Syphilis in Denmark-Outbreak among MSM in Copenhagen, 2003-2004.

Denmark is currently experiencing an outbreak of syphilis that began in 2003 and has continued in 2004. Data from the national surveillance system show that most cases are in men who have sex with men (MSM), and that a large proportion of these patients are also HIV positive. The proportion of known HIV positive cases in MSM notified with syphilis during the outbreak has, however, not been significantly different from previous years. The majority of cases were reported from Copenhagen municipality, and 70% of the cases were acquired domestically. The outbreak does not seem to be affecting the age group under 20 years. We speculate that most of the MSM found with both syphilis and HIV were already HIV positive when they acquired syphilis infection.