DETROIT — The AIDS virus may be most contagious when people are least likely to know they're infected, researchers say.
Researchers said the Human Immunodeficiency Virus, or HIV, may be up to 1,000 times more contagious during the first two months--when routine AIDS tests are unable to tell whether people are infected.
"The danger is that a person who tests negative and is very active sexually may be more dangerous than someone who has tested positive," said Carl S. Simon, a University of Michigan researcher.
Among homosexual males, the chances of infecting a partner during unprotected sex in the initial 60 days may be as high as 3 in 10, the researchers said Friday.
Routine AIDS tests look for antibodies to HIV. The antibodies don't immediately appear.
The study, in the Journal of Acquired Immune Deficiency Syndromes, is based on a computer simulation using studies of HIV antibodies in blood from more than 8,000 homosexual males from San Francisco and Chicago and of female-to-male transmission in 1,115 military conscripts in Thailand.