HIV in Canada: A primer for service providers

 

HIV Transmission

Key Points

  • Only five bodily fluids can contain enough HIV to transmit the virus: blood, semen (including pre-cum), rectal fluid, vaginal fluid and breast milk.
  • HIV can be transmitted when one of these fluids from a person with HIV gets into the bloodstream of another person, either through broken skin or the mucous membranes.
  • The two most common ways for HIV to be transmitted are through unprotected anal or vaginal sex and by sharing equipment used to inject drugs.

Only five bodily fluids contain enough HIV to transmit the virus: blood, semen (including pre-cum), rectal fluid, vaginal fluid and breast milk.

HIV can only be transmitted when one of these fluids from a person with HIV gets into the bloodstream of another person, either through broken skin or by passing through the mucous membranes (the “wet” tissues of the body, such as the vagina and cervix, the rectum, and the penis foreskin and urethra).

In Canada, HIV is most commonly transmitted through:

  1. Anal or vaginal sex that is not protected by a highly effective HIV prevention strategy (i.e. condoms, PrEP, or the use of HIV treatment to maintain an undetectable viral load)
  2. Shared equipment used to inject drugs

HIV can also be passed to a baby during pregnancy, childbirth, or breastfeeding (known as perinatal transmission). However, we now know that taking HIV treatment is the best way to reduce the risk of HIV transmission to a baby. Policies such as the offer of an HIV test in pregnancy, free formula programs, and recommended life-long treatment for all people living with HIV have made perinatal transmission extremely uncommon in Canada.  

In the past, some people got HIV after receiving a blood transfusion or organ or tissue transplant. However, Canada implemented HIV screening for all blood donations in 1985.

HIV cannot be transmitted through casual contact with a person who has HIV, or through objects such as toilet seats, doorknobs, or dishes used by a person who has HIV.