Prevention of vertical HIV transmission has evolved significantly in Canada over the last two decades. The aim of this analysis is to describe the surveillance programme used, rate of vertical HIV transmission and changing epidemiology of HIV-affected pregnancies in Canada.
National perinatal HIV surveillance programme.
From 1990, annual retrospective data was collected on demographic and clinical characteristics of HIV-infected mothers and their infants referred to 22 participating sites across Canada either before/during pregnancy or within 3 months after delivery. Factors impacting HIV transmission and demographic features were explored.
Two thousand, six hundred and ninety-two mother–infant pairs were identified. The overall rate of vertical HIV transmission was 5.2%, declining to 2.9% since 1997. The rate of transmission for mothers who received HAART was 1%, and 0.4% if more than 4 weeks of HAART was given. Forty percent of women delivered by caesarean section, with no difference in transmission rate compared with vaginal delivery for women treated with HAART (1.4 vs. 0.6%, P = 0.129) but significant risk reduction for those who did not receive HAART (3.8 vs. 10.3%, P = 0.016). Black women were the largest group; proportions of black and aboriginal women increased significantly over time (P < 0.001 for both). Heterosexual contact was the most common risk category for maternal infection (65%), followed by injection drug use (IDU) (25%).
Vertical HIV transmission in Canada has decreased dramatically for women treated with HAART therapy. All pregnant women should be evaluated for HIV infection and programmes expanded to reach vulnerable populations including aboriginal, immigrant and IDU women.
aDepartment of Pediatrics
bSchool of Population and Public Health, University of British Columbia, Vancouver, British Columbia
cDepartment of Pediatrics, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa
dDepartment of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario
eDepartment of Obstetrics and Gynecology, Women's Health Research Institute, British Columbia Women's Hospital and Health Centre, University of British Columbia
fCIHR Canadian HIV Trials Network, Vancouver, British Columbia
gDepartment of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada.
Correspondence to Dr Ariane M. Alimenti, Oak Tree Clinic, 4500 Oak Street – B4 West, Children's and Women's Health Centre of British Columbia, Vancouver, BC V6H 3N1, Canada. Tel: +1 604 875 2212; fax: +1 604 875 3063; e-mail: firstname.lastname@example.org
Received 2 September, 2011
Revised 7 December, 2011
Accepted 20 December, 2011