RT Journal Article SR Electronic T1 Gonorrhoea and chlamydia core groups and sexual networks in Manitoba JF Sexually Transmitted Infections JO Sex Transm Infect FD BMJ Publishing Group Ltd SP i145 OP i151 DO 10.1136/sti.78.suppl_1.i145 VO 78 IS suppl 1 A1 A M Jolly A1 J L Wylie YR 2002 UL http://sti.bmj.com/content/78/suppl_1/i145.abstract AB This paper summarises the results of the R0 equation in sexually transmitted infection (STI) repeaters in Manitoba, Canada, in the early 1990s, with both concurrent and more recent descriptions of sexual networks in the same population. The research presented provides empirical network and sex partner data to refine definitions of sexual networks and core groups in phase IV epidemics. New challenges for both practice and research are also discussed.