Lecture 3: HIV and AIDS Flashcards
how is HIV spread?
- sexual transmission
- injection drug misuse
- blood products
- vertical transmission
- organ transplant
HIV pathophysiology
- HIV infects and destroys cells of the immune system especially the T-helper cells that are CD4+
- CD4 receptors are not exclusive to lymphochytes- they are also present on the surface of macrophages and monocytes, cells in the brain, skin and probably many other sites.
natural history of HIV infection
- acute infection - seroconversion
- asymptomatic
- HIV related illnesses
- AIDS defining illness (severe infections) occur at CD4 < 200.
- death
what is a normal CD4 count?
CD4 > 500
primary HIV infection signs and symptoms
Typically, individuals with primary HIV infection experience a mild flu-like illness 2-6 weeks post-exposure. Classic presentations include:
- asymptomatic
- fever
- lymphadenopathy
- maculopapular rash (usually on upper chest)
- mucosal ulcers
- myalgia
- arthralgia
- fatigue
what is the most common late stage (AIDS) infection and how does it present?
- Pneumocystitis jiroveci pneumonia
- opportunistic infection
- CD4 cell count usually < 200
- classical history of dry cough and increasing breathlessness over several weeks.
what are the investigations and treatments for pneumocystis jiroveci pneumonia?
- investigations: CXR and induces sputum or bronchoscopy for PCR.
- Treatment: Cotrimoxazole and Petamidine.
- Prophylaxis until CD4 > 200.
HIV treatment
cART
when should cART therapy be initiated in pregnant women with HIV?
before third trimester
why do some HIV treatments fail?
- inadequate potency
- inadequate drug levels
- inadequate adherence
- pre-existing resistance
Nucleoside reverse transcriptase inhibitors side effects
- marrow toxicity
- neuropathy
- lipodystrophy
non-nucleoside reverse transcriptase inhibitors side effects
- skin rashes
- hypersensitivity
- drug interactions
- neuropsychiatric effects
protease inhibitors side effects
- drug interactions
- diarrhoea
- lipodystrophy
- hyperlipidaemia
integrase inhibitors side effects
- rashes
- disturbed sleep
HIV prevention measures
- behaviour change and condoms
- circumcision
- treatment as prevention: VL undetectable = untransmissable
- pre-exposure prophylaxis (PrEP)
- post-exposure prophylaxis for sexual exposure (PEPSE)
