Transmission

Since the beginning of the pandemic, three main transmission routes for HIV have been identified:-

(1)Sexual route

The majority of HIV infections are acquired through unprotected sexual relations. Sexual transmission can occur when infected sexual secretions of one partner come into contact with the genital, oral, or rectal mucous membranes of another.

(2)Blood or blood product route

This transmission route can account for infections in intravenous drug users, hemophiliacs and recipients of blood transfusions (though most transfusions are checked for HIV in the developed world) and blood products. It is also of concern for persons receiving medical care in regions where there is prevalent substandard hygiene in the use of injection equipment, such as the reuse of needles in Third World countries. HIV can also be spread through the sharing of needles. Health care workers such as nurses, laboratory workers, and doctors, have also been infected, although this occurs more rarely. People who give and receive tattoos, piercings, and scarification procedures can also be at risk of infection.

(3)Mother-to-child transmission (MTCT)

The transmission of the virus from the mother to the child can occur in utero during pregnancy and intrapartum at childbirth. In the absence of treatment, the transmission rate between the mother and child is around 25%.[15] However, where combination antiretroviral drug treatment and Cesarian section are available, this risk can be reduced to as low as 1%.[15] Breast feeding also presents a risk of infection for the baby.