Program Eliminates Vertical HIV Transmission

The results of three studies presented at the International AIDS Society 2015 conference in Vancouver indicate that Canada has virtually eliminated mother-to-child, or vertical, HIV transmission in recent years. The good news is the result of a nation-wide program that ensures that all women have the chance to be screened for HIV during pregnancy and that those found to have HIV receive treatment before giving birth.

In 2014, the program—named the Canadian Perinatal HIV Surveillance Program (CPHSP)—led to only one recorded transmission of the virus to a baby born to a woman known to be living with HIV. Through CPHSP, a national group of researchers has been collecting annual surveillance data on children born to women with HIV in Canada since 1990.

“Effectively, Canada has eliminated vertical transmission,” said Jason Brophy, MD, chair of the Canadian Pediatric & Perinatal AIDS Research Group (CPARG), which runs the CPHSP. For 25 years, CPARG has advocated for improved prevention of vertical HIV transmission along with better care for children with HIV.

“The World Health Organization definition of elimination is less than two per cent transmission and that's where we are right now. But of course, we’d like to get to zero and I know that we can,” said Brophy, who is also a pediatric infectious diseases physician and clinician-investigator at the Children’s Hospital of Eastern Ontario, and an Assistant Professor of Pediatrics at the University of Ottawa.

With the knowledge that regular combination antiretrovival therapy during pregnancy is nearly 100% effective in preventing vertical transmission when given early enough to suppress the virus in the mother, CPHSP study investigators working on all three trials examined the progress made in Canada in recent years in treating women with HIV. The research teams also assessed progress in preventing the disease in infants and how care could be improved in this area. Populations that were at greatest risk for vertical transmission and how public health officials are working with these populations were also determined.

According to the research, nearly 50% of women with HIV who delivered babies in Canada since the 1990s were foreign born. Aboriginal women and injection drug users were at greater risk of having HIV during pregnancy yet had consistently lower rates of treatment, when compared with other women. But in 2014, these two sub-populations had treatment rates that were comparable to those of other women.

“The database has allowed us to assess the national burden of HIV infection through vertical transmission throughout the HIV/AIDS epidemic and to identify the populations at greatest risk,” said Joel Singer, PhD, professor in the School of Population and Public Health at the University of British Columbia. “The happy conclusion, at this point, is that vertical transmission in Canada is rare, and groups which were at excess risk are no longer so.”

According to the researchers presenting all three studies, paramount to reaching the goal of zero vertical HIV transmission is the engagement in healthcare of hard-to-reach populations and their access to prenatal care, HIV testing, and combination antiretroviral therapy.