HIV infection impairs immunity to malaria in pregnant women

"Scientists from the University of Melbourne, Australia, the United States and Malawi studying infections with malaria and HIV, have found a strong link between the two diseases, which affect millions of people around the world and are major scourges in sub-Saharan Africa.

One of their reports, appearing in the April 30 issue of the journal AIDS, shows that malaria makes HIV worse in pregnant women and may increase the risk of transmission of HIV to their babies.

A second paper will be published in the June 5 issue of the Lancet, a British medical journal. It reports for the first time that HIV impairs immunity to malaria in pregnant women. Together, the work demonstrates that interactions between malaria and HIV make women with both infections much worse off than those with either one alone, the scientists say.

Authors include Dr Stephen Rogerson and Ms Adele Mount of the University of Melbourne's Department of Medicine at the Royal Melbourne Hospital in Australia, Dr Steven Meshnick of the University of North Carolina at Chapel Hill and Dr Victor Mwapasa of the University of Malawi, one of Meshnick's former students. Rogerson was the principal investigator for the Lancet study.

"This work is important because it suggests that if we can protect women from malaria when they are pregnant, we might be able to reduce the likelihood of their transmitting HIV to their babies," Meshnick said.

"Also, if a woman has both diseases, it shows you need to control the HIV to make her less susceptible to malaria.

"In other words, the two infections go hand-in-hand," he said.

"The findings also suggest that two important programs in Africa -- to prevent malaria in pregnancy and mother-to-child transmission of HIV -- ought to be combined."

According to Rogerson, tens of millions of African women are exposed to malaria during pregnancy each year.

Often, their babies have low birth weights and face a strongly reduced chance of surviving the first year of life. Malaria is the most frequent preventable cause of complications in pregnancy in Africa.

"In Malawi, about a third of new mothers suffer from malaria, and about a third are HIV-infected," said Rogerson.

"Roughly 10 percent have both illnesses," he said.

The findings highlight an important mechanism by which HIV infection increases susceptibility to malaria in pregnant women, the authors said. It likely will have important implications for malaria vaccine development in this group and may also be relevant to malaria susceptibility in other HIV-infected groups.

The National Institutes of Health and the Wellcome Trust supported the research.

http://www.unimelb.edu.au