Virology Flashcards
What are the 6 DNA virus families?
Adenovirus Hepadnavirus Herpesvirus Papovavirus Parvovirus Poxvirus
What are the 3 arbovirus families?
Togavirus (Chikungunya)
Bunyavirus (Hanya)
Flavivirus (WNV, Zika, also HCV)
Shell vial assay
Rapid (overnight) tissue culture assay
Use fluorescent antibody to identify viral cytopathic effect
Direct fluorescence assay
Use fluorescent antibodies for viral antigens to directly observe viral effect.
Most appropriate for herpesviridae
Adenovirus
Icosahedral, non-enveloped DNA virus.
40+ serovars, causes many infections including keratoconjunctivitis, gastroenteritis, pneumonia, hemorrhagic cystitis
Homogeneous smudgy intranuclear inclusions without halos
Paramyxoviridae
Causes syncytia in infected tissue (usually pulmonary)
Measles: Pink intranuclear and intracytoplasmic inclusions
RSV: Pink intraCYTOplasmic inclusions only
Parainfluenza: No inclusions
Hantavirus
Bunyavirus, contracted by inhalation of rodent feces (SW US)
Causes severe pulmonary edema, shock, coagulopathy, arrhythmia
Hematologic PENTAD: Hemoconcentration, neutrophilia, no toxic granulation, >10% immunoblasts, thrombocytopenia
Hepatitis B serology (elements, order)
HBV DNA - Active viremia HBcAg - Active viremia HBcAb - Can be total or IgM (acute infection) HBsAg - Active viremia HBsAb - Immunity HBeAg - Infectivity HBeAb -
HBsAg»_space; HbeAg»_space; HBcAb»_space; HBeAb»_space; HBsAb
Hepatitis B serology patterns
Naive: None
Acute infection: HBcAb IgM
Resolved infection: HBsAb, HBcAb IgG
Chronic active carrier: HBsAg, HBcAg, HBeAb NEGATIVE
Chronic inactive carrier: HBsAg, HBcAg, HBeAb POSITIVE
COVID-19
Enveloped ssRNA virus
Causes lymphopenia (among other stuff…)
HIV testing
Screen with PCR or EIA (include p24 to shorten window)
Confirm with western-blot (high specificity): Need p160/120 or p41+p24 bands.
Needlestick transmission
HBV most transmissible
HCV most common in healthcare settings
CMV
75% of general population seropositive
RSV
Causes bronchiolitis in fall/winter months.
Diagnose with NAT or EIA.
No vaccine. Monoclonal antibody (palivizumab)
Influenza
A (infects animals and humans), B (humans only)
Neuraminidase and hemagglutinin.
Genetic drift & shift.
Secondary bacterial pneumonias
BK virus
Polyoma (papova) virus
Ubiquitous (90% seropositive by 10yo). Affects 5% of transplant kidneys.
Diagnose by urine PCR or cytology.
HAART
Start if >100k/mL loads. Get genotyping to guide therapy.
Test again in 2-8 weeks, then 3-4 months.
HCV
Flavivirus (RNA)
Genotype 1 (most common, longest treatment) 2, 3 also seen in US. Genotypes 4-6 rare.
WNV
Arboviral meningoencephalitis of summer/fall.
Transmitted by mosquitoes, but also transfusion/transplant and vertical.
Diagnose with serology or PCR>
Flu treatments
Neuraminidase inhibitors (Oseltamivir, Zanamivir): For influenza A+B
Adamantine drugs: Influenza A only
**Start within 48hrs of symptom onset
Blood screening for HBV
EIA for HBcAb (IgM or total)
EIA for HBsAg
May also include NAT for HBV DNA
Rabies
Rhabdovirus. Spread by rodent bite. Tropism for neurons.
Diagnose by PCR, serology, postmortem histology.
Treatment: Rabies vaccine and rabies immune globulin