UNIVERSITY PARK, Pa. -- Sexual health research focused on men who have sex with men is lacking, according to health researchers, even in the midst of rising rates of sexually transmitted infections, including HIV, in this population.

According to data from the U.S. Centers for Disease Control and Prevention, three-quarters of syphilis cases, 22 percent of gonorrhea cases and two-thirds of HIV diagnoses in the U.S. occur in men who have sex with men.

A recent study identifies multiple sexual behaviors significantly associated with prevalent sexually transmitted infections, including HIV.

"People participate in a wide range of sexual behaviors -- however, public health research has mainly focused almost exclusively on anal intercourse as the singular sexual behavior of interest among men who have sex with men," said Cara E. Rice, postdoctoral fellow, The Methodology Center, Penn State. "Standard prevention messages are largely about avoiding risky anal sex. Yet many men engage in other sexual practices, and the associations between those practices and sexually transmitted infections have not been comprehensively characterized."

Rice noted that some men, for example, abstain from anal intercourse and engage in other sexual activities because they perceive those practices to be less risky. However, the current study shows that this is not necessarily the case.

In order to increase understanding of the range of sexual behaviors practiced by men who have sex with men and associations with prevalent HIV and STI, Rice and colleagues surveyed 235 men who went to a sexually transmitted disease clinic for care and reported having sex with another man in the past year. The researchers report their results in the current issue of the Journal of Sexual Medicine.

In the sample, 35 percent of the participants tested positive for an STI on the day of the study, and 17 percent had HIV. Men who participated in anal stimulation with a fist or hand in the last three months were nearly five times as likely to be positive for HIV as those who did not report these behaviors. Those who reported enema use had nearly four times the prevalence of HIV as those who did not report recent enema use.

Those who reported fisting, enema use or use of penetrative sex toys were significantly more likely to have chlamydia, gonorrhea or syphilis at the time of the study than those who did not report those practices.

"Public health practitioners need a more nuanced understanding of the behaviors their patients are engaging in," said Rice. "And patients deserve more robust, evidence-based messages about the associations between specific practices and the prevalence of infections."

As far as the researchers are aware, this is one of the first studies to take a comprehensive look at a wide range of sexual behaviors practiced by men who have sex with men and the associations between these behaviors and the prevalence of HIV and STI.

Rice points out that much more research is needed in this area, including further analysis of sexual behavior and STI and HIV occurrence that also looks at drug use, number of sexual partners, and context of and intent behind specific behaviors. Prospective studies are also needed to definitively link behaviors and risk of HIV and STI.

Rice is also a postdoctoral fellow of biobehavioral health at Penn State. Stephanie T. Lanza, scientific director, the Methodology Center, and professor, biobehavioral health, Penn State; Courtney Maierhofer, clinical research assistant, and Abigail Norris Turner, associate professor of internal medicine, both at Ohio State University; Karen S. Fields, sexual health clinic manager, and Melissa Ervin, clinical operations manager, both at Columbus Public Health, also contributed to this research.

The Ohio State University Center for Clinical and Translational Science and the National Institute on Drug Abuse supported this work.