HIV transmits through three main routes.
  • Sexual contact with HIV infected person.
  • Exposure to infected body fluids (like infected blood) or tissues.
  • From mother to fetus or child
Other ways that HIV can be transmitted
  • Sharing needles when shooting drugs
  • Home tattooing and body piercing
  • Accidental needle sticks
  • Blood transfusions
  • Breast-feeding
Unprotected sexual contact is the major route of spread of HIV infection. (Thanks the Indian culture and family system which discourage free sex lifestyle. The HIV infected population of India is still below 1% when some African countries like Swaziland and Botswana have crossed 38% of total population.)

Sexual contact can be of three types: Vaginal, Anal and Oral.
  • Vaginal sex (penis in the vagina)
  • Anal sex (penis in the anus) involving either men or women
  • Oral sex (mouth on the penis or vagina)
The risk of transmitting HIV is greatly reduced by using a condom.
Sexually transmitted diseases (STD) increase the risk of HIV transmission and infection 4 times because of the genital ulceration and/or micro ulceration; and by accumulation of pools of HIV-susceptible or HIV-infected cells ( lymphocytes and macrophages ) in semen and vaginal secretions.

The body fluids containing HIV include
  • Blood (including menstrual blood)
  • Semen and possibly pre-seminal fluid ("pre-cum")
  • Vaginal secretions
  • Breast milk
It is possible to find HIV in the saliva , tears , and urine of infected individuals, but due to the low concentration of virus in these biological liquids, the risk is negligible.