S1 - Human Immunodeficiency Virus Flashcards
Where did HIV come from?
It is a zoonotic disease that originated in non-human primates as SIV.
When was HIV first reported in the U.S.?
1981
What populations are especially at risk for HIV transmission?
Intravenous drug users
Homosexual men (44x higher risk than heterosexual men)
Impoverished women (Especially those that have little sexual control in their relationships)
Prostitutes
Healthcare workers (Due to needle sticks and accidental fluid exchange)
African-Americans, Asian-Americans, and Pacific Islanders also experience higher rates of HIV in the US than is found in other ethnic groups (Likely from a socioeconomic or stigma-related disparity).
What does it mean that HIV is a retrovirus?
It means that, upon infection, the virus (RNA) is transcribed (By reverse transcriptase) to DNA and inserted into the host genome after infection. This makes it very hard to treat as it becomes part of our own DNA!
What does it mean that HIV is a lentivirus?
It replicates slowly. There can be long incubation and latency periods between infection and symptoms
How does HIV spread?
What is seroconversion?
HIV spreads via bodily fluids such as blood, blood products, semen, rectal or vaginal fluids, or breast milk.
Seroconversion is when the immune system first begins producing antibodies against HIV. This usually happens a few weeks after the initial infection.
What type of human cell is preferentially infected by HIV?
What are the initial signs/symptoms of infection?
The virus preferentially infects CD4+ Helper T-cells (A type of white blood cell).
Upon initial infection, there are acute symptoms which are typically flu-like.
When has an HIV infection officially advanced to AIDS?
When CD4+ Helper T-cell count below 200/ml (normal counts are 500-1500 per ml).
What are some of the rare infections that typify AIDS (Due to decreased host immune response)?
- Pneumocystic (fungal) pneumonias
- Pneumonia due to cytomegalovirus, toxoplasmosis, herpes simplex, or gastrointestinal protozoa
- Some patients develop a rare form of cancer called Kaposi’s sarcoma. The cancer is caused by Kaposi sarcoma herpesvirus (KSHV) that inserts its genes into the host (Kaposi’s sarcoma is 20,000 times more common in AIDS patients than in the general public).
What is ART/ARV? Do they fully cure HIV?
Antiretroviral Therapy
They do not fully cure the disease; they only keep the viral load down.
What is an HIV superinfection?
When an HIV-infected patient on ARV becomes infected with an additional strain of HIV (Double HIV infection).
What is vertical HIV transmission?
Transmission from an infected mother to her child.
Transmission can occur in utero, during delivery, or through breastfeeding. Breastfeeding is the most common type of transmission from mother to child.
How is HIV different in children than adults?
More recurring opportunistic bacterial and viral infections, (but they are less likely to develop Kaposi’s sarcoma) more rapid disease progression as well
How can vertical HIV transmission be prevented?
A special ARV regimen (Highly effective).
The Pediatric AIDS Clinical Trials Group (PACTG) 076 AZT regimen is a series of ARV drugs given in different amounts during pregnancy, delivery and just after birth to prevent transmission of HIV to a child.
What are a few general methods by which to prevent HIV spread?
Condom distribution
Education
Prophylactic ARV treatment (reduces transmission by 60-80%)
Needle exchange programs
Male circumcision
