HIV Flashcards
What infections are commonly seen in patients with HIV
Oral candidiasis
Kaposi’s sarcoma
PCP (type of pnuemonia)
What is HIV and what cells does it infect
Human Immunodeficiency Virus
It is a retrovirus with ssRNA as its genome which it converts to DNA using the hosts and its own enzymes
It infects cells with the CD4 surface receptor - T-helper lymphocytes
Describe the process by which HIV infects a cell and makes more copies of itself
- Binds to CD4 and a coreceptor (CCR5 or CXCR4). Then virus fuses with the cell
- Virus penetrates and empties its contents into the cell
- Viral RNA convereted to dsDNA by reverse transcriptase
- Viral DNA is integrated into cell’s DNA by integrase
- When infected cell divides, viral DNA is read and long chains of proteins are made
- Sets of viral protein chains come together
- Immature virus pushes out of the cell, taking some cell membrane with it, it then breaks free of the cell
- Protease cuts the protein chains in the viral particle into individual proteins which combine to make a new virus
How is HIV spread
Contact of infected bodily fluids with mucosal tissue/blood/broken skin
E.g. sexual contact, transfusion, contaminated needles, perinatal transmission
What can HIV look like in its acute phase
Glandular fever
What factors affect HIV transmission
Type of exposure
Viral level in the blood
Breaks in the skin or mucosa
What does a HIV serology test look for in the blood
HIV antigen - Ag
HIV antibody - Ab
What does a HIV PCR look for and what is it used for
Detects HIV nucleic acid
Used for follow up and treatment response
What are the types of rapid tests, what do they detect and why do you need to confirm with serology
Types: blood test, oral, in-home tests, postal testing
Detect HIV antibody
Need to confirm with a postive result as you can get a false positive, but negative is accurate
What drugs are used to treat HIV
Anti-retroviral drugs (ARVs)
Where might ARVs work
At virus binding
At reverse transcription
At integration
At virus maturation
What are the aims of HIV treatment
Get an undetectable viral load
Resonstitute CD4 count
Reduce risk of transmission
Reduce general inflammation
Give a good quality of life and normalised lifespan
Why are three ARVs given at a time
To reduce the chance of the virus developing resistance as the virus mutates every 2-3 rounds
What are some ethical dilemmas associated with HIV
Psychological impact of diagnosis
Dealing with stigma
Patient confidentiality vs:
- Health of mother (if pregnant/already a mother)
- Health of unborn child (if pregnant)
- Health of sexual contact
- Health of any children they may have
- Risk to patients/staff at workplace (depending on where they work)
Give some symptoms of acute HIV infection
Fever
Weight loss
Myalgia in muscles
Hepatosplenomegaly
Malaise
Headache
Neuropathy
Lymphadenopathy
Rash
Nausa and vomiting
Pharyngitis
Sores and thrush in mouth
Sores in esophagus
