Diagnoses of gonorrhea among men who have sex with men are apparently rising in the United States. Centers for Disease Control and Prevention (CDC) researchers, in order to determine demographic information, interviewed a random sample of individuals diagnosed with the sexually transmitted infection (STI) in 12 areas across the country between 2010 and 2013. The researchers then used census and Gallup opinion polling data to estimate the respective sizes of the U.S. MSM, heterosexual male, and female populations by age group at the state, county and city levels.

In 2010, there were an estimated 1,169.7 diagnoses of gonorrhea per 100,000 MSM. In other words, about 1.17 percent of MSM contracted the STI that year. This rate rose 26 percent in three years, hitting 1,474.4 diagnoses per 100,000 MSM, or 1.47 percent, in 2013. Looking at MSM according to age bracket, those between 25 and 29 years of age  had the highest diagnosis rate: 3,400 per 100,000, or 3.4 percent.

During the study period, gonorrhea diagnosis rate among MSM was between 10.7 and 13.9 times higher than that of women or heterosexual men.

While the researchers speculate that the rising gonorrhea rates may be indicative of a national trend, they caution that the data in this study is not nationally representative.

Stressing that it is difficult to make broad conclusions about what may be causing the rising rates of gonorrhea among MSM, the CDC speculates that the causes may span social and individual elements, including a high prevalence of infection among what are known as sexual networks, as well as stigma, homophobia and lack of access to health care.

Mark Stenger, MA, an epidemiologist in the CDC’s Division of STD Prevention, says, “Reinfection [of gonorrhea] through having sex again with an untreated partner may contribute to increased incidence, as can exposure to new partners who may not know they are infected (gonorrhea can also infect their throats or rectums without showing symptoms).

“Barriers to accessing health care may also contribute, in that people may not seek care quickly when they suspect they are infected,” he continues, “or even seek care at all if they perceive homophobia, or if they cannot afford care for any reason.”

Lower overall rates of condom use and an increase in the number of sexual partners among MSM could play a role in the shifts in these figures, but the CDC does not have data to support that.

Recent CDC research found that MSM drove a 10 percent rise in U.S. syphilis cases between 2012 and 2013.

According to the CDC, it is unlikely that the use of Truvada (tenofovir/emtricitabine) as pre-exposure prophylaxis (PrEP) played a major role in the rising gonorrhea rates during the study period. Although approved in 2012, PrEP did was not widely discussed in the media or among MSM until late 2013. Its use, which was minimal at that time, has steadily increased during the time since then.

Further, it is unclear whether PrEP is causing MSM to use condoms less, thus putting themselves at greater risk for STIs. No clinical trial of the HIV prevention method has shown that Truvada has led to reduced condom use. Data released about a group of more than 600 MSM receiving PrEP from a clinic in San Francisco, however, showed that 41 percent of the men reported using condoms less since going on Truvada. Half of the group contracted at least one STI during their first year, or partial year, on PrEP. It is important to consider, thought, that information on the risk-taking patterns of this group is limited by that study’s lack of a comparison group of similar individuals who did not use PrEP. So there is no way to know for certain how PrEP actually affected their sexual risk taking.

A major mitigating factor for such increased sexual risk-taking, where STIs are concerned, is that the CDC recommends that men taking PrEP receive STI screening every six months (some prescribers will have people on PrEP test for STIs every three months, the required frequency of an HIV test). Increased screening likely leads to treatment that can ultimately reduce the amount of time an individual spends with an untreated, and therefore infectious, STI.

To read a POZ feature about STI infection prevention, click here.