How does HIV spread?
How does HIV spread?
HIV is not transmitted by:
- kissing on the lips – the spread of the virus through saliva during kissing has not been confirmed
- mosquitoes or other biting insects – even if the virus gets into a mosquito or other blood-sucking or biting insect, it cannot replicate inside the insect or infect it
- taking part in sports activities with an HIV-positive person – there is no evidence for this
- having everyday contact with friends, at school or at work – no-one can become infected by shaking hands, hugging, using the same toilet or drinking from the same glass as someone who is HIV-positive
- coughs and sneezes – HIV is not airborne
- eating, drinking or using utensils that an HIV-positive person has used.
HIV can be transmitted through:
- the bodily fluids of infected people, such as blood, breast milk, semen and vaginal fluids.
HIV can also be transmitted from mother to child during pregnancy, childbirth and breastfeeding.
Sexual transmission. HIV can be transmitted through penetrative sex. Statistically, anal sex is 10 times more likely to result in infection than vaginal sex. If a person has a sexually transmitted infection, especially if it is accompanied by ulcers or discharge, the risk of transmitting or acquiring HIV during sex is on average 6 to 10 times higher.
Transmission through shared needles and syringes. Repeated use or sharing of needles or syringes poses a high risk of HIV transmission. For people who inject drugs this risk can be reduced by consistently using new disposable needles and syringes or by properly sterilizing reusable needles/syringes before use. To reduce the incidence of transmission in health-care settings, health-care workers should take special precautions.
Mother to child transmission. A child can get HIV from his mother during pregnancy, childbirth and breastfeeding. In general, the risk of mother-to-child transmission of HIV before and during childbirth is 15 to 30 per cent. After childbirth, an HIV-infected mother can pass the virus to her baby while breastfeeding. If the mother receives antiretroviral therapy during pregnancy and breastfeeding, the risk of HIV transmission to her baby is very low.
Transmission through blood transfusion. The risk of HIV infection is extremely high (over 90 per cent) if contaminated blood and blood products are used for transfusion. Blood safety considerations require screening of all donated blood for HIV and other blood-borne pathogens and proper donor selection.
In addition, there is a risk of HIV infection from sharing non-sterile instruments for tattooing and body piercing, using another person's shaving equipment, transplanting organs and tissues from an HIV-infected donor, and using non-sterile medical instruments in medical care.
