LEC 10: HIV Flashcards
What is HIV?
Infect and destroys T-helper or CD4 cells. These cells direct coordination of other cells in the immune system to fight infection, without these cells the body loses its ability to fight infection
What are the 3 ways that HIV transmission can occur?
- Sexual contact
- Any unprotected sex - Blood contact
- Sharing needles or occupational exposure - Vertical transmission
- Mother-to-baby during birth or breastfeeding
What bodily fluids can transmit HIV?
- Vaginal fluids
- Anal fluids
- Semen
- Blood
- Breast milk
What are risk factors for HIV?
Risk is risk: HIV does not differentiate who gets infective
- Unprotected sex
- Sex with multiple partners
- Sharing of needles
- Poor access to healthcare
Pathophysiology of HIV
The HIV virus is a retrovirus (contains RNA) & it
utilizes the CD4 cell’s DNA to replicate…which in
turn causes the destruction of the CD4 cell
How dose the initial infection if HIV start?
- Viremia, large amounts of virus in the blood, for a few weeks
- Followed by a prolonged period where viral count remain low without treatment (replicating cells) can last up to 12 years and patient may have no symptoms
- As the virus remains in the body they infect cells with CD4 receptors mainly T-heleper cells; as these destroy the immune system no longer works effectively
Seroconversions/ Acute/ Primary Illness
Most patients who become infected develop flu-like symptoms (called acute retroviral syndrome) typically a few days to a few weeks after exposure to HIV and last 2 to 4 weeks
Chronic HIV Infection
- Early stages
- CD4 T-lymphocyte levels remain high and viral load remains low
- Usually asymptomatic (why people may not be away they are infected) - Intermediate stages
- CD2 T-lymphocyte drops to 200-500 cells/microliter and viral load rises
- Symptoms seen in early stages but worst, persistent fever, frequent night sweats, chronic diarrhea, recurrent headaches, severe fatigue
- Other problems may occurs such as localized infections, lymphadenopathy, thrush, shingles, vaginal candida infections, etc. - Late stages (AIDS)
- Caused by HIV (cannot be infected with AIDS)
- Immune system becomes severely compromised
What are the 3 antibody testing that can be done for HIV detection?
- ELISA screening
- Western blot test
- Point of care testing (rapid testing)
**There is a delay of 2 months after infection before HIV can be detected
What are the tests for monitoring HIV?
- Both test crucial
1. CD4 count: measures the amount present (400+ is considered healthy) - Decrease signals = decreased immune function
- Viral load: measures amount of HIV in the blood
- Measured in copes/mL of blood - It is also possible to test for anti-viral drug resistance
Treatment of HIV
Is a combination of 3 drugs from 2 classes (cART)
- NRTIs, NNRTIs, protese inhibitors, integrase inhibitors, fusion inhibitors, CCR5 entry inhibitors
- Adherence is crucial to achieving optimal response, The virus has the ability to become resistant if in the presence of sub-optimal med levels
- 90 to 95% adherence to prevent resistance (around 2 dose missed/month)
What is the goal for HIV treatment?
Viral suppression, increase or maintain immunity and improve quality and quantity of life
Prognosis of HIV treatment
- Life expectancy near that of those who are HIV negative if treatment started when CD4 grater then 200
- Lower expectancy if injection drug use, starting later, or history of opportunistic infections
Impact of Treatment on HIV Incidence Could be Improved by What?
- Increasing rate of HIV testing
- Offering treatment earlier
- Improving linkage to care
- Improving adherence to treatment
PREP (Pre-Exposure Prophylaixs)
- Daily medication that people can take to reduce chance of getting HIV
- Best to use of you have an HIB-positive partner; you have multiple partners who’s status is unknown or are a drug user who shares needles or equipment
