Epidemiology of the reemergence of gonorrhea in Sweden

Background: After many years of decline, the incidence of gonorrhea in Sweden reached an all-time low of 2.4 cases per 100,000 inhabitants in 1996; however, the incidence has been increasing since 1997. Goal: To describe the reemergence of gonorrhea in Sweden using clinical epidemiologic data and microbiologic characterization of isolated strains of Neisseria gonorrhoeae. Study Design: N gonorrhoeae strains isolated in Sweden from February 1998 to January 1999 were serotyped and an epidemiologic data questionnaire was sent to each clinician reporting a case of gonorrhea. Results: Epidemiologic and microbiologic data were obtained for 357 cases (91% of all cases diagnosed during the period). Domestic cases had significantly increased since 1997. Serovar IB-3 was the most common isolate in domestic cases of heterosexually exposed teenagers, and serovar IB-2 was the most frequent isolate in domestic cases of homosexually exposed men. Of the imported cases, 47% were exposed in Asia and 6.5% were exposed in Eastern Europe. Conclusion: The increase of gonorrhea in Sweden is due to an increase of domestic cases. Heterosexual teenagers and homosexual men were identified as core groups infected by different serovars of N gonorrhoeae.