The Canadian perinatal HIV surveillance program (CPHSP): program description and trends in demographics, treatment and transmission

Background: The Canadian Perinatal HIV Surveillance Program (CPHSP) is an active surveillance program generating national data HIV+ women and their infants in Canada since 1990. We describe the CPHSP''s evolving methodology and analyze mother-infant pair (MIP) demographics, antiretroviral treatment and vertical transmission (VT) rates in Canada from 1990-2013.
Methods: MIPs are identified at 22 centers following obstetric or pediatric referral for care. Data is entered via a secure web-based Oracle database, which is managed and analysed by the CIHR-Canadian HIV Trials Network. A nationally representative steering committee provides direction and oversight. Data collected include maternal characteristics, antiretroviral therapy (ART) and infant outcome. VT rates are based on data of MIP delivered in Canada and identified within 3 months after birth; infants identified beyond 3 months of birth are tracked separately.
Results: Among 2914 MIP from the combination ART (cART) era (1997-2013), the overall VT rate was 2.1% but only .7% in MIP receiving cART and 0.1% in women receiving >4 week of cART. Of 200 identified HIV+ women giving birth in Canada in 2013, 76% acquired HIV heterosexually, 17% through injection drug use (IDU) and 2% perinatally; 53% of mothers were Black and 23% Aboriginal. The proportion untreated steadily decreased from 20.3% in 1997 to 3.0% in 2013. Aboriginal women (7%) continued to represent the largest proportion of untreated women (7%) in 2013, though this decreased from a peak of over 20% during the period 2005-2009. . A similar improvement was seen among IDU, with only 3% untreated in 2013. In 2013, seven (3.5%) women had no antenatal cART or suboptimal treatment, the lowest annual number and percentage in the cART era, resulting in two children becoming infected.
Conclusions: The CPHSP allows for comprehensive identification of perinatal HIV exposure and outcome trends in Canada. Ongoing challenges include ensuring all MIPS are captured given Canada''s geographically and demographically diverse population and low HIV prevalence. Despite continued improvement in treatment access for pregnant HIV+ women, VT continues to occur with Aboriginal women being at greater risk of inadequate treatment and VT.

J. Singer1,2, A. Bitnun3, T. Lee4, L. Samson5, J. Brophy5, D. Money6, A. Alimenti6, W. Vaudry7, F. Kakkar8, N. Lapointe8, L. Sauve6, Canadian Pediatric & Perinatal AIDS Research Group
1University of British Columbia, School of Population and Public Health, Vancouver, Canada, 2CIHR Canadian HIV Trials Network, Vancouver, Canada, 3Hospital for Sick Children, University of Toronto, Toronto, Canada, 4CIHR Canadian HIV Clinical Trials Network, Vancouver, Canada, 5Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Canada, 6BC Women's Hospital and Health Centre, University of British Columbia, Vancouver, Canada, 7Stollery Children's Hospital, University of Alberta, Edmonton, Canada, 8Hopital Ste-Justine, University of Montreal, Montreal, Canada