3. HIV and AIDS Flashcards
What type of virus is HIV?
Retrovirus
How many types of HIV are there?
HIV1 and HIV2
What is the counterpart of HIV2 called?
SIV- species of retrovirus found in non-human primates, found in sooty mangabey animals
What is the evidence that HIV causes AIDS?
HIV fulfils Koch’s postulates for infectious disease as a cause of AIDS.
- you can isolate the agent
- there is an epidemiological association between the infection and development of AIDS
- transmission pathogenesis- you can transmit the infection by injecting it into another organism
Which group of people have the highest risk of HIV?
Sex workers, gay men, people injecting drugs
What does a HIV molecule contain?
gp120, gp41, p24, p17, 2 copies RNA, integrase. reverse transcriptase
What is the mechanism of infection of HIV?
- gP120 attaches to chemokine of CD4 cells
- This causes the virus to merge its envelope with the cellular membrane which will enter the CD4 cell
- The virus will disassemble and RNA will be converted to DNA by reverse transcriptase
- Integration of viral DNA into host DNA by integrase
- Transcription by host RNA polymerase
- Assembly
- Viral budding
What are examples of HIV treatment?
Entry inhibitors
Integrase inhibitors
Protease inhibitors
Portmanteau inhibitors- both RT and integrase inhibitors
Reverse transcriptase inhibitors- nucleoside-analog RTI’s, nucleotide analogue RTI’s, non-nucleoside RTI’s
How is HIV transmitted?
Through exchange of blood or bodily fluids, sexual contact, injection, perinatally
What is the first stage of HIV infection?
Primary HIV infection
What is the second stage of HIV infection?
Occurs 3-6 weeks after primary HIV infection
- Includes acute HIV syndrome mononucleosis-like, plasma viremia
What is the third stage of HIV infection?
Occurs 1 week to 3 months after plasma viremia
HIV-specific immune response, seroconversion
Seroconversion is when the antibodies start appearing in the blood.
What is the fourth stage of HIV infection?
Occurs 1-2 weeks after seroconversion
Clinical latency, decline in CD4 cell count, PGL
What is PGL?
Persistent generalised lymphadenopathy- if there is no treatment for this, after 10 years you will get AIDS, then 2 years later will die.
What is the 5th stage of infection?
Occurs 10 years after PGL
Get clinically apparent disease, AIDS-defining illness, Aids-related complex
What is the final stage of infection?
Occurs 2 years after ARC
You get death from AIDS.
What is the normal CD4 T-cell count?
800-1050/mm3 with a range of 2 standard deviations of approximately 500-1400mm3
What is the normal total blood lymphocyte count?
530-2780