Viruses

Question 1

Variola (smallpox): E,C, D, T, PPx, Control

Answer 1

E: only cases would be bioterrorism; transmission is by respiratory droplets
C: a week of prodrome and vesicular rash that starts on face/hands/feet and spreads centrally (contrast to Varicella which starts on trunk with minimal prodrome), can involve palms and soles (contrast Varicella and Monkeypox), lesions are synchronous (contrast Varicella and Monkeypox)
D: try to rule out other diseases, CDC has PCR that you can do on a lesion
T: supportive can and an experimental drug called tecovirmat (stockpiled by the government)
PPx: immediate vaccination (can be effective up to 7d) which has no contraindications when used as post-exposure prophylaxis
Control: infectious until all scabs separate and have come off; isolate exposures at home for 17d; not viable for long in the environment

Question 2

EBV clinical syndromes

Answer 2

• -Mononucleosis: fevers, tonsillitis, pharyngitis (often with exudate), LAD (cervical most common), fatigue, N/V, rash (90% get morbilliform rash after ampicillin which is not an allergy), splenomegaly (50%)
• -Mononucleosis in the elderly: often no pharyngitis, hepatitis more common (AST/ALT in hundreds, almost never in thousands); sometimes a cause of FUO with no real other sx (+/-LAD)
• -Mononucleosis complications: can get leukocytosis as high as 50,000; aplastic anemia, thrombocytopenia, Guillain-Barré, viral meningitis, transverse myelitis, optic neuritis, spleen rupture, airway obstruction, rarely myocarditis or pancreatitis
• -Other associated conditions: oral hairy leukoplakia, nasopharyngeal carcinoma, Burkitt’s lymphoma, hemophagocytic lymphohistiocytosis (HLH), PTLD
• -HLH: T cell lymphoproliferative disorder; fever, pancytopenia, high ferritin, HSM, encephalitis, rash, coagulopathy, adenopathy, hepatitis; confirm with bone marrow bx; etoposide and corticosteroids are mainstays of therapy

Question 3

EBV diagnostics

Answer 3

• -Primary infection: VCA IgM, +/- VCA IgG, +/- EA IgG
• -Acute infection: +/- VCA IgM, VCA IgG, EA IgG, +/- EBNA IgG
• -Past infection: VCA IgG, EBNA IgG
• -Reactivation: +/- VCA IgM, VCA IgG, +/- EA IgG, EBNA IgG

Key point: EA IgG and VCA IgM suggest acute or recent infection

Question 4

Hantavirus: C

Answer 4

• -incubation of 4-30d
• -first febrile with myalgias, malaise, sometimes GI sx then severe cardiopulmonary phase (dry cough → pulmonary edema → shock with capillary leakage); look for following lab abnormalities
• -thrombocytopenia (98%)
• -hemoconcentraion
• -left shift with atypical lymphs
• -PT elevated
• -LFTs abnormal

Question 5

Treatments for respiratory viruses (6)

Answer 5

• -influenza: oseltamivir or IV zanamivir (treat all hospitalized patients and any outpatient with comorbidities)
• -RSV: ribavirin, IVIG
• -parainfluenza: maybe IVIG
• -adenovirus: cidofovir if immunocompromised
• -human metapneumovirus: maybe IVIG
• -coronavirus: supportive

Question 6

Varicella: T, PPx

Answer 6

T primary: acyclovir or valacyclovir for 5d if within 24hrs of rash or after 24hrs if comorbidities or complications
T reactivation: valacyclovir in 72hrs but could get benefit beyond that
PPx (if no immunity): if healthy give vaccine; if HIV and CD4 >200 give vaccine; if HIV and CD4 <200 give acyclovir); if pregnant or other immunosuppressed give VariZIG

Question 7

HHV clinical syndrome

Answer 7

HHV-6: roseola; major cause of fever and febrile seizure in children under 1yo, 25% w/ rash; if immunocompromised can get myelosuppression, penumonitis, meningitis, rash
HHV-7: usually just in kids; fever, rash, LAD
HHV-8: KS, B cell lymphoma, Castleman’s

Question 8

Dengue: C, D

Answer 8

C: leukopenia, thrombocytopenia, fever, retro-orbital pain, mucosal bleeding, severe dengue with hemoconcentration, effusions, hemorrhage
D: IgM, PCR

Question 9

Yellow fever: E, C, DDx

Answer 9

E: sub-Saharan Africa and the Amazon
C: fever, n/v, jaundice, oral bleeding, thrombocytopenia, neutropenia, elevated PT/PTT, proteinuria (early diagnostic clue), ARF, transaminitis
DDx: dengue (only has mild hepatitis and no renal issues), lepto (only has mild transaminitis), hepB (only rarely renal disease

Question 10

Chikungunya: E, C

Answer 10

E: mosquitoes, around the Indian Ocean, urban
C: conjunctivitis, fevers, leukopenia, elevated AST/ALT, rash, distal polyarthritis, edema, then tenosynovitis, can persist

Question 11

CMV Tx

Answer 11

• -Ganciclovir (5mg/kg) IV q12 or (if mild disease) valganciclovir
• -Tx at least 2wks but until VL undetectable (then check weekly for 2wks)
• -If severe disease consider IVIG or CMVIG
• -First mutation is UL97 and is more mild then UL54; foscarnet is next line

Question 12

BK Virus in transplant: C, D, T

Answer 12

C: nephropathy in 15% of renal transplant patients (usually within 1yr), before rise in Cr you will see it in blood and urine on PCR
D: biopsy must be done to exclude rejection
T: reduce immunosuppression, maybe cidofovir

Question 13

HTLV-1: E, C, D

Answer 13

E: most in tropics, transmitted by sex, blood, breast milk (HTLV-II likely doesn’t cause disease but can react with HTLV diagnostic tests)
C: 95% asymptomatic, associated with T cell leukemia in 1% after long latency period, myelopathy (tropical spastic paraparesis in <1%)
D: ELISA + Western blot