Background Community Acquired Methicillin Resistant Staphylococcus aureus (CA-MRSA) has been found more often among men who have sex with men (MSM) in some studies (USA). This study assesses the prevalence and sexual risk factors for CA-MRSA and methicillin susceptible Staphylococcus aureus (MSSA) colonisation and infection among MSM in Amsterdam, the Netherlands.

Methods MSM attending the sexually transmitted infections outpatient clinic in Amsterdam were invited to participate in this study and divided in two groups: (1) MSM with clinical signs of a skin/soft tissue infection (symptomatic group) and (2) MSM without clinical signs of such infections (asymptomatic group). Demographic characteristics, medical history, sexual behaviour, history of sexual contacts and known risk factors for colonisation with S aureus were collected through a self-completed questionnaire. Swabs were collected from the anterior nasal cavity, throat, perineum, penile glans and, if present, from infected skin lesions. Culture for S aureus was done on blood agar plates and for MRSA broth on selective chromagar plates after enrichment in broth. If MRSA was found, the sex partners of the index patient were invited for screening for MRSA.

Results Between October 2008 and April 2010 a total of 214 MSM were included in the study: 76 into the symptomatic group and 138 MSM into the asymptomatic group. The prevalence of MSSA in the nose was 36% (78/214) and in skin lesions 36% (27/76). The prevalence of MRSA was 0.9% (2/214). Both MRSA cases, one asymptomatic and one symptomatic, were HIV positive. The asymptomatic MRSA carrier had been hospitalised the previous year. None of the four sexual contacts that could be traced were colonised by MRSA. The symptomatic MRSA case had a soft tissue infection in the genital area; in this case also the nasal cavity, perineum and glans penis were positive for MRSA. No sexual contacts could be traced. There were no significant differences in age, sexual risk behaviour, drug use, history or diagnoses of sexual transmitted diseases, circumcision status or hygiene behaviour between those with and without a genital S aureus infection, but those infected with S aureus were significantly more often HIV infected (55% vs 34%; p<0.01).

Conclusion CA-MRSA among MSM STI outpatient clinic visitors in Amsterdam is rare. There were no indications for sexual transmission of MRSA or MSSA in this population.