HIV Flashcards
Name three bodily fluids associated with HIV transmission, what routes can HIV be transmitted?
Vaginal fluid, semen, breast milk
- Sexually; anal sex highest risk
2, Vertical transmission - IDU: HIV can live in a used needle for up to 42 days
- Transfusion via blood products and organ/tissue transplants
What are the chances of an HIV positive mother passing HIV onto her child if she’s received appropriate medical intervention?
Less than 1%
When can an HIV mothers have a normal vaginal delivery and will the baby be given?
If she’s had treatment to suppress the virus and the baby will receive post-exposure prophylaxis
Which types of exposure has the highest estimated risk of HIV transmission?
Receptive anal intercourse
Name 5 other factors that increase the risk of transmission
- A high plasma HIV viral load (more virus around = more infectious)
- Breaches n the mucosal barrier that make HIV access easier; mouth, genital ulcers, trauma, menstruation or bleeding can facilitate transmission
- Ejaculation
- STIs enhance HIV transmission
- Non-circumcision (the inner surface of the foreskin is rich in HIV receptors)
What comprises post-exposure prophylaxis (PEP)?
28 days of HIV therapy to reduce the risk of acquiring HIV from the incidence
What happens when HIV enters the body?
HIV accesses cells via the CD4 receptor and uses reverse transcriptase to make a DNA copy of the RNA genome, which integrates into the host’s DNA. During replication complete virus particles are formed and erupt from the cells.
There is progressive damage to the immune system leading to severe immunodeficiency (primarily depletion and impaired function of CD4 T lymphocytes), opportunistic infections and death
Name two things that HIV induces that are likely to contribute to CD4 lymphocyte loss
Apoptosis and inhibition of CD4 lymphocyte growth
Describe the natural history of HIV in the body after initial infection
- Acute seroconversion: occurs in 50% of people infected within a few weeks of the initial infection and marks the period of time where HIV antibodies grow and are detectable. There is a drop in CD4+ count and a rapid increase in HIV RNA copies and people are extremely infectious at this stage. Often they experience flu-like symptoms; fever, rash, sore throat, myalgia and headache and less commonly meningitis, encephalopathy and neuropathy
This is followed by a partial immune response (an attempt to cure). There is a slight CD4 increase and a drop in HIV RNA copies that falls to a set point which varies from person-person - if it falls to a low setpoint there is likely to be rapid CD4 decline afterwards, but if it falls to a high set point the CD4 decline is likely to be slower
- Asymptomatic HIV infection: can last a few years-decades, people may be asymptomatic or have few symptoms (a period of ‘clinical latency’). A steady decline in CD4 T cells
- AIDS/acquired immunodeficiency syndrome: is the final stage of the HIV infection but doesn’t occur in everyone infected. The majority of people (70-90%) will develop symptoms (once their CD4 count has reached a low point and immune system is damaged); this begins with constitutional symptoms like tiredness, weight loss and progresses to opportunistic diseases (at this point, the person has AIDS) which can lead to death
Name 4 symptoms that can occur in an acute HIV infection
Fever, sore throat, myalgia, malaise
What kinds of opportunistic infections are you likely to start experiencing as your CD4 count continually drops?
Beginning with infections like thrush, can progressively acquire TB, pneumonia, toxoplasmosis and continuously worse infections (that wouldn’t affect those with a healthy immune system as much)
What is the highest age group living with HIV in the UK, what is the highest population?
Which ethnicities of gay/bisexual men and heterosexual men are predominantly living with HIV in the UK?
35-49 yrs old, gay and bisexual men
Ethnicities:
Gay and bisexual men: white
Heterosexual: black African
What is the current HIV treatment and how does it work?
3 drugs: 2 nucleoside reverse transcriptase inhibitors and one drug from a different class (i.e; integrase inhibitors, another NRTI or a protease inhibitor) taken once daily
Halts HIV replication by targeting different areas of the replication cycle so the viral load drops, allowing the CD4 count to grow
What are the benefits of HAART (highly active antiretroviral therapy) for the individual and the population?
Individual: increase life expectancy and by reducing the amount of virus in the blood you reduce the risk of transmission
Population: save health care costs, reduces the overall transmission rate
What did the START study reveal?
