HIV Flashcards
(133 cards)
what is the pathogenesis of contracting HIV
HIV is a RNA retrovirus that binds to receptor sites on CD4 (helper T or lymphocytes) cell surface, fuses and enters cell
HIV releases reverse transcriptase and instructs host DNA to copy and mass produce the virus –> lymph nodes (which have lots of CD4 receptors) quickly become site of massive viral replication
how is HIV most often spread today
through sharing contaminated needles in IV drug use
what are modes of transmission for HIV
sexual contact
blood or blood products
perinatal-mother to fetus
can a mother w HIV have a baby without passing it on? how?
yes
take antiretroviral meds (HAART drugs) during pregnancy
avoid breastfeeding
what are HIV prevention strategies
safe sex
screen blood
regular testing for high risk
avoid IV drug use
HAART drugs for pregnancy
what is needed to determine someone to be HIV (+)
(+) viral load test or (+) HIV antibody testing
what is viral load testing
tests for the presence of HIV RNA in blood plasma
what is HIV antibody testing
tests for HIV antibodies present in bloodstream after seroconversion
what is seroconversion
time it takes for our body to develop immune cells to fight infection
viral load testing vs HIV antibody testing: detection time
viral load = quick
- 2-12wks after infection
HIV antibody
- 3-12mo after infection
what are the 4 clinical stages of HIV
- acute infection
- asymptomatic HIV dz
- symptomatic HIV dz
- advanced HIV dz/ AIDS
what is the acute infection clinical stage defined by
initial infection until seroconversion
- usually w/i 12wks
what clinical manifestations are present at the acute infection clinical stage
often asymptomatic or flu-like sx (diarrhea, fever, swollen lymph nodes, fatigue, myalgias, sore throat)
less often: meningitis, encephalitis, sz, psychosis, cranial neuropathy
in developed countries, what is the most common clinical stage to encounter someone w HIV in
asymptomatic HIV
drugs are available to keep people asymptomatic and in this stage as long as possible
dx criteria for asymptomatic HIV dz
CD4 count >500ul
clinical manifestations for asymptomatic HIV dz clinical stage
periods of general lymphadenopathy but otherwise sx free
duration of asymptomatic HIV dz clinical stage
1-20yrs
- depends on medical management
- depends on virus subtype
what are the lab values for asymptomatic HIV dz clinical stage
(+) antibody test
slow decline in CD4 count
slow inc in viral load
dx criteria for symptomatic HIV dz
CD4 count: 201-499ul
dx criteria for advanced HIV dz /AIDS
CD4 count <200ul
clinical manifestations of symptomatic HIV dz
wt loss
fatigue
fever
night sweats
emergence of neuro sx
clinical manifestations of advanced HIV dz/AIDS
wasting syndrome
opportunistic infections
AIDS related dementia
AIDS defining illnesses
what are the 3 main categories of AIDS defining illnesses
lot are neurologic
cancers
pulmonary
CD4 count throughout the clinical stages
asymptomatic >500
symptomatic 201-499
AIDS <200