HIV/AIDS Flashcards
What is the origins of HIV?
Early 1980’s young gay men came to hospital with unusual infections for their ages. It then spread (primarily in Africa).
How was HIV discovered?
Taking viral particles from a swollen lymph node of a patients and using electron microscopy to diagnose it as a retrovirus
What group of retroviruses is HIV a part of?
Lentivirus which are slow and complex retroviruses
What is the baltimore classification of viruses?
No viruses make their own proteins and so virology comes from the struggle of viruses to make their own protein
What is the HIV-1 Replication cycle
HIV transforms its RNA into DNA and then places this into the host cells genome. This is then transcribed into mRNA and the host cell makes this into proteins.
What animals did HIV come from and the two different viruses?
HIV 1 and HIV 2
chimpanzees
How did the first person get HIV and how did it spread?
During the congalese war there was an increase in bushmeat and during the killing of chimpanzees some blood/blood mixing occured by accident. This then spread due to colonization, medical treatment, sex work, urbanisation etc.
How is HIV transmitted?
Fluid to fluid contact although half of HIV patients did not get HIV through the most at risk groups e.g. sex workers, drug users
What is the clinical course of HIV?
CD4+ T cells are high during the first few weeks of infection leading to no symptoms or minor flu like symptoms.
After a few weeks the set point is hit and the body produced anti-HIV CTL. This is were clinical latency becomes a thing as many people do not know they have the virus.
Eventually however, CD4+ T cells continue to drop, so low you start experiencing symptoms.
What are clinical features of HIV?
Acute primary infection syndrome - FLu-like illness, high leves of virus replication until brought under immune control.
Asymptomatic infection - no outward signs of disease by CD4+ T cells decreasing and active viral infection
Symptomatic HIV infection and AIDs - immune system stops functioning and death can occur
Oppertunistic infections common in HIV?
Mycobacterium TB (most common cause of death)
CMV - affects T cell function and can be found in the liver and cause liver damage and neurocognitive issues
Kaposi Sarcoma - causes lesions and tissue damage and was one of the first concerning factor during the original epidemic.
Taxoplasma Gondii - creates lesions on the brain and neurological issues.
What tests are used to diagnose HIV?
Screening test (ELISA)
Western Blot
Course of therapy
How is an ELISA done?
Have HIV antigens sticking to microtiter plate and add patient serum. Any antibodies to HIV will bind. Add another antibody which will stick to antibody 1. Then when you add the final solution this second antibody will cause a colour change indicating presence
How do you do a western blot?
Add antigen to serum gel and it will be split by size. Add antibodies to this antigen so you can identify proteins once ran through an autoradiography = this shows viral proteins in blood
How does PCR work?
Take viral protein and amplify it. This will show how much protein someone has and if treatment is working
