HIV Flashcards
What type of virus is HIV?
lentivirus (characterized by a long latent period)
Type ___ is predominant in Africa and Type ___ is dominant in America. Type ____ is slightly more virulent
II, I, I
What are the modes of transmission for HIV?
Primary: sex, drug use, vertical transmission from mother to child or breast feeding
Other: needle stick in health care setting, rare – artificial insemination and organ transplantation
What fluids can transmit HIV?
Blood, semen, vaginal fluids, breast milk, fluids contaminated with blood
Exposure to HIV is followed by ______, where symptoms may be non-specific. This usually happens 2-6 weeks after exposure
acute infection
On average, there is a “window” of ___ days before antibody tests come back positive for HIV, but it can take as long as ____ months
25, 3
Symptoms of acute infection include:
Flu-like symptoms: fever (present in 80-90%), Rash, fatigue, pharyngitis, generalized lymphadenopathy, myalgia/arthralgia, mucocutaneous ulceration, headache
During acute infection there is a dramatic drop in _____, meaning the viral load is very high
CD4 T cells
After acute infection has subsided, CD4 counts (increase/decrease)
increase slightly, body enters a long latent period
During the latent period, what happens to CD4 count?
It declines gradually
A diagnosis of AIDS can be confirmed when CD4 count drops below ______
200 cells/μL,
How long is the latent period for HIV?
May be as brief as a few months to median of 11 years before development of AIDS
What type of specimen is used to test for the presence of HIV?
Blood, buccal, or urine
What is the downside of antibody screening tests for HIV?
may have false negatives if test performed during window before antibodies develop
What is the downside to ELISA testing for HIV? What is used to alleviate this concern?
ELISA may have false positives with infection (TB, rheumatoid arthritis, autoimmune), recent vaccination, pregnancy, liver disease
Western Blot confirmatory test
ELISA tests are highly _____ and Western Blot tests are highly _____
sensitive(99.6%), specific (99%)
What are the pros and cons of P24 antigen testing?
Can detect antigen (p24 protein) in as little as 2 weeks (sometimes used in conjunction with antibody test in early testing situations, such as occupational exposure and sexual assault cases)
Lacks both sensitivity/specificity, so limited use
What is PCR NAAT (RNA or Nucleic Acid Amplification Test) generally used for? Does it detect infection early?
Testing in newborns and high risk individuals
Also used to monitor response to treatment
Yes, it can detect infection in as little as 11 days, but isn’t widely used or available in the community
Who should get tested for HIV?
CDC recommends HIV screening for patients aged 13–64 years in all health-care settings
Anyone who is high risk
HIV testing is now considered much more “routine”
For a patient who is positive for HIV, what should your initial HISTORY include?
Detailed medical history, including sexual and substance abuse history; vaccination history; previous STDs; travel history; and assessment for specific HIV-related symptoms or diagnoses
What kind of testing should you initially perform on someone who has been diagnosed with HIV?
testing for gonorrhea and chlamydia
complete blood and platelet counts, blood chemistry profile, and lipid profile;
toxoplasma antibody test
testing for antibodies to hepatitis C virus
history of Hep A or Hep B, vaccination if applicable
syphilis serology
CD4 T-lymphocyte analysis and determination of HIV plasma viral load
HIV genotypic resistance testing
tuberculin skin test
urinalysis
chest radiograph
In addition to initial testing and establishment of routine medical care, what are some important things to consider for a new HIV patient?
Counseling, social services, partner notification (voluntary or confidentially through health department), prophylaxis for certain opportunistic infections, immediate administration of antiviral therapy
What are some considerations you should take for a patient who is pregnant?
Screening for HIV, and if positive, antiviral therapy as soon as known to be infected to decrease risk of perinatal transmission
counseling re: avoidance of breast feeding
Definitive testing in infants under 18 months is usually done by nucleic acid testing (as mother’s antibodies will be transferred)
Should also consider testing other children if their status is not known
Is antiviral therapy effective in reducing transmission from mother to baby?
Yes, very effective. Chance of transmission drops for 15-25% to <2% if initiated early
What are people with HIV/AIDS most at risk for?
opportunistic infections
What are the pros and cons of Orasure HIV 1 and Oraquick Advance HIV 1/2 rapid testing
They can be administered by a non-clinician in a community setting
They are not the most accurate type of testing and always require confirmation testing
What is important to remember about virtually all types of HIV testing?
They require a confirmatory test, typically a Western Blot to rule out false positives
What are the stages of HIV?
Exposure, acute infection, latent period (asymptomatic infection), symptomatic infection, AIDS
Why is early detection important?
Because patients who start HAART (Highly active antiretroviral therapy ) as soon as HIV is detected are more likely to experience slowed progression of disease
Is HIV a reportable disease?
Yes
What combination of (two) tests represents the most realistic means of improving screening in the general community? (Hint: developed by Lab Corps)
The antibody/antigen combination test
Detects antibody to HIV-1 and/or HIV-2 and antigen (specifically p24 antigen) to increase the likelihood of detecting infection
Less likely to miss infection in window period although still has a 1 week window between exposure and development of P24 antigen
What is Truvada?
Post-exposure prophylaxis for sex or injection drug partners who may have been exposed to HIV + person’s blood or genital secretions in past 72 hours
Also used as a pre-exposure prophylaxis to prevent transmission to people who’s partners are HIV positive
