A person can contract HIV through the transfer of certain bodily fluids, such as semen, vaginal fluid, pre-ejaculate, breast milk or blood. Bodily fluids that do not spread the virus include sweat, saliva, urine and tears.
HIV can affect anyone regardless of age, race, gender or sexual preference; however, some people are at a higher risk of getting the disease than others. Sexual intercourse is the primary mode of transmission, but HIV is also transferred through contaminated needles and from an infected mother to her baby at birth or through breast milk. In developed countries, such as the United States, there are strict laws for blood screening that largely eliminate transmission through blood transfusion.
There is no danger of contracting HIV through casual contact, the air or from insect/animal bites.