ABCs of STDs

Over 12 million Americans will get a sexually transmitted disease (STD) this year. Most of them won't even know it.

"One of the worst problems with STDs is that many of them don't have symptoms," says Shaparak Kamarei, M.D., USC associate clinical professor of internal medicine. "So you have people spreading the disease to others because they don't even know they have it."

As the name implies, STDs are contracted through sexual intercourse, be it vaginal, anal or oral, Kamarei says. People most at risk for any of the more than 20 identified STDs include those with multiple partners or who don't use condoms for protection.

STDs are caused by bacteria and viruses, she explains. STDs caused by bacteria include chlamydia, gonorrhea and syphilis. These can be treated and cured with antibiotics. STDs caused by viruses include human immunodeficiency virus (HIV), genital herpes and genital warts. One a person has been infected with one of these viruses, there's no way to get rid of it.

"In the case of bacterial STDs, both partners need to be checked and treated before they resume intercourse," Kamarei stresses. "Because if one partner is not treated, he or she will reinfect the other."

Even if a person has no signs of an STD, he or she can still be infected and pass on the disease. Not only are STDs embarrassing, but in women, they can to greater health problems such as cervical cancer, chronic pelvic pain and infertility, Kamarei says.

STDs are most prevalent in young people. Nearly two-thirds of all STDs occur in people younger than 25 years of age.

"Obviously, the best way avoid getting an STD is by not having sex", she says. "The next best thing is maintaining a mutual monogamous relationship with an uninfected partner."