8: Viruses

Question 1

Are viruses extracellular or intracellular?

Answer 1

Obligate intracellular

Question 2

Acronym for DNA viruses

Answer 2

HHAPPP(Y): herpesvirus, hepadnavirus, adenovirus, parvovirus, poxvirus, papovavirus

Question 3

WBCs in bacterial vs viral infection

Answer 3

Bacteria: higher counts, >15,000, neutrophil left shift
Viral: +/- elevated WBCs, lymphocytosis

Question 4

Fever in bacterial vs viral infection

Answer 4

Bacterial: higher
Viral: lower, but can be high in kids

Question 5

Stages of rash in chicken pox

Answer 5

Papule s -> itchy vesicles -> crusty scabs (all exist at the same time(

Question 6

Two ways to Dx EBV

Answer 6

1. Monospot: heterophile Ab test

2. If monospot is negative -> EBV Ab test

Question 7

Saying for HHV-6

Answer 7

When the fever goes away, the rose blooms

Question 8

Six types of Ags/Abs tested for in hepatitis B serology and what they indiciate***

Answer 8

1. HBsAg: infection present
2. HBsAb: infection resolved/immune
3. HBeAg: high infectivity
4. Anti-HBeAg: low infectivity
5. Anti-HBcAg IgM: new infection
6. Anti-HBcAg IgG: older or previous infection

Question 9

Common cold causes

Answer 9

Rhinovirus (#1), coronavirus (#2), adenovirus, RSV, parainfluenza

Question 10

RSV

Answer 10

1 cause of PNA in young children

Question 11

Histo of RSV

Answer 11

Giant cell formation

Question 12

What condition does parainfluenza cause?

Answer 12

Croup

Question 13

Population most susceptible to polyomaviruses

Answer 13

Immunocompromised

Question 14

Antigenic drift vs antigenic shift

Answer 14

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

Question 15

What two factors are changed in antigenic shift and drift?

Answer 15

Hemagglutinin, neuraminidase

Question 16

Three types of paramyxoviridae (besides measles and mumps)

Answer 16

Parainfluenza, RSV, metapneumovirus

Question 17

Most prevalent cause of HIV in the world vs in US

Answer 17

World: heterosexual contact
US: homosexual and bisexual community, esp. MSM

Question 18

What type of virus is HIV and how does that work?

Answer 18

RNA retrovirus with a reverse transcriptase: RNA -> DNA -> integrates into T cell DNA -> proteins

Question 19

What cells does HIV affect most?

Answer 19

CD4 T cells

Question 20

What is used to screen and diagnose HIV?**

Answer 20

Ab test for P24 capsid

Question 21

What virus should be considered in an adult with mono-like sx but a negative Monospot test

Answer 21

HIV (acute phase)