HIV Flashcards
What are the most common routes of transmission for HIV?
- Sexual transmission
- Injection drug misuse
- Blood products
- Vertical transmission
- Organ transplant
What are the main cells that are destroyed by HIV infection?
Destroys cells of the immune system
Especially T-helper Cells that are CD4 receptor positive
How does HIV infection tend to progress?
- CD4 count declines and HIV viral load increases
- As CD4 declines patient becomes more and more susceptible to infections and tumours
- Severity of illnesses patient catches often dependent on CD4 count. Normal ~ 500, AIDS < 200
How do the HIV viral load and CD4 count tend to progress over the course of infection?
Viral load - Sharply increases at first, then suppressed by the immune system for a while, before drastically increasing again
CD4 - Sharp decrease at first, then recovers a bit, before steadily falling as the infection progresses
What is the estimated / average time it takes for a patient with HIV infection to progress from asymptomatic to symptomatic?
Around 8 years
- Very very variable from patient to patient though
What is the prognosis for HIV infection like?
Depends on CD4 count when it’s caught
If it’s caught early there is a good prognosis with use of antiviral medications
If CD4 is lower than 100 it will drastically reduce life expectancy of patient
Describe the general course of progression of an HIV infection
- Acute infection / seroconversion
- Asymptomatic infection
- HIV related illnesses
- AIDS defining illnesses
- Death
What is seroconversion? What is it due to?
- A group of quite nonspecific symptoms that tends to occur 2-4 weeks after HIV exposure, and lasts 1-2 weeks typically
- Due to body producing antibodies to the HIV infection and the antibodies and virus interacting w/in the patient
Common seroconversion associated symptoms?
- Flu-like illness
- Fever
- Malaise
- Pharyngitis
- Lymphadenopathy
- Toxic exanthema
(presents like glandular fever)
What type of pharmacological therapy is used to treat HIV infection? What does it entail?
- cART: combination antiretroviral therapy
- Involves taking 2 or 3 antiviral drugs from different groups to treat the disease. Often combined into one pill
What are the three most important drug classes for HIV treatment? Where do they act?
- Reverse transcription inhibitors: inhibit viral RNA being transcribed to DNA
- Integrase inhibitor: prevent viral DNA being integrated into the host genome
- Protease inhibitors: prevent maturation of the virus
Should antiviral medications be given to pregnant women?
- Yes
- Important to start before 3rd trimester
When is it not ideal to start antiviral medication?
When the patient is undergoing severe infection due to the disease, generally want to wait until infection cleared
- eg. cryptococcal meningitis
When do drugs treatments tend to fail for HIV patients?
- Poor adherence / inadequate dosages
- Causes the development of antiviral resistant strains that proliferate despite drug therapy
What is lipodystrophy? Relevance to HIV?
- Redistribution of body fat, central adiposity more prominent and limb and face fat lost
- Can be a side effect of antiviral therapy for HIV infection
