The evolving epidemiology of chlamydial and gonococcal infections in response to control programs in Winnipeg, Canada.

OBJECTIVES: The purpose of this study was to describe and compare the transmission dynamics of chlamydia and gonorrhea in Winnipeg, Manitoba, Canada, and to assess implications for control programs. METHODS: Chlamydia and gonorrhea surveillance case reports (1988 through 1995) and contact-tracing reports (1991 through 1995) were examined. RESULTS: High incidence rates of both chlamydia and gonorrhea clustered in geographic core areas characterized by low socioeconomic status. A decline in the number of reported cases of chlamydia (61%) and gonorrhea (64%) occurred between 1988 and 1995. For chlamydia, the decline was most prominent in non-core area cases, while for gonorrhea it was similar in core and non-core areas. CONCLUSIONS: Chlamydia and gonorrhea appear to be evolving through different epidemic phases, with chlamydia transmission, in response to a newly introduced control program, becoming more core dependent and gonorrhea transmission becoming more sporadic in the face of a sustained control effor...