It is a RNA virus/retrovirus

•HIV infects cells of the immune system, called

helper T cells

• This destroys helper T cells / cause their no.

to decrease

• Body is unable to defend itself against

infection

• Virus is unable to survive out the human body

• Semen, vaginal fluids during unprotected sexual intercourse

• Blood transmission via infected blood transfusion / contaminated

syringes

• Mother to baby transmission across placenta / breast milk

• and also having multiple sex partners allows virus to spread more widely

• Anal intercourse increases risk of transmission

• This is because there is less natural lubrication in the rectum, so rectal lining is

easily damaged and virus can pass from semen into blood

•Contact with objects, such as dishes, toilet seats, or doorknobs, used by a person with HIV

•The air or water

•Mosquitoes, ticks, or other insects 

(since virus can stay dormant for years)

result of a compromised

immune system

• Collection of opportunistic

diseases associated with

immunodeficiency caused by HIV =

AIDS

• oral thrush

• pneumonia

• cancers like Kaposi's

sarcoma

• neurogenerative

diseases like dementia

• tuberculosis (TB)

• malaria

• malnutrition

• weight loss

• diarrhoea

• fever

• sweating

• Drug therapy can only slow down the onset of AIDS.

– Zidovudine (similar to the nucleotide base that contains

Thymine) binds to viral enzyme reverse transcriptase and

inhibits it

– Drugs can target viral protease and inhibit it as well

– However, drugs are expensive and have a variety of side effects

• Combination therapy

– Must follow a strict pattern and timing of medication

– If not followed properly, patients may develop strains of HIV

resistant to drugs.

• Use of condoms, femidoms and dental dams

• HIV testing promoted in high-risk groups (e.g. male

homosexuals, prostitutes, injecting drug users, sex

partners)

• Contact tracing = where the person with HIV traces people he/she has put

at risk of infection and that person to provided a HIV test

• Discourage needle sharing

•Donated blood is screened for HIV and heat-treated to kill viruses

• Control mother-to-child transmission using drugs

• HIV+ women of high income countries should avoid breastfeeding to

reduce transmission

– BUT HIV+ women of low/middle income countries advised to

breastfeed bcs milk provides protection against other

diseases and lack of clean water outweigh the risk of transmitting HIV

• But especially high numbers/high prevalence in Africa