HIV may be transmitted from one person to another by:
- Unprotected heterosexual or homosexual intercourse (horizontal transmission). This includes rape or sexual assault.
- Crossing from a mother to her fetus or newborn infant (vertical transmission).
- Using syringes, needles or blades which are soiled with HIV-infected blood. This includes syringes and needles shared by intravenous drug abusers.
- Accidental injuries in health care workers (a needle, lancet or blade contaminated with HIV-infected blood). HIV may also be able to enter via a skin lesion (cut or open wound).
- A blood transfusion with HIV-infected blood or other HIV-infected blood products such as factor VIII in haemophiliacs. This is very rare in South Africa as all blood products are screened for HIV.
There is no evidence that HIV can be spread by mosquitoes, lice or bed bugs. HIV infection is not spread by kissing, holding hands or sharing cups or eating utensils. In Africa HIV is most commonly spread between adults by heterosexual intercourse.
In adults HIV is usually spread by sexual intercourse.