QUESTION
If a negative top has sex with a positive bottom without using a condom, what are the chances of the top being infected with HIV. If the top cums inside the positive bottom would the top have a high risk in getting infected?

ANSWER
Without a condom, the published chances of a top getting HIV from a positive bottom is about 1 in 1,666. If a condom is used that risk is greatly reduced.  Several factors can increase or decrease that risk including circumcision status (circumcised tops are less likely to get HIV infection through insertive anal sex) and a current STD. STDs in either partner increase the chance of getting or spreading HIV.

Ejaculation or no ejaculation does not seem to change the risk of the person ejaculating getting HIV infection. Ejaculation is how HIV is transmitted but in men who practice insertive sex (anal or vaginal) getting HIV has to do with the skin of the penis and that’s why circumcised men are protected. Using a condom will drastically improve the safety of anal sex — both safety from HIV and other diseases. Getting checked for STDs consistently and using condoms with plenty of lube is crucial to good sexual health and satisfaction.

To your health,
Dr. K