Increases in @entity645 incidence among @entity1 who have sex with @entity1 undergoing repeat diagnostic XXXX testing in Ontario, Canada.

@entity1 @entity281 @entity645 @entity2101
OBJECTIVE: To estimate @entity645 incidence density for different exposure categories among @entity1 undergoing repeat testing in Ontario, Canada. METHODS: @entity1 using voluntary, diagnostic @entity645 testing at least twice were identified by computerized and manual record linkage. In the 1992-2000 period, 980 seroconverters and 340 994 repeat negative testers contributed 936 145 @entity1 years (PY) of observation. @entity2101 ( @entity2101 ) was calculated according to Kitayaporn et al. Poisson regression was used to evaluate differences in incidence. RESULTS: Among @entity1 who have sex with @entity1 (MSM), @entity2101 declined between 1992-1996, from 1.23 per 100 PY in 1992 to 0.79 per 100 PY in 1996 [relative risk (RR), 0.86 per year; 95% confidence interval (CI), 0.77-0.96]. Subsequently, @entity2101 increased to 1.39 per 100 PY in 1999 (RR, 1.18 per year; 95% CI, 1.05-1.34). In 2000, @entity2101 was 1.16 per 100 PY but this decrease was not statistically significantly different from 1999. MSM in their twenties had the highest @entity2101 in 1992-1996, but in 1996-2000 MSM in their thirties had the highest risk of @entity281 . Among injecting drug users (IDU), @entity2101 decreased from 0.64 per 100 PY in 1992 to 0.14 per 100 PY in 2000 (RR, 0.87 per year; 95% CI, 0.80-0.94). Among heterosexuals, annual incidence remained constant at about 0.03 per 100 PY in 1992-2000. CONCLUSIONS: Increases in @entity2101 were identified among MSM from 1996 to 1999. These findings are consistent with other research. Continued vigilance and improved surveillance are needed to better understand and control the epidemic.
