Researchers are reporting a link between vitamin D and zinc deficiencies and immune dysfunction and hepatitis E infection risk in pregnant women. The research, by scientists at the Johns Hopkins Bloomberg School of Public Health, was published in American Society of Tropical Medicine and Hygiene and titled “The Association of Cytokines and Micronutrients with Hepatitis E Virus Infection During Pregnancy and the Postpartum Period in Rural Bangladesh.”
The hepatitis E (HEV) virus, while rare in the United States and most developed countries, is common in developing countries where clean water supplies are inadequate, since HEV is mainly transmitted through contaminated water. According to the World Health Organization, 20 million infections and 3.3 million acute cases occur worldwide each year. HEV infection is particularly devastating for pregnant women, whose mortality rate is 30% — 20% in the third trimester — compared to 0.5%–2% in the overall population.
In Southeast Asia, researchers estimates that hepatitis E is responsible for some 10,500 maternal deaths every year.
The team collected blood samples from 1,100 women in northern Bangladesh during the first trimester of pregnancy, third trimester, and three months after giving birth. Antibodies against HEV, several pro- and anti-inflammatory cytokines, and 12 vitamins and minerals were measured in all participants. During the study, 40 women became infected with the virus, and the control group was defined as a subset of women, matched by age and place of residence, who were virus-free.
Results showed that women who developed HEV infections had higher levels of pro- and anti-inflammatory cytokines when compared to controls. Importantly, this was also observed prior to infection. In the first trimester, these women had lower levels of circulating zinc, increased prevalence of vitamin D deficiency (95% compared to 82.5% in the controls), and anemia.
“For decades, we’ve been asking why pregnant women who get hepatitis E die at an alarming rate. This research suggests that pre-existing differences could be the key we’ve been seeking,” study leader Alain Labrique, PhD, an associate professor in the Bloomberg School’s Department of International Health, said in a press release. “Even though women are exposed to similar environmental risk factors, the differences in pre-existing characteristics seem to put some women at a much higher risk of getting infected, sick and dying. These findings could pave the road for stepped-up nutritional monitoring of pregnant women in this part of the world and lead to recommendations for nutritional supplements.”
Dr. Labrique added, “Most of the current knowledge about how hepatitis E affects pregnant women comes from studies looking at women who are already infected. This population-based study was able to look at the health status of pregnant women before they became infected. If we can better understand what predisposes pregnant women to infection, we could also develop better programs that prevent infection from ever occurring.”