HIV Flashcards
What is HIV?
Human immunodeficiency virus
ssRNA retrovirus
What cells does HIV infect?
Cells with CD4 receptor
- T helper lymphocytes
How does HIV replicate?
Virus binds to CD4 receptor + coreceptor
Virus penetrates cell + empties its contents into cell
Reverse transcriptase converts ssRNA -> dsDNA
Integrase combines viral DNA with host DNA
Viral DNA codes for protein
Viral protein forms immature virus
Immature virus pushes out of cell
Protease cuts viral proteins = mature virus
How is HIV transmitted?
Contact of infected bodily fluid with mucosal tissue/blood/broken skin
What are the stages of HIV infection?
Primary HIV infection Stage 1 Stage 2 Stage 3 Stage 4 / AIDS
Are there any symptoms in primary HIV infection?
Asymptomatic
What is the CD4 count in primary HIV infection?
Normal
Are there any symptoms in stage 1?
Asymptomatic
What is the CD4 count in stage 1?
> 500
Are there any symptoms in stage 2?
Mild
What is the CD4 count in stage 2?
<500
Are there any symptoms in stage 3?
Advanced
What is the CD4 count in stage 3?
<350
Are there any symptoms in stage 4?
Severe
AIDS defining
What is the CD4 count in stage 4?
<200
What are the symptoms of an acute HIV infection?
Fever Weight loss Mouth sores Myalgia Headache Lymphadenopathy Rash N+V
What conditions are associated with severe HIV?
CMV infection
Oral candidiasis
PCP pneumonia
HPV
What factors affect HIV transmission?
Type of exposure
Viral load in blood
Condom use
Breaks in skin
What are the tests for HIV?
Serology
PCR
Rapid tests
What is tested for in serology?
HIV antigen
HIV antibody
What is tested for in PCR?
HIV nucleic acid
What is tested for in rapid test?
HIV antibody
What is used to treat HIV?
Anti-retrovirals
What are the aims of HIV treatment?
Undetectable viral load Reconstitute CD4 count Reduce general inflammation Reduce risk of transmission Normalise lifespan
