Screening in Pregnancy is Key to Eliminating Mother-to-Child HIV Transmission

Canada has almost eliminated mother-to-child HIV transmission, known as vertical transmission, in recent years by ensuring that all women have the opportunity to be screened for HIV in pregnancy and that women with the disease receive treatment before giving birth. In 2014, there was only one recorded transmission of the virus to babies born to women known to be living with HIV. These findings were presented at the International AIDS Society 2015 conference in Vancouver by researchers from the Canadian Perinatal HIV Surveillance Program (CPHSP), a national group that has been collecting annual surveillance data about children born to women with HIV in Canada since 1990.

"Effectively, Canada has eliminated vertical transmission," says Dr. Jason Brophy, chair of the Canadian Pediatric & Perinatal AIDS Research Group (CPARG) which runs the CPHSP. CPARG has been active for 25 years in advocating for improved prevention of vertical HIV transmission and better care of children with HIV. "The World Health Organization definition of elimination is less than 2 percent 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."

Women who receive combination antiretroviral therapy (cART) during pregnancy do not pass HIV on to their baby. Regular cART treatment is almost 100 per cent effective in preventing transmission when given for enough time to suppress the virus in the mother.

In three separate poster presentations about the surveillance program, CPHSP researchers examined the progress Canada has made in treating women with HIV, preventing the disease in infants as well as opportunities to improve care. They determined which populations are at greatest risk and how public health officials are working with those groups.

Since the 1990s, about half of women with HIV delivering babies in Canada were foreign born. Aboriginal women and women who use injection drugs were also at greater risk of having HIV in pregnancy and had consistently lower rates of treatment. Promising new findings in 2014 show that these two groups now have treatment rates comparable to 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," says Joel Singer, a professor in the School of Population and Public Health at UBC, who is presenting at IAS 2015. "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."

The researchers say this recent success stems largely from public health initiatives to ensure women in these high-risk populations are tested and receive the proper prenatal care. The researchers say the key to reaching the goal of zero transmission between mothers and infants is to engage hard-to-reach populations in healthcare and allow them to access prenatal care, HIV testing and cART treatment.

Source: University of British Columbia