8: Viruses Flashcards
Are viruses extracellular or intracellular?
Obligate intracellular
Acronym for DNA viruses
HHAPPP(Y): herpesvirus, hepadnavirus, adenovirus, parvovirus, poxvirus, papovavirus
WBCs in bacterial vs viral infection
Bacteria: higher counts, >15,000, neutrophil left shift
Viral: +/- elevated WBCs, lymphocytosis
Fever in bacterial vs viral infection
Bacterial: higher
Viral: lower, but can be high in kids
Stages of rash in chicken pox
Papule s -> itchy vesicles -> crusty scabs (all exist at the same time(
Two ways to Dx EBV
- Monospot: heterophile Ab test
2. If monospot is negative -> EBV Ab test
Saying for HHV-6
When the fever goes away, the rose blooms
Six types of Ags/Abs tested for in hepatitis B serology and what they indiciate***
- HBsAg: infection present
- HBsAb: infection resolved/immune
- HBeAg: high infectivity
- Anti-HBeAg: low infectivity
- Anti-HBcAg IgM: new infection
- Anti-HBcAg IgG: older or previous infection
Common cold causes
Rhinovirus (#1), coronavirus (#2), adenovirus, RSV, parainfluenza
RSV
1 cause of PNA in young children
Histo of RSV
Giant cell formation
What condition does parainfluenza cause?
Croup
Population most susceptible to polyomaviruses
Immunocompromised
Antigenic drift vs antigenic shift
Drift: mutation results in small changes - previous Abs partially recognize but can still cause mild infection
Shift: trading of RNA between viruses -> completely new virus, everyone is susceptible -> pandemic can occur
What two factors are changed in antigenic shift and drift?
Hemagglutinin, neuraminidase
Three types of paramyxoviridae (besides measles and mumps)
Parainfluenza, RSV, metapneumovirus
Most prevalent cause of HIV in the world vs in US
World: heterosexual contact
US: homosexual and bisexual community, esp. MSM
What type of virus is HIV and how does that work?
RNA retrovirus with a reverse transcriptase: RNA -> DNA -> integrates into T cell DNA -> proteins
What cells does HIV affect most?
CD4 T cells
What is used to screen and diagnose HIV?**
Ab test for P24 capsid
What virus should be considered in an adult with mono-like sx but a negative Monospot test
HIV (acute phase)
