Although they are often mixed up these two words have different meanings. 'HIV' is the name of a virus, whereas 'AIDS' is a name for a collection of illnesses caused by this virus.

HIV is the acronym for "human immunodeficiency virus". HIV is present in the blood, semen, pre-ejaculatory fluid and mucous membranes (e.g. intestines) of infected people. An HIV infection cannot be cured, but antiretroviral (ARV) treatment can keep the infection under control and thus prevent the onset of the disease, AIDS. HIV-positive people on effective antiretroviral therapy with an undetectable viral load do not transmit the virus during sexual relations.

Modes of transmission:

HIV is most often transmitted during unprotected penetration (i.e. without condom and/or PrEP), particularly anal sex. During the act, the intestinal mucosa is always damaged, making HIV transmission easier. Whether or not ejaculation occurs, penetration without a condom is risky for both partners, the penetrating (active) and the penetrated (passive) partner.

Fellatio (oral sex) presents virtually no risk of HIV transmission. A low risk is sometimes considered to exist if the person giving fellatio (sucking) has a large mouth sore in contact with seminal fluid/sperm containing large quantities of HIV. These situations are extremely rare; if your mouth is healthy, you can consider fellatio to be HIV-safe. The person receiving the blowjob runs no risk of contracting HIV.