During the first year of life, breastfeeding could protect infants exposed to HIV at birth from other infectious diseases, according to a study from the University of Washington School of Public Health, the University of Nairobi and the Kenya Medical Research Institute.

The study, published in the August 2016 edition of the Journal of Human Lactation, found that breastfeeding decreased a child’s risk of being hospitalized due to infectious disease by 61 percent.

About 1.5 million women infected with HIV give birth in developing countries every year. Although prevention of mother-to-child transmission of HIV is becoming more successful, in Kenya 15 percent of infants born to mothers with HIV will become infected.

"Infants in resource-limited settings who are HIV-exposed—that is, they are born to HIV-infected women but are uninfected at birth—are a vulnerable population with unique needs,” says lead author Kristjana Ásbjörnsdóttir, a research scientist in the School’s Department of Global Health and alumna of the Department of Epidemiology. “They’re at risk of acquiring HIV through breastfeeding and those who remain HIV-uninfected are at higher risk of other infectious morbidity and mortality compared to infants who are not HIV-exposed.”

Infant feeding recommendations for HIV-infected women “have attempted to balance the benefits of breastfeeding against the risks for years,” Ásbjörnsdóttir adds.

Using data from a previous cohort of HIV-infected mothers and their infants, the researchers identified 388 babies in Nairobi, Kenya, who were confirmed to be HIV-uninfected at birth. The babies were examined within 48 hours of delivery, at two weeks old, and then monthly until they were a year old.

Among the babies studied, 113 hospitalizations were reported, and nearly 80 percent were caused by one or more infectious diseases—primarily pneumonia, gastroenteritis and sepsis.

"Current guidelines for HIV-infected women recommend lifelong antiretroviral treatment started during pregnancy or breastfeeding. This allows the World Health Organization to recommend breastfeeding to HIV-infected women, because antiretroviral treatment prevents HIV transmission during breastfeeding,” Ásbjörnsdóttir says. “Our study demonstrates that breastfeeding is associated with a significant reduction in serious infectious morbidity in HIV-exposed infants and suggests that efforts to support breastfeeding will prevent serious morbidity and hospitalizations in HIV exposed uninfected infants."

Ásbjörnsdóttir co-authored the study with SPH colleagues Jennifer Slyker, assistant professor of global health and adjunct assistant professor of epidemiology, and Grace John-Stewart, professor of epidemiology and global health, and with long-term UW collaborators at the University of Nairobi and KEMRI.