Do I need to use condoms after prostate surgery?

I had a nerve-sparing prostatectomy a year ago and can usually get an erection. Do my girlfriend and I still need to use condoms to protect against sexually transmitted diseases even though I no longer ejaculate when I reach orgasm?

Internist Harvey B. Simon, M.D., editor of the monthly newsletter Harvard Men’s Health Watch, responds:

In a word, yes. Even if a man doesn’t ejaculate, sexually transmitted diseases (STDs) can still be passed from one partner to another during sexual activity. Some diseases, such as HIV/AIDS, gonorrhea, chlamydia, and trichomoniasis, are transmitted when infected vaginal or urethral secretions come into contact with surfaces that secrete or contain mucus — the vagina and cervix in women and the urethra in men. That means a man who has had a prostatectomy can become infected if, for example, vaginal secretions from a woman with chlamydia enter his urethra.

Other STDs can be transmitted through skin-to-skin contact from sores, ulcers, or infected skin that looks normal, including genital skin. These STDs include syphilis, genital herpes, and human papillomavirus (HPV), which can lead to genital warts in men and women and cervical cancer in women. Proper use of condoms helps lower the risk of these diseases, though HPV can infect skin not covered by a condom. Latex condoms are best; condoms made from animal tissues do not prevent STDs, so if either partner is allergic to latex, use polyurethane condoms.

Many people infected with STDs do not have any signs or symptoms of disease and aren’t aware that they are passing an infection to their partner. Some people can harbor a virus like herpes and transmit it to their partners even if years have passed since the infection was contracted. And although STDs can be treated, some, including HIV infection and genital herpes, cannot be cured.

The bottom line: it doesn’t matter whether the man ejaculates. Until you are in a long-term, mutually monogamous relationship with a partner who has been tested for STDs and is not infected, always use a condom during sexual activity — and use it correctly. You should be tested for STDs, too, to be sure you aren’t infected. For more information, log on to the Centers for Disease Control and Prevention’s Web site on STD prevention, www.cdc.gov/std.

Originally published April 1, 2009; Last reviewed April 8, 2011