In the Spanish study, researchers in Madrid followed several hundred couples that included one partner who was HIV-positive from 1990 to 2000. Then the researchers narrowed the number to 110 women and 25 men who engaged in unprotected oral sex but wore condoms during other types of intercourse.
The results of the study appear in a recent issue of the journal AIDS.
The researchers, counting both fellatio and cunnilingus, estimated that 19,000 oral sex acts had occurred, and men had ejaculated in 34 percent to 41 percent of the fellatio acts. However, no HIV-negative partners contracted the virus.
Page Shafer says saliva appears to create an environment that is unhealthy for the AIDS virus