HIV Flashcards
What is HIV?
It is an RNA single stranded virus that uses human hosts to replicate. It is a retrovirus.
What is a retrovirus?
It is a virus that contains reverse transcriptase. It converts
How many types of HIV viruses are there?
hiv 2 and hiv 2. hiv 2 is mainly in south african, and parts of india. they are the same symptomatically, but 2 has a slower rate of progression.
What are the primary targets of HIV cells?
CD4 cells.
How does HIV get into cells?
viral enveloped protein (gp120) binds to cells with cd4 receptor
What are ways that HIV can be transmitted?
through sexual contact, mother to child, body fluids, tissue transplantation.
How is HIV NOT transmitted?
saliva, respiratory droplets, insects, or close personal contact.
Describe the early disease progression for HIV
lasts about 2-4 weeks. HIV localizes to lymphoid tissues. Virus rapidly spreads at first. You see acute retroviral syndrome.
What is acute retroviral syndrome:
fever, fatigue, rash, headache, lymphadnoapathy, sore throat, myalgia, nausea, vomit, diarrhea, night sweats.
When can you detect the HIV antibody?
usually at 3-8 weeks after infection. Time between infection and detectable levels is called the window period. Patient is usually asymptomatic during this period. HIV IS STILL REPLICATING.
What is the severity of the illness determined by?
Amount of virus in the body, degree of immune suppression: CD4 lymphocyte counts decrease. When CD4 lymphocytes decreased to less than 500, you typically start to develop opportunistic infections.
What additional lab tests might give you clues that an HIV infection is present?
anemia, lymphopenia, throboyctopenia.
What are some common HIV associated complications:
wasting, pneumocytits jiroveci, kaposi’s sarcoma, thrush. PE may show adenopathy. Risks include: IDU, MSM, HIV infected partner.
What is the final stage associated with HIV infection?
AIDS (acquired immunodeficiency syndrome). CD4 count <200 or AIDS defining condition (opportunistic infection or cancer).
Describe the typical course of an HIV infected individual:
- primary infection
- Acute HIV syndrome
- clinical latency
- Constitutional symptoms
- Opportunistic disease
- death
What are the reasons for testing of HIV?
ID those with infection so antiviral therapy can be initiated. ID carrier who may transmit infection to other. Monitor disease progression. Eval treatment efficacy.
What is the most common type of HIV testing?
Serology for antibody, Detect HIV Antibody, or Nucleic Acid testing. It is less common to due a culture because it is so dangerous.
What is Opt-Out testing?
Testing will be performed unless patient says otherwise. Research indicates more patients will consent to testing if they perceive it as part of routine.
What is the testing algorithm?
- perform screening test: EIA (if 2/3 positive…then..)
- confirmatory test – Western Blot
3.
What is the screening test for HIV?
Enzyme immunoassay that will detect HIV antibodies in the serum. sensitivity and specificity is 99%. If positive, then EIA is REPEATED. 2/3 tests are positive then confirmatory testing is automatically performed.
What is the western blot test?
It is the confirmatory test. Viral components are separated via electrophoresis. sensitivity and specificity is >99%
How would you know if a patient is positive with the WB test?
p24 and p120/160 bands are present. It is positive if 2/3 antigen-antibodies are present.
How is a patient confirmed HIV positive?
if they have 2/3 screening tests are positive and confirmatory western blot is also positive.
What is the screens are positive but confirmatory is negative
then patient is considered negative. follow up in 4 weeks.
