Community associated MRSA prevalence en risicfactors among men who have sex with men

Methicilline Resistent Staphylococcus Aureus (MRSA) is a hospital bacteria
which can cause large therapeutical problems. Since 1986 community aqcuired
MRSA (CA-MRSA) has been reported in the healthy general population outside
hospitals. In the Netherlands, CA-MRSA is found among pig farmers and in the
United States among men who have sex with men (MSM, homo and bisexual men).
CA-MRSA can cause skin and soft tissue infections like abcesses, impetigo and
folliculitis. Beginning 2008 an even more resistent and virulent CA-MRSA strain
(USA 300) has been identified among MSMA, first in San Franscisco and Boston
and more recently in Germany. Also at the STI clinic of the Health Service
Amsterdam the first case of USA 300 CA-MRSA has been identified.

In this study we want to study:
1) what is the prevalence of CA-MRSA asymptomatic carriership among MSM
policlinic visitors?
2) What are risk factors for CA-MRSA carriership and/or infections among MSM?
3) Is CA-MRSA among MSM transmitted through sexual networks?
4) What is the prevalence of symptomatic CA-MRSA induced skin infections among
MSM policlinic visitors?

At the STI outpatient clinic, 125 MSM will be screened for CA-MRSA carriership
via swabs collected from the pharinx, nasal cavity, penis and perianal region.
Moreover, at the STI and dermatology outpatient clinic, from 75 MSM with
symptomatic skin infections targeted swabs will be collected. From all
participants a questionnaire focussed on risk factors will be recorded.
If MRSA is found, molecular diagnostic analysis (MLVA, PCR and DNA sequencing)
will be perfomed. Phylogenetic analysis with Bayesian Monte Carlo Markov chain
(MCMC) studies will be used to reveal possible sexual networks and riskfactors.

Swab collection is harmless and causes no discomfort. In case CA-MRSA is
detected, this will have consequences for hospital visits. Participants will be
seen and treated separate from outher visiting patients.