV transmission in children? Factors that increase transmission? Factors that decrease transmission?

Answer 5

1. Perinatal transmission (95%)
2. Breast-feeding
3. High maternal viral load
4. Advanced maternal disease
5. maternal genital infections (Chorioamnionitis)
6. Premature birth
7. Prolonged rupture of membranes
8. Undetectable viral load
9. C-section
10. Compliance with therapy
11. Infant postexposure prophylaxis

Question 6

Clinical features of neonatal HIV infection? Diagnose by? Test that should be avoided?

Answer 6

Most infants are asymptomatic first year of life

1. Failure to thrive
2. Recurrent infections, thrush
3. Lymphadenopathy, parotitis
4. Loss of developmental milestones
5. Thrombocytopenia
6. Severe varicella infection

HIV DNA PCR monthly until four months page

ELISA - Maternal antibody present in children until two years of age

Question 7

Management of infant born to mother with HIV?

Answer 7

1. Zidovudine for six weeks – postexposure prophylaxis
2. Bactrim for PCP until four months of negative HIV PCR
3. No breast-feeding
4. Urine CMV culture

Question 8

Management for children positive for HIV?

Answer 8

1. HAART therapy
2. Prophylaxis based on CD4 count and age
3. Immunizations (except varicella)
4. Annual eye exams for CMV retinitis in children who are CMV antibody positive

Question 9

Infectious mononucleosis – causes? Clinical features? Lab findings? Diagnosis based on age? Management?

Answer 9

EBV, CMV, HIV, toxoplasmosis

1. Fever, malaise, fatigue
2. Pharyngitis – exudative
3. Posterior cervical adenopathy
4. Hepatosplenomegaly
5. Macular rash

Labs shows atypical lymphocytes, neutropenia, thrombocytopenia, elevated transaminases

1. Monospot to test for heterophile antibody (only in children over four)
2. EBV antibody titers in children under four
3. PCR

Supportive. Corticosteroids sometimes for severe pharyngitis

Question 10

Complications of infectious mononucleosis in short term? During tx? Long term?

Answer 10

1. Splenic rupture
2. Neurologic – cranial nerve palsies, encephalitis
3. Severe pharyngitis – upper airway obstruction

Amoxicillin-associated rash – diffuse juridic maculopapular rash one week after starting abx

Malignancy – nasopharyngeal carcinoma, Burkitt’s lymphoma

Question 11

Measles – cause? Clinical features? Diagnosis? Management?

Answer 11

Paramyxovirus rubeola

1. Three C’s (cough, conjunctivitis, Coroza)
2. Enanthem – Koplik spots on buccal mucosa
3. Exanthem – rash beginning in the head and spreading within 24 hours
4. Fever

Serologic testing

Vitamin A, supportive care

Question 12

Complications of measles?

Answer 12

1. Bacterial pneumonia – most common cause of mortality
2. Otitis media
3. Laryngotracheitis
4. Encephalomyelitis
5. Subacute sclerosing panencephalitis

Question 13

Rubella – virus family? Incubation? Clinical features? Diagnosis? Management? Complications?

Answer 13

Togavirus

Often asymptomatic with incubation period of 2 to 3 weeks

1. Prodrome of URI and fever
2. Painful suboccipital, posterior auricular lymphadenopathy
3. Exanthem beginning on face and spreading to trunk
4. Fever less than 38

Viral culture and serology

Supportive

1. Meningioencephalitis
2. Polyarteritis in females

Question 14

Congenital Rubella?

Answer 14

1. Blueberry muffin baby -Thrombocytopenia, jaundice
2. Hepatosplenomegaly
3. Congenital cataracts
4. Sensorineural hearing loss
5. Patent ductus arteriosus
6. Mental retardation, hypertension, DM

Question 15

Allergic bronchopulmonary aspergillosis – characterized by? Labs? Management?

Answer 15

1. Wheezing
2. Eosinophilia
3. Pulmonary infiltrates

Elevated Aspergillus specific immunoglobulin E

Corticosteroids and antifungal

Question 16

Patients with a high-risk of giardiasis?

