Tracking Killers: The Burden of Disease from Hepatitis A and E

Epidemiologists and public health researchers from multiple institutions are collaborating to gather and analyze the best available data on deaths and sick days caused by over 100 diseases and injuries around the world. The culmination of their work is the Global Burden of Disease (GBD) study. RTI Senior Health Economist David Rein is leading the modeling of disease burdens for hepatitis A and E viruses in the 2010 GBD study. "This is the first time hepatitis A and E are being included," said Rein. Both viruses are transmitted by the fecal-oral route—often through contaminated drinking water or food—and attack the liver, causing inflammation and possibly jaundice or liver failure. Rein, along with Rakesh Aggerwal in India and World Health Organization (WHO) collaborators Steven Wiersma and Gretchen Stevens, reviewed the existing literature on hepatitis E and performed a meta-analysis of seroprevalence data to find a probability for various outcomes by country and age group, including infection, symptomatic disease (i.e., feeling sick from the infection), death, or stillbirth in the case of pregnant mothers infected with the virus. The team then modeled the prevalence by global region using the DisMod III tool developed by the Institute for Health Metrics and Evaluation at the University of Washington. Tracking Killers: The Burden of Disease from Hepatitis A and E A man brushes his teeth in the Ganges River in India. The Ganges River is a highly polluted river, with a fecal coliform count estimated at 140,000 per square liter, which contributes to the spread of waterborne diseases such as cholera, dysentery, and hepatitis. ©2009 Heather Fay, Courtesy of Photoshare Epidemiologists and public health researchers from multiple institutions are collaborating to gather and analyze the best available data on deaths and sick days caused by over 100 diseases and injuries around the world. The culmination of their work is the Global Burden of Disease (GBD) study. RTI Senior Health Economist David Rein is leading the modeling of disease burdens for hepatitis A and E viruses in the 2010 GBD study. "This is the first time hepatitis A and E are being included," said Rein. Both viruses are transmitted by the fecal-oral route—often through contaminated drinking water or food—and attack the liver, causing inflammation and possibly jaundice or liver failure. Rein, along with Rakesh Aggerwal in India and World Health Organization (WHO) collaborators Steven Wiersma and Gretchen Stevens, reviewed the existing literature on hepatitis E and performed a meta-analysis of seroprevalence data to find a probability for various outcomes by country and age group, including infection, symptomatic disease (i.e., feeling sick from the infection), death, or stillbirth in the case of pregnant mothers infected with the virus. The team then modeled the prevalence by global region using the DisMod III tool developed by the Institute for Health Metrics and Evaluation at the University of Washington. "The burden of disease of hepatitis E is pretty substantial in less developed countries," said Rein. "It has a 2% death rate among adults, which jumps up to 20% in pregnant women." In the case of hepatitis A, Rein built a model from a literature review conducted by Kathryn Jacobsen at George Mason University for WHO. "We found fewer children are infected with the virus, and the overall incidence is declining," said Rein. One cause is better water and sanitation infrastructure. "On the surface that's good news, but there is a catch," Rein said. Children infected with hepatitis A generally have no symptoms, whereas youth and adults are more likely to experience severe illness. "So, paradoxically, in areas where incidence has declined due to improvements in water and sanitation, the burden shifts, resulting in outbreaks among youth and adults," Rein said. "This suggests that countries experiencing the shift should consider vaccination strategies against hepatitis A." Rein and his collaborators will be publishing results from the hepatitis A and E modeling later this year. Through modeling the burden of disease for hepatitis A, RTI found that fewer children were infected in 2005 than in 1990, raising the average age of infection around the world. However, the introduction of vaccination programs in the United States starting in 1999 disrupted the natural epidemiology of the virus and led to a lower age of infection and far fewer infections overall in North America. More information: David Rein, e-mail [email protected]