Data from: Low prevalence of methicillin-resistant Staphylococcus aureus among men who have sex with men attending an STI clinic in Amsterdam, a cross-sectional study

Objective: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is common among men who have sex with men (MSM) in the USA. It is unknown whether this is also the case in Amsterdam, the Netherlands. Design: Cross-sectional study. Setting: Sexually transmitted infection outpatient low- threshold clinic, Amsterdam, the Netherlands. Participants: Between October 2008 and April 2010, a total of 211 men were included, in two groups: (1) 74 MSM with clinical signs of a skin or soft tissue infection (symptomatic group) and (2) 137 MSM without clinical signs of such infections (asymptomatic group). Primary outcome measures: S aureus and MRSA infection and/or colonisation. Swabs were collected from the anterior nasal cavity, throat, perineum, penile glans and, if present, from infected skin lesions. Culture for S aureus was carried out on blood agar plates and for MRSA on selective chromagar plates after enrichment in broth. If MRSA was found, the spa- gene was sequenced. Secondary outcome measures: Associated demographic characteristics, medical history, risk factors for colonisation with S aureus and high-risk sexual behaviour were collected through a self- completed questionnaire. Results: The prevalence of S aureus colonisation in the nares was 37%, the pharynx 11%, the perianal region 12%, the glans penis 10% and in skin lesions 40%. In multivariable analysis adjusting for age, anogenital S aureus colonisation was significantly associated with the symptomatic group (p=0.01) and marginally with HIV ( p=0.06). MRSA was diagnosed in two cases: prevalence 0.9% (95% CI 0.1% to 3.4%)). Neither had CA-MRSA strains. Conclusions: CA-MRSA among MSM in Amsterdam is rare. Genital colonisation of S aureus is not associated with high-risk sexual behaviour.

研究目的：社区获得性耐甲氧西林金黄色葡萄球菌（Community-associated methicillin-resistant Staphylococcus aureus, CA-MRSA）在美国男男性行为者（men who have sex with men, MSM）中较为常见，而荷兰阿姆斯特丹地区是否存在类似流行情况尚不明确。
研究设计：横断面研究。
研究地点：荷兰阿姆斯特丹一家低门槛性传播疾病门诊诊所。
研究对象：2008年10月至2010年4月期间，共纳入211名男性受试者，分为两组：（1）74名存在皮肤或软组织感染临床症状的男男性行为者（症状组）；（2）137名无此类感染临床症状的男男性行为者（无症状组）。
主要结局指标：金黄色葡萄球菌（Staphylococcus aureus, S. aureus）与耐甲氧西林金黄色葡萄球菌（methicillin-resistant Staphylococcus aureus, MRSA）的感染及/或定植情况。采集受试者前鼻腔、咽喉、会阴部、阴茎龟头的拭子样本，若存在感染性皮肤皮损则额外采集皮损拭子。采用血琼脂平板进行金黄色葡萄球菌培养，经肉汤增菌后使用选择性显色琼脂平板开展MRSA培养；若检出MRSA，则对其spa基因进行测序。
次要结局指标：通过自填式问卷收集受试者的人口统计学特征、病史、金黄色葡萄球菌定植相关危险因素及高危性行为信息。
研究结果：受试者鼻腔金黄色葡萄球菌定植率为37%，咽喉部为11%，肛周区域为12%，阴茎龟头为10%，感染性皮肤皮损处为40%。在校正年龄的多因素分析中，肛生殖器部位的金黄色葡萄球菌定植与症状组呈显著相关性（p=0.01），与HIV感染呈边际相关性（p=0.06）。共检出2例MRSA感染，患病率为0.9%（95%置信区间：0.1%~3.4%），两株菌株均非社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）。
研究结论：荷兰阿姆斯特丹男男性行为者群体中的社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）感染较为罕见。金黄色葡萄球菌的生殖器定植与高危性行为无显著关联。