A large randomized control trial that revealed that those who started HIV treatment (HAART) immediately had higher CD4 counts (>500) compared to delayed treatments. The immediate HAART also reduced morbidity by 57% and reduced the risk of AIDS by 72%
What classifies having AIDs?
Having an HIV infection that has progressed to the stage where the individual has begun to contract opportunistic infections
What did the treatment as prevention (TasP) studies HPTN 052 and the Partner study reveal?
HPTN 052: Proved early HAART can prevent HIV infection; there was a 96% reduction in transmissions between one HIV positive and one negative mainly heterosexual couples after starting HAART
Partner study: Proved can eliminate transmission on HAART without use of a condom: 0 (condomless) transmissions between homosexual couples with one HIV+ partner after starting HAART
How long can it be between the time an individual starts HAART to the time they achieve viral suppression
1-6 months
Who is recommended to start ART?
ALL HIV+ patients, irrespective of their CD4 count so they may attain a higher life expectancy and eliminate risk of HIV transmission
Name four population groups that are more at risk of having a late HIV diagnosis in the UK
Older age groups, black African, heterosexual men, living outside London
How soon after putting yourself at risk of an HIV infection can you get a reliable test result?
One month
How is HIV tested for?
Serology blood test with p24 antigen in it
What are the British guidelines for testing?
Test at sexual health services, antenatal clinics, drug dependency programs, tests for anyone diagnosed with TB, hep B/C and lymphoma and anyone registering with primary care or having a blood test in A&E
Who is at risk of getting HIV?
*name four groups
- From a high prevalence country
- MSM: men that have sex with men
- History of intravenous drug use
- Diagnosed with an STI
What are 8 ‘indicators’ that an individual may have HIV
(UCPBLHSC)
ALSO, what is one dermatology and one ophthalmology condition that may indicate the need for HIV testing
- Unexplained weight loss
- Chronic diarrhea
- Pneumonia
- Blood disorders; lympho/thrombocyto/neutropenia
- Lymphadenopathy
- Hep B/C
- Shingles
- CIN grade 2>=
Dermatology: kaposi sarcoma
Ophthalmology: cytomegalovirus retinitis
Name four methods to prevent HIV
- Condoms
- Prompt HAART
- Expanded HIV testing
- Use of PreP: pre exposure prophylaxis (2 HIV drugs in one tablet), offers almost 100% protection)
Which study indicated the beneficial use of PreP?
The PROUD study; concluded that the risk of an HIV infection was reduced by 86% for MSM
Name three current important issues in regards to those living with HIV
- Adherence to drugs
- Routine lab tests and drugs can have adverse metabolic impacts (i.e on lipids, inhibition of tubular secretions of creatinine, unconjugated hyperbilirubinaemia)
- Drug-drug interactions with HIV treatments
In a history taking, what 8 factors would need to be specifically addressed in an individual with a suspected HIV infection?
- Risk assessment
- Evidence of a possible seroconversion in the past
- Systemic inquiry
- Previous sexual health/HIV check
- PMH
- FH
- SH
Name five other factors that would need to be considered in a thorough risk assessment
- MSM
- IDUs and their partners
- Involvement in sex industry/sexual assault
- HIV status of mother
- History of blood transfusions
On a physical examination on someone with suspected HIV, what are five things you might specifically focus on?
Oral lesions, lymphadenopathy, skin manifestations, gait and mental score test
What are some investigations that could be offered to a patient with suspected HIV?
- Blood tests; routine blood test (FBC, renal function, etc), CVS risk bloods (blood glucose, lipids), Infection screen, Initial HIV test and confirmatory test
- Imaging; CXR
What are four things that should be considered and explained to a patient about to be tested for HIV? How should their consent be attained?
Consent is verbal
- Confidentiality
- 3 month window period: a confirmatory test 3 months after exposure is recommended as 5% take this long to show positive results
- Financial implications
- Positive and negative implications; i.e social support
What is aspergillosis and what is its relevance to HIV? What are some potential ways it can be diagnosed and how is it treated?
A life-threatening opportunistic disease usually occurring in advanced stages of HIV. It is any illness caused by the fungus aspergillus when it colonizes the host. It can cause severe respiratory disease and potentially fatal full-body infections (especially in immunocompromised individuals)
Diagnosed on history, symptoms, X-rays, fungal growth and biopsies
Treated with antifungal medication (voriconazole)