Answer 16

1. Travelers to Russia
2. Drink contaminated Mountain water in western United States
3. Day care center outbreak

Question 17

Diagnosis malaria with?

Answer 17

Giemsa stain

Question 18

Most common cause of infectious chorioretinitis? Triad? Transmission?

Answer 18

Toxoplasmosis

Hydrocephalus, intracranial calcifications, chorioretinitis

Cat feces

Question 19

1. Most common Helminth infection in the US? Treatment?
2. Loffler syndrome? Treatment?
3. Helminth infection that causes tenesmus, bloody diarrhea, rectal prolapse? Treatment?
4. Helminth that can cause Fe deficiency anemia? Tx?
5. Migrating, pruritic, erythematous tracks on skin? Tx?
6. Ocular larva migrans? Tx?

Answer 19

1. Enterobius – albendazole
2. Ascaris lumbercoides - transient pneumonitis from migration through lungs causing fever, eosinophilia
3. Trichuris trichuria - Albendazole
4. Necantor americus and Ancylostoma duodenale - Albendazole
5. Cutaneous larva migrans – ivermectin
6. Toxocara canis – albendazole

Question 20

Cysticercosis - organism? Transmission? Clinical features? Diagnosis? Management?

Answer 20

Taenia solium. Fecal-oral.

1. No symptoms until tapeworm is in muscle, subcutaneous tissue, brain
2. Subcutaneous nodules – calcified on x-ray
3. Neurocysticercosis – 4th ventricle involvement causing Seizures, hydrocephalus, stroke
4. stool O&P
5. Serology
6. CT/MRI – solitary parenchymal cyst on multiple calcifications

Anti-parasitics or if only calcified lesions – anticonvulsants

Question 21

Rocky Mountain spotted fever – Gram stain shows? Clinical features? Laboratory findings? Diagnosis? Management?

Answer 21

Gram-negative intracellular coccobacillus

1. Hypotension
2. Petechial rash beginning on the wrist/ankles moving centrally
3. Hepatosplenomegaly
4. CNS – headache, seizures
5. Fever and myalgia

Thrombocytopenia, elevated transaminases, hyponatremia

Serologic testing

Doxycycline

Question 22

Ehrlichiosis – Clinical features? Laboratory findings? Diagnosis? Management?

Answer 22

Same symptoms as Rocky Mountain spotted fever WITHOUT rash (Fever, headache, myalgias, lymphadenopathy)

Thrombocytopenia, elevated transaminases, hyponatremia

Serology and PCR

Doxycycline

Question 23

Bartonella – clinical features? Diagnosis? Management?

Answer 23

1. Papule along the lines of scratch, followed by lymphadenopathy after two weeks
2. Fever
3. Parinaud oculoglandular syndrome (conjunctivitis and preauricular lymphadenitis)

Elevated serum IgM antibody to bartonella

Supportive care

Question 24

Tuberculosis disease (vs tuberculosis)? Transmission of TB in children under 12? Extrapulmonary TB?

Answer 24

Signs and symptoms of TB without positive findings chest radiograph Not contagious because cough is minimal and lesions are small 1. Scrofula (cervical lymphadenitis) 2. meningitis 3. ileitis 4. joint 5. Pott's disease 6. Miliary

Question 25

Radiographic features of TB?

Answer 25

1. Hilar/mediastinal lymphadenopathy 2. Ghon complex – parenchymal infiltrates with enlarged hilar lymph nodes 3. Lobar involvement, pleural effusion

Question 26

Positive tuberculin skin test in children if?

Answer 26

>5 mm in children with close contact with persons with TB, suggestive x-ray findings, immunocompromised >10 mm in children younger than four, chronic medical condition, area endemic for TB >15 mm in children older than four with no other risk factors

Question 27

Definite diagnosis of TB if?

Answer 27

1. Positive culture from gastric aspirates 2. Positive staining of fluid for acid-fast bacilli 3. Caseating granulomas on biopsy