That's a half million newborn worldwide every year facing chronic illness and premature death on their first day out of the safety of the womb.

"The question has always been how does the virus get from the mothers to the babies?" said principal investigator Dr. Steven Meshnick, professor of epidemiology at the University of North Carolina at Chapel Hill School of Public Health. "We have known very little about it."

Now, Meshnick and colleagues think they have discovered a major reason why that occurs. A new study they conducted with 149 pregnant HIV-infected women in the African nation of Malawi showed that tiny amounts of virus-laden blood leak from women's placentas to babies during labor. All of the subjects and their babies had been given single-dose anti-retroviral drugs to minimize HIV transmission.

"This work shows strongly for the first time that what we call placental microtransfusions during birth are responsible for a large part of the transmission of HIV from mother to baby," the scientist said. "To our knowledge, there have never been any data like this before."

A report on the research appears today (Nov. 21) in the latest issue of the journal PloS Medicine. PloS is an acronym for Public Library of Science.

Besides Meshnick, UNC epidemiology authors are Dr. Jesse Kwiek, a postdoctoral fellow; graduate student Alisa Alker; and assistant professor Dr. William Miller, also assistant professor of medicine at the UNC School of Medicine. Other authors are Drs. Victor Mwapasa, Eyob Tadesse and Malcolm Molyneux of the University of Malawi, Dr. Danny A. Milner, a Harvard University pathologist, and Dr. Stephen Rogerson, associa
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Contact: David Williamson
rdtokids@email.unc.edu
919-962-8596
University of North Carolina at Chapel Hill
21-Nov-2005