Describe the virus that causes AIDS

HIV is a retrovirus 

ssRNA virus, enveloped

Viron contains 3 enzymes: reverse transcriptase, protease, and integrase

HIV changes rapidly

HIV evolved from a benign simian (monkey) virus into a human-killer in the early 1930s. But it stayed in remote Africa until jet travel, big cities and sexual revolution spread it worldwide.

SIV chimpanzee

How is HIV transmitted?

1. Sex- anal, vaginal, oral

2. Parenteral- IV drug use, needlesticks, transfusions

3. Perinatal- Mother to fetus- in utero

25-33% of untreated HIV+ pregnant pass infection to baby

Can be reduces to 1% with anti-HIV drugs

What opportunistic infections occur in AIDS patients?

Diseases by MO that normally live in or on the body without causing disease to normal people

Supression of the immune system allows the harmless to become harmful.

Caused by viruses, bacteria, fungi, and protozoa

Caused by over 100 mo

Can become systemic

Blood test for antibodies reactive to HIV

Antibodies are detectable within 6 to 18 wks

Newer oral test- detects antibodies in crevicular fluid

Window period- people dont produce detectable antibodies for 6 wks to 1 yr after infection. False negative HIV tests, dangerous time when people may infect others

Later the viral load is monitored

Practice Safer Sex. 

Condoms

Currently made from 3 materials: latex, plastic, lamb skins

1 in 140 condoms break

dont prevent HPV (warts)

dont use oil based lube with latex

Gloves

Gowns, masks, and goggles

Careful handling of needles

disinfection with 1:100 bleach dilution

preventive treatment after exposure

He had HIV and Leukemia

He got a bone marrow transplant form a donor that didnt have the coreceptor

His HIV levels have been undetectable for 30 months

5-10% symptom-free for 15 years or more without antiviral drugs, T4 cells about 600/uL

Involves host and viral factors:

1. High level of responsive cytotoxin T8 cells

2. mutant CCR5 coreceptor gene- more common in caucasians of European descent

3. Defective virus