HIV Flashcards
EOR exam 5 (174 cards)
what type of virus is HIV?
- HIV is a single stranded RNA retrovirus
what cells does HIV target and destroy?
- HIV targets and destroys CD4 T-helper cells
How does HIV replicate in the body?
1.HIV uses the host’s CD4 T cells to replicate; once replicated, the virus bursts through the CD4 cell membrane, destroying the cell.
What is the consequence of increased viral load?
- As HIV replicates and the viral load increases, the CD4 count decreases.
What happens when the CD4 count falls below 200 cells/mm³?
- The immune system can no longer ward off opportunistic infections (OIs) and AIDS-related malignancies (e.g., Kaposi’s sarcoma).
How is HIV transmitted?
- HIV is transmitted by direct contact with infected body fluids, including blood, semen, vaginal or rectal secretions, or breast milk.
What parts of the body allow HIV entry?
- Through mucus membranes or open wounds
What are common routes of HIV infection?
- Unprotected vaginal or rectal sex
- Sharing injection drug equipment (e.g., needles)
Can HIV be passed from mother to child?
- Yes, during pregnancy, childbirth, or breastfeeding.
- It is called mother-to-child transmission or vertical transmission.
How often does the CDC recommend HIV screening for individuals aged 13–64?
- At least once for all patients in this age group.
Who should receive annual HIV testing?
- Patients with a history of sexually transmitted infections (e.g., syphilis, gonorrhea)
- Hepatitis
- Tuberculosis
- And those engaging in high-risk activities.
What are considered high-risk activities for HIV transmission?
- Sex with multiple partners or with someone whose sexual history is unknown
- Men who have sex with men
- Anal or vaginal sex with someone infected with HIV
- Sharing drug injection equipment (e.g., needles, syringes)
What are symptoms of acute HIV infection?
- Non-specific flu-like symptoms such as fever, myalgia, headache, lymphadenopathy (swollen lymph nodes), pharyngitis, and rash.
Why can patients become asymptomatic after the initial HIV phase?
- Because the antibody response takes time to develop (weeks to months), and although symptoms fade, the virus continues to replicate and can still be transmitted.
When is AIDS diagnosed?
- When the CD4 count is less than 200 cells/mm³ or
- An AIDS-defining condition is present.
What are examples of AIDS-defining conditions?
- OI’s
- Several cancers including Kaposi’s Sarcoma
- HIV wasting syndrome
What is HIV wasting syndrome?
- A condition with loss of fat tissue (lipoatrophy), muscle mass, appetite (anorexia), and diarrhea.
What drugs can stimulate appetite in HIV wasting syndrome?
- Dronabinol (Marinol, Syndros) – cannabis-related
- Megestrol – a progestin
What does initial HIV diagnostic testing involve?
- Screening for HIV antibodies and/or antigens.
- Followed by a confirmatory test that distinguishes HIV-1 from HIV-2
- A nucleic acid testing detecting HIV RNA(viral load) may also be used
When can antibodies be detected after infection?
- In most people, approximately 4–12 weeks after infection.
what is the Diagnostic testing algorithm in HIV
- Initial screening: HIV-1 & 2 AG/AB immunoassay → test for p24 AG and/or HIV-1/2 AB
- If positive → Confirmatory test HIV 1 & 2 AB differentiation immunoassay
- Indeterminate or negative → HIV nucleic Acid test: quantifies viral load
- Positive → HIV diagnosis and subtype confirmed
what is the name of the over the counter HIV test?
- The OraQuick, an In home HIV test that detects the presence of HIV antibodies and provides immediate results
- Individuals with a positive result must follow up with a confirmatory lab test
how does the OraQuick test work?
- The upper and lower gums are swabbed with a test stick and then inserted into a test tube
- After 20 min the result can be read
- testing sooner than 3 months after an exposure can lead to a false negative due to a lag in antibody production
- 1 line = negative
- 2 line = positive
What happens during the binding and attachment stage of HIV replication?
- HIV attaches to a CD4 receptor and a co-receptor (CCR5 and/or CXCR4) on the surface of the host CD4 T cell