SEATTLE -- People with chlamydia or gonorrhea are supposed to tell past sexual partners about their diagnosis and urge them to get treatment.
A new study says giving the patients medicine to pass on to their possibly infected sexual partners works even better.
"It decreases those patients' risk of being reinfected, and increases their partners' chance of being treated," said lead study author Dr. Matthew Golden, acting director of the STD Control Program for Seattle and King County Public Health.
The study, published today in the New England Journal of Medicine, tracked 1,860 patients with gonorrhea or chlamydia in the Seattle area. Half were told to contact their current and former sex partners and tell them to get treatment -- the standard procedure.
The other half were given antibiotics to give to their sex partners. No medical exam was required for the partners.
The gonorrhea patients who got medication to give directly to their partners were 73 percent less likely to be infected at their three-month checkup, compared to the control group, and chlamydia patients were 15 percent less likely to be infected.
Researchers said that indicates the sexual partners had successfully gotten treatment, because they weren't re-infecting the original patient. They speculated that the success rate for chlamydia was lower because the antibiotics are less effective, especially for women, than the medication for gonorrhea.
The findings "represent a major advance for the control and prevention of STDs," Drs. Emily Erbelding and Jonathan Zenilman of Johns Hopkins University School of Medicine wrote in an editorial accompanying the article. They noted that the traditional approach "has largely been a failure."
Only about half of partners of people infected with sexually transmitted diseases usually get treatment, Golden said. Overburdened public health departments lack the time and resources to track down patients' past sexual partners.
"We really need a better system," Golden said.
The researchers provided their patients with "partner packets" that included information about allergies and possible side effects along with the medication. Allergic reactions or bad drug interactions could pose a problem, the study acknowledges, but none of the partners in the study reported any ill effects.
The bigger hurdles, researchers said, are state laws or regulations that could prevent patients from delivering prescription drugs to their partners. Only four states explicitly allow this sort of treatment -- in others, the law is vague and doctors may be hesitant to take the risk.
"Overcoming these legal and regulatory barriers may require substantial advocacy and perseverance," Erbelding and Zenilman wrote.
Doctors across the country occasionally give patients antibiotics for their partners, informally and on a case-by-case basis. A 2001 California law makes it legal, at least for chlamydia treatment. A state official said the law seems to be working well, though there's no hard data yet on whether the program has helped curb infection rates in California.
"It's been well-embraced by a lot of providers," said Dan Wohlfeiler, spokesman for the STD Control Branch of the California Department of Health Services. "It's still important to try and get a patient in for an STD check, but this is an additional tool to use when that's impossible."
Chlamydia and gonorrhea are two of the most common sexually transmitted diseases. About 2.8 million Americans are infected with chlamydia each year, according to the Centers for Disease Control and Prevention, and more than 700,000 get new gonorrheal infections each year.