Geographic origin trends among HIV+ mothers and children in Canada and impact on vertical HIV transmission rates

Background: Migration contributes significantly to new HIV cases in Canada. This study describes geographic origin trends among HIV+ mothers and perinatally infected children and the impact of geographic origin on vertical HIV transmission (VT) rates among HIV+ mother-infant pairs (MIP) in Canada from 1990-2013.
Methods: The Canadian Perinatal HIV Surveillance Program collects data at 22 centres. The primary focus is on MIP with an infant born in Canada and identified prior to/within 3 months of birth; MIP with Canadian-born infants identified after 3 months and HIV+ children born abroad are also tracked. Data reviewed for this study included: maternal country of origin, clinical characteristics, antiretroviral usage and infant outcome. Logistic regression determined VT rate differences for foreign-born (FBM) versus Canadian-born mothers (CBM).
Results: Among 3877 MIP, 2089 (53.9%) mothers were FBM. Of 1481 (70.9%) African mothers, 30.7%, 20.1%, 17.7%, and 16.7% came from East, Central, Horn, and West Africa, respectively. CBM accounted for 66.7% (971/1456) in Western/Central Canada, whereas FBM predominated in Ontario (945/1357, 69.6%; greatest proportion East African, 25.0%) and Quebec (713/1020, 69.9%; greatest proportion Caribbean, 36.2%). The largest numbers of FBM originated from Haiti (12.5%), Ethiopia (8.7%), Congo (7.0%), Zimbabwe (5.4%), and Nigeria (4.6%). In the pre-cART era (1990-1996), Haiti contributed 29.9% (90/301) of FBM, decreasing to 13.0% (119/918) in 1997-2007, and 6.6% (52/782) in 2008-2013. Since 2008, Ethiopia (80/782, 10.2%), Congo (64/782, 8.2%), and Nigeria (62/782, 7.9%) predominated.
VT rate among Canadian-born children from 1990-2013 was 3.8% (3.0% among FBM) and 1.2% from 2008-2013 (0.7% among FBM). African mothers had lower risk of VT (1990-2013: OR = 0.45, 95%CI 0.29-0.71; 2008-2013: OR 0.35, 95%CI 0.12-1.08) compared to CBM; no differences were seen for other regions.
Of 353 HIV+ children (born in Canada or abroad) with FBM, the greatest numbers came from Haiti (48, 13.6%), Ethiopia (33, 9.3%), Burundi (30, 8.5%), and Congo (15, 4.2%).
Conclusions: Geographic origins of HIV+ FBM in Canada have changed over time, shifting from predominantly Haitian in the pre-cART era to predominantly African more recently. African mothers have lower VT rates than CBM. Understanding country-specific cultural and obstetrical/pediatric health issues is imperative to providing optimal care.

J. Brophy1,2, T. Lee3, L. Sauve4,5, A. Bitnun6,7, J. Singer3, F. Kakkar8,9, N. Lapointe8,9, A. Alimenti4,5, D. Money4,10,11, W. Vaudry12,13, L. Samson1,2, for the Canadian Pediatric and Perinatal AIDS Research Group
1Children's Hospital of Eastern Ontario, Ottawa, Canada, 2University of Ottawa, Department of Pediatrics, Ottawa, Canada, 3CIHR - Canadian HIV Trials Network, Vancouver, Canada, 4BC Women's Hospital and Health Centre, Vancouver, Canada, 5University of British Columbia, Department of Pediatrics, Vancouver, Canada, 6The Hospital for Sick Children, Toronto, Canada, 7University of Toronto, Department of Pediatrics, Toronto, Canada, 8CHU Ste-Justine, Montréal, Canada, 9Université de Montréal, Department of Pediatrics, Montréal, Canada, 10University of British Columbia, Department of Obstetrics, Vancouver, Canada, 11Women's Health Research Institute, Vancouver, Canada, 12Stollery Children's Hospital, Edmonton, Canada, 13University of Alberta, Department of Pediatrics, Edmonton, Canada