unit 9 part 2

Question 1

vaccines and their effects on the incidence of measles and mumps

Answer 1

MMR or MMRV (measles, mumps, rubella, varicella-zoster virus)
–> after 2 doses it is 97% effective in preventing
lead to 99% decrease in cases

Question 2

clinical manifestations of the mumps virus

Answer 2

prodromal period of nonspecific symptoms then parotitis (swollen parotid glands)

Question 3

pathogenesis of the parainfluenza viruses

Answer 3

causes infection in the upper respiratory tract that can descend to the lower respiratory tract

Question 4

most common cause of the croup

Answer 4

PIV-1

Question 5

age group in which respiratory syncytial virus causes a life threatening pneumonia

Answer 5

most common in infants under the age of 1

Question 6

pathogenesis of RSV

Answer 6

upper respiratory tract infection that commonly descends to lower respiratory tract due to syncytia (fusion of cells in 1 big one)

Question 7

months of the year when RSV is most often isolated

Answer 7

precedes the influenza season and occurs early fall into early winter

Question 8

RSV vs human metapneumovirus

Answer 8

RSV has a higher risk and infection rate in younger children than hmpv

Question 9

most common cause of lower respiratory tract infections in young children

Answer 9

RSV

Question 10

unique features of retrovirus replication

Answer 10

reverse transcribe RNA into DNA of host cell to infect it

Question 11

taxonomy of HIV

Answer 11

disease descended from apes

two types of HIV (HIV-1 and HIV-2)

–> HIV-1 has groups M,N,O,P (m is most common)
–> HIV-2 has groups A-I

Question 12

tropism of HIV

Answer 12

CD4+ cells as well as monocytes, macrophages, microglia, and dendritic cells

Question 13

how are CD4+ cells attacked by HIV

Answer 13

gp120 on envelope binds to it and gp41 fuses membrane

Question 14

secondary receptors of HIV

Answer 14

CCR5 (t cells) CXCR4 (t helper cells)

Question 15

pathology of HIV (modes of transmission and receptor sites)

Question 16

how does HIV affect the immune system

Answer 16

cell-free spread in which there is rapid viral replication
-> decrease in T helper cell because they are attacked by CD8 cells
–> leads to AIDS
–> neurologic diseases

Question 17

CD4 count in AIDS

Answer 17

less than 200

Question 18

clinical stages of HIV

Answer 18

acute phase: asymptomatic or flu/mono like symptoms (associated with high viral load)

chronic infection: latency

Question 19

clinical latency of HIV

Answer 19

no symptoms or manifestations but HIV can still be transmitted

Question 20

HIV vs AIDs

Answer 20

progression to aids takes 10 years
–> causes recurrent/prolonged respiratory infections

Question 21

oppurtunistic infections and carcinomas associated with AIDS

Answer 21

candidiasis, fungal infections, pneumonia, toxoplasmosis

kaposi’s sarcoma, cervical cancer

Question 22

epidemiology of AIDS and the region with the greatest incidence

Answer 22

african region remains most severly affected by AIDS (gay/bisexual men)

Question 23

principles of the serologic tests used to screen for HIV antigens

Answer 23

seroconversion used to detect antibodies
–> rapid Ab test as preliminary and 4th generation AB test detects p24 antigen
then sent for confirmatory testing

Question 24

ratio of CD4 counts in HIV infections

Answer 24

decrease in CD4+ is directly associated with increase in HIV RNA or viral load (and presence of symptoms)

Question 25

timeline when HIV serologic markers are detectable

Question 26

algorithm for HIV testing

Answer 26

HIV1-2 Ag/Ab immunoassay, if positive then HIV 1-2 Ag/Ab differentiation immunoassay, if undetectable then HIV- NAt

Question 27

treatment of HIV

Answer 27

highly active antiretroviral therapy (HAART) which is a 3-4 drug regimen to maximize effectiveness of reducing HIV

Question 28

classes of anti HIV drigs

Answer 28

1. fusion inhibitors (prevents binding)
2. nucleoside reverse transcriptase inhibitor (prevents binding)
3. protease inhibitor (prevents cleaving)
4. integrase inhibitors (prevents integration of viral genome)

Question 29

evaluate methods of determining HIV drug resistance

Answer 29

genotyping by performing RT-PCr and DNA sequencing to determine which drugs the virus is sensitive to
–> prevents resistance to drugs before initiation of therapy

Question 30

potential reasons for treatment failures in HIV patients

Answer 30

drug resistance