(ID)- HIV Flashcards
What type of virus is HIV?
RNA retrovirus
What are the types of HIV?
HIV-1 (most common)
HIV-2 (mainly found in West Africa)
Outline retroviral replication
- Virus binds to a CD4+ on cell surface & fuses with cell
- Virus penetrates & empties into cell
- Viral ssRNA → dsDNA by reverse transcriptase
- Viral DNA integrated into host DNA by integrase
- Viral DNA transcripted during infected cell division
- Viral protein chains assemble & bud out of cell and matures as protein chains are cut by protease
Why does a flu-like illness occur in the first few weeks of infection?
Initial seroconversion
How is HIV transmitted?
- Unprotected anal, vaginal or oral sex
- Vertical transmission
- Mucous membrane, blood or open wound exposure to infected blood or bodily fluid (needles or blood splash in eye)
What are some AIDS-defining illnesses?
Kaposi’s sarcoma
Pneumocystis jiroveci pneumonia
CMV
Candidiasis
Lymphoma
TB
Who is offered HIV screening?
Patients with any risk factors
What is the fourth-generation laboratory test?
Checks for HIV antibodies and the p24 antigen
Window period of 45 days
Can take up to 45 days after exposure to turn positive
What is a point-of-care test?
Check for HIV antibodies, gives result in minutes
Window period of 90 days
What home testing kits can patients at risk of HIV request?
Self-sampling kits (posted to lab, fourth generation tests, antibodies +p24 antigen)
Point-of-care tests (only antibody)
Complete the table
How is HIV treated?
Antiretrovirals
(Given irrespective of viral load of CD4 count)
Genotypic resistance testing of the HIV strain to guide treatment
What are the different classes of antiretrovirals?
Protease inhibitors
Integrase inhibitors
Nucleoside reverse transcriptase inhibitors
Non-nucleoside reverse transcriptase inhibitors
Entry inhibitors
What starting drug regime is given for HIV treatment?
Two NRTIs tenofovir + emtricitabine and bictegravir
Treatment aims to achieve normal CD4 and undetectable viral load
What additional management must be done for HIV patients?
Prophylactic co-trimoxazole for AIDS patients to protect against PCP
Close monitoring of CVD risk factors as patients at higher risk of CVD
Yearly cervical smears as increased risk of HPV and cervical cancer
Vaccinations
How is transmission of HIV during birth prevented?
IV Zidovudine during labour and delivery if viral load is unknown or above 1000 copies/ml
Prophylaxis given to baby
- Low-risk babies (under 50 copies) given zidovudine for 2-4 weeks
- High-risk babies zidovudine, lamivudine and nevirapine for 4 weeks
