A new study in the British Medical Journal shows swingers—straight couples who regularly swap partners, and engage in organized group sex—report higher rates of sexually transmitted infections than prostitutes. Dutch researchers say that those over age 45 are particularly vulnerable, although the group doesn’t get enough attention from health care services, the BBC reports. In the study, researchers looked at the number of patients getting treatment at sexual health clinics in the Netherlands in 2007 and 2008. These clinics have recorded if a patient is a swinger since early 2007. In the study, there were about 9,000 consultations, and one in nine patients was a swinger with the average age of 43. Combined rates of Chlamydia and gonorrhea were just over 10 per cent among straight people, 14 per cent among gay men, less than 5 per cent among female prostitutes, and 10.4 per cent among swingers.