Types of Gonorrhea Within Sexual Networks Over Time in Manitoba, Canada

Abstract

Background and Rationale: As the number of gonococcal infections reported in Manitoba diminishes and infections concentrate in core groups, innovative methods are required to elucidate the dynamics within these groups that facilitate the transmission of the organism. We combine methods of social network analysis and molecular biology to describe the epidemiology of Neisseria gonorrhoeae. Objective: To identify types of gonorrhea in the associated sexual networks in Manitoba over time. Methods: All isolates submitted to Cadham Provincial Laboratory in Manitoba for gonorrhea culture from October 1996 until September 1997 were collected. The isolates were typed by pulsed field gel electrophoresis (PFGE), serotype, and opatype. Information on the partners of these individuals from the provincial communicable disease control unit was entered into social network analysis programs. Results: Using the information on the partners of 29 individuals with isolates, 23 networks consisting of 81 individuals were constructed. There was agreement of pulsed field type and serotype within each network with multiple isolates. Specimen dates of cases or dates on which partners were located were obtained for 75 cases and contacts. The networks ranged in size from one to 14 individuals, spanning 5 to 307 days. Long time spans were not associated with larger network sizes (P = 0.1) nor with discordant PFGE types within the networks. This may indicate that recruitment or reporting of new sex partners does not increase proportionately over time, or it may reflect the likelihood of obtaining a positive test in named contacts, which determines whether the contact tracing process continues, or whether it terminates. Conclusions: The combination of sexual network analysis with molecular biology is valuable in understanding the genetic distribution, transmission, and antimicrobial resistance of N gonorrhoeae.