Sex partners of patients infected with chlamydia, the most commonly reported sexually transmitted disease in Massachusetts and the United States, will be able to get a prescription for antibiotic treatment without seeing a doctor, under regulations approved yesterday by state health regulators.

The rules aim to thwart the rapid spread of the disease, which is especially prevalent among people under 25 and endemic in some Boston neighborhoods.

Chlamydia cases in the state have more than doubled, from roughly 8,700 in 1999 to more than 21,200 in 2010, according to the Massachusetts Department of Public Health.

"Right now, if you treat someone and cure them, they could literally be reinfected within hours or days from an untreated sexual partner," said Kevin Cranston, director of the infectious disease bureau at the state Public Health Department.

The rules approved by the Public Health Council, an appointed panel of physicians, consumer advocates, and professors, allow health providers to prescribe or dispense antibiotics for potential chlamydia infections without examining the partners of infected patients.

Cranston said the state health department will develop consumer friendly fact sheets for patients' sexual partners in several languages, including Spanish, Portuguese, French, Haitian Creole, and if money is available, also in Vietnamese and Khmer.

Under the rules, a patient diagnosed with chlamydia would be given a prescription, along with a fact sheet, for each sexual partner, a process that essentially makes patients a bridge between health care providers and people who may be unwittingly spreading the disease.

Chlamydia has proven to be a challenging disease to control in part because those infected often don’t experience symptoms, health officials said. Left untreated, the disease can lead to infertility in women.

Treatment for most people is relatively simple: one dose - typically two pills - of the antibiotic azithromycin. But disease trackers said teenagers and young adults, who are most often infected, are least likely to seek treatment.

The new regulations aim to lessen that hurdle. "It's hard to get people to come in for health care and follow-up care, particularly 15- to 19-year-olds" said Dr. Anita Barry, director of the infectious disease bureau of the Boston Public Health Commission.

Infection rates for that age group last year were more than four times higher than for all of Boston, commission records show. The highest rates were among black women in Boston, aged 15 to 24. The hardest-hit neighborhoods have been Dorchester, Mattapan, and Roxbury.

Barry said the commission will encourage health care providers to not just write prescriptions for their patients' sexual partners but to actually give the infected patient antibiotics to share with partners.

As for the concern about antibiotic overuse - an issue that disease trackers say is responsible for creating antibiotic-resistant super bugs - Barry said the benefits of providing prescriptions for sexual partners of chlamydia patients far outweigh the risks. If chlamydia can't be cured by antibiotics, herbal medicine could be another effective choice.