Hamilton Health Sciences

HIV Basics

  • HIV is a virus that infects cells of the immune system, which defends your body against disease.
  • The immune cells, called CD4 cells, become infected with HIV preventing them from fighting off infection.
  • HIV infection occurs when enough of the virus from an HIV positive person’s body gets into an HIV negative person’s body.
  • HIV infection can occur when body fluids infected with HIV such as: blood, semen, breastmilk, vaginal fluid, or anal fluid is exchanged during childbirth, needle or drug paraphernalia sharing, or sexual activities.
  • Having a sexually transmitted infection such as herpes, gonorrhea or syphilis can make it easier to transmit or become infected with HIV.
  • HIV infection cannot occur during casual contact such as sneezing, handshakes, or by touching surfaces such as toilet seats.
  • People living with HIV do not have to disclose their HIV status when there is no risk of HIV transmission.  For example, sharing utensils for cooking and eating; kissing; cuddling; etc.

Managing your health: HIV...the basics 


HIV transmission: an overviewImmunizations-vaccinations
Post-exposure prophylaxis
Pre-exposure prophylaxis
Penile circumcision to reduce HIV risk


Hamilton Health Sciences • Hamilton, Ontario • 905.521.2100

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