liz@ai.mit.edu (Liz A. Highleyman) (05/29/91)
Blood and semen have the highest amounts of HIV virus. Vaginal fluid has somewhat less, and other fluids (sweat, saliva) have very small amounts. There are cases in which HIV was believed to be transmitted by oral sex on a woman (5 that I know of); I believe in the majority of these the woman was menstruating. Blood cells can be present in vaginal/ cervical fluid for awhile before and after a period, in amounts too small to be visible. Also, the risk of HIV transmission through vaginal/cervical fluid is likely to be greater if the woman has an infection (such as a low grade yeast infection). This is because white blood cells containing the virus may be shed with the fluid (this circumstance is also likely to make a woman more vulnerable to becoming infected with HIV). -Liz