HIV Flashcards
What does HIV stand for?
Human Immunodeficiency Virus
How is HIV transmitted?
- Unprotected sexual intercourse: Increased risk if receiving, or trauma
- Mum to child transmission: can pass on in delivery or breastfeeding if uncontrolled/undiagnosed
- IVDU
- Occupational exposure:needle stick or mucosal exposure
- Blood transfusion: products screened now since 80s
What does HIV do?
- HIV binding and integrating in human DNA can take 3-5 days after exposure
- HIV virions budding out destroys the hosts CD4 T lymphocytes
What is the epidemiology of HIV?
Prevalent in:
- Gay and bisexual men
- Black african men
- Black african women
- People born outside the UK
What is seroconversion?
- Time period during which a specific antibody develops and become detectable in the blood
- After seroconversion occurs, disease can be detected in blood tests for the antibody
What is one measurable HIV antigen called? What is detected first, antigen or antibody in HIV after exposure?
- Called p24 antigen
* p24 Ag detected before HIV ab following exposure
What are the stages of HIV presentation?
- Primary HIV
- Asymptomatic stage
- Symptomatic Stage
- Advanced HIV
During the primary stage of HIV, what happens to the HIV plasma viral load and the CD4 count?
- Viral load goes up
* CD4 count goes down
During asymptomatic stage of HIV, what happens to the HIV plasma viral load and the CD4 count?
- Viral loads goes down after primary stage
* CD4 count rises and stays stable (lower than normal but higher than was before)
During late stages of HIV, what happens to the HIV plasma viral load and the CD4 count?
*Viral load dramatically goes up
*CD4 count drops significantly
(Opportunistic infection occurs)
When does the primary HIV infection occur? What happens? HIV test reveals?
- Diagnosis within 6months of exposure
- Recent negative HIV test supports diagnosis
- Symptoms begin 2-6weeks after infection, lasting 5-10days
- Symptoms: fever, pharyngitis, lymphadenoapthy, rash
- HIV test revels: positive p24 Ag and negative Ab
When does the asymptomatic stage of HIV infection occur? Lasts? How do you tell?
- After primary infection
- Lasts 5-10years
- only way to tell is by having HIV test
- although asymptomatic, on-going viral replication cause immune system damage
What are the presentations possible in the symptomatic stage of HIV infection?
Non-specific:
*persistant lymphadenopathy, fever, myalgia, diarrhoea
Skin lesions:
*folliculitis, multi-site herpes zoster, myalgia, diarrhoea
Oral lesions:
*Candidiasis, oral hairy leukoplakia
Recurrent bacterial infections:
*pneumonia, impetigo
Abnormal blood results:
*thrombocytopenia, lymphopenia
What happens in advanced HIV? How does it present?
- Linked to low CD4 (T lymphocytes)
* predisposes patients to opportunistic infections and certain cancer e.g. B cell lymphoma
What investigations and monitoring should be done for a HIV patient?
Routine:
*U&Es, LFTs, FBC, lipid/bone profile, glucose
Serology:
*Hep A, B (SurfaceAg and core Ab), Hep C, syphilis
HIV viral load:
*Informs of disease progression rate, and monitors treatment response
CD4 cell count
*Main indicator of risk of opportunistic infections
How is HIV treated?
*Treatable chronic condition, not curable
*Highly active antiretroviral therapy (HAART)
=3 different drugs in combination
*Patient commitment essential, good adherence needed
How well are HIV drugs tolerated?
Generally very well
What drugs interact and affect HIV medication?
*Steroids
*Statins
*Anti-anxiety/sedative
*Anticoagulants
*Chemotherapy
*Anti-TB
*Recreational drugs
*Antacids and multivitamins
(Liverpool drug interaction checker)
When is standard HIV testing done?
- Test through opt out screening: Sexual health clinics, antenatal screening
- Mandatory screening: blood and organ donation
- Should test if in region of high HIV prevalence i.e. >2/1000
- Anyone with clinical indicators
What is the window period for HIV testing?
- p24 antigen detected 2-4weeks after exposure
- HIV antibody present 4-8weeks after exposure
- 4th generation test (Ag/Ab) detect most infections at 4weeks
- 3rd generation test window period 12 weeks
What HIV tests are available?
- Rapid point of care test =bedside test (like blood glucose test)
- Blood test sent off (v. accurate but not instant result)
What is used for HIV prevention?
- Barrier contraceptive, condoms
- PrEP (Pre-exposure prophylaxis)
- PEPSE (Post Exposure prophylaxis)
What should be done following a positive HIV result?
- Assess ongoing need for psychological support
- Explain HIV
- Explain ways it can be transmitted
- refer to HIV specialist clinic
- Explain anonymous partner notification
What is PrEP? Used for?
- Pre-exposure prophylaxis
- Given to HIV negative people
- Taken before, during and after sex
- Can be taken daily, or around sexual activities
