Test uptake and case detection of syphilis, HIV, and hepatitis C among women undergoing prenatal screening in British Columbia, 2007 to 2011.

OBJECTIVE

Test uptake and case detection trends for rubella, syphilis, HIV, and hepatitis C (HCV) were compared among the 2007 to 2011 cohort of women undergoing prenatal testing in British Columbia. Analysis involved linkage of provincially centralized laboratory and surveillance data to assess prenatal test uptake and rates of newly diagnosed versus prevalent infections.

METHODS

We included prenatal specimens submitted from BC women aged 16 to 45 years in 2007 to 2011. Laboratory records were linked to provincial surveillance systems to identify confirmed maternal syphilis and HIV cases. Previous positive status was determined for HIV and HCV if a prior confirmed case was identified from laboratory records. We determined rates of HIV and HCV newly identified at prenatal screening (new diagnoses per 100 000 per year). Prevalence for HIV and HCV was the sum of all new and prior diagnoses (prevalence per 100 000 per year).

RESULTS

Of 233 203 women, 96.9% were screened for rubella, 93.3% for syphilis, 93.8% for HIV, and 21.5% for HCV. From 2007 to 2011, the overall rates of new diagnoses were 15.4, 5.1, and 82.8 cases per 100 000 per year for syphilis, HIV, and HCV, respectively. The overall prevalence was 45.9 and 551.5 cases per 100 000 per year for HIV and HCV, respectively (0.05% and 0.6%). From 2007 to 2011, new diagnoses of HCV decreased 40% from 106.0 to 62.1 cases per 100 000 per year. HCV prevalence did not change and increased with maternal age.

CONCLUSION

This study links surveillance and laboratory data to provide a provincial picture of prenatal screening test uptake and case detection, with the advantage of distinguishing new from prior diagnoses. This information can help guide prenatal communicable disease screening policy.