Recent research explains why treating gonorrhea has grown more difficult.
Scientists from Harvard University, the Centers for Disease Control and Prevention (CDC) and other institutions found that using fluoroquinone antibiotics led to the rise of drug-resistant strains of gonorrhea.
"Talk with your doctor about gonorrhea treatment."
The use of various drugs to treat conditions other than gonorrhea contributed to the growth of the multi-drug resistant N. gonorrhoeae strains, said Dr. Edward Goldstein, Senior Research Specialist at the Department of Epidemiology at Harvard School of Public Health.
Gonorrhea, a sexually transmitted disease caused by a bacterium, is the second most common reportable infection, according to CDC. More than 700,000 people in the U.S. get new gonorrhea infections every year and less than half of these infections are reported.
The organism that causes gonorrhea has grown resistant to antibiotics. The only antibiotic that’s currently given to treat gonorrhea is a cephalosporin-based combination therapy.
To understand why the organism that causes gonorrhea grew resistant to antibiotics, scientists looked at use of the antibiotic ciprofloxacin from 2002-2007, gathered from the Gonococcal Isolate Surveillance Project. Ciprofloxacin is a synthetic form of fluoroquinolones, an antibiotic drug class, that was approved by the Food and Drug Administration in 1987.
The CDC stopped recommending fluoroquinolones for gonorrhea treatment in 2007.
The researchers found that fluoroquinolone-resistant strains spread in the U.S. in the late 1990s, especially among men who have sex with men, compared to heterosexual men.
The authors say that ciprofloxacin-resistant gonorrhea infections were more prevalent in men who have sex with men, particularly when an increase in the spread of strains also resistant to the antibiotics penicillin and tetracycline occurred.
The use of various drugs to treat gonorrhea and other conditions contributed to the growth of ciprofloxacin-resistant strains, reports the study.
Travel was not a contributing factor to the spread of multi-drug resistant strains, said Goldstein. He notes, “It’s possible that during the early stages of the growth period when resistance levels are low, acquisition through travel does contribute to the rise in resistance levels, as can be seen for from our analysis for heterosexuals.”
Another reason that may explain the spread of antibiotic-resistant gonorrhea strains: “Other studies have suggested that certain mutations that [are resistant] to ciprofloxacin can make those strains more fit than ciprofloxacin [treatable] strains,” Goldstein said. Those resistant strains were successfully transmitted from person to person, which explains why they became more common.
Several factors have probably contributed to multi-drug resistant gonorrhea strains, he notes. “These factors must be examined further before public health recommendations, such as additional screening for asymptomatic gonorrhea, could be considered,” said Goldstein.
This study was published online in the journal Emerging Infectious Diseases.