AsianScientist (Mar. 28, 2012) – New research funded by the World Health Organization (WHO) estimates that 20.1 million individuals were infected with hepatitis E virus (HEV) genotypes 1 and 2 across nine world regions in 2005.
According to findings available in the April issue of the journal Hepatology, there were 3.4 million symptomatic cases, 70,000 deaths, and 3,000 stillbirths from HEV that year in countries throughout Asia and Africa.
Unlike hepatitis virus B and C strains that lead to chronic disease states, HEV causes acute illness.
Previous studies show HEV genotypes 1 and 2 specifically infect humans, and are associated with large outbreaks in developing countries where sanitation conditions are poor. There is evidence that HEV increases mortality risk among pregnant women.
“Our study represents the first attempt to estimate the annual global impact of hepatitis E,” said lead author Dr. David Rein of the social science research organization NORC at the University of Chicago.
Estimates were created by modeling the disease burden of HEV genotypes 1 and 2 in the 9 regions, representing 71 percent of the world’s population. Based on published evidence the team – a collaboration between researchers from NORC, WHO, and RTI International – also estimated annual incidence of infection to determine symptomatic, asymptomatic, and mortality cases.
Of the more than 20 million people infected with HEV, 61 percent of the cases occurred in East and South Asia, two regions which also accounted for 65 percent of deaths from HEV.
The average age of infection was 17 years with the lowest age of infection in North Africa (8 years) and highest in East Asia (21 years).
The authors caution there are limitations to the study which only estimated incidence of HEV genotypes 1 and 2, leaving out genotype 3 that prevalently occurs in Europe and the U.S., and genotype 4.
“Future HEV estimates should include genotypes 3 and 4 to provide a complete picture of the global burden of HEV,” Rein said.
In January this year, China approved the world’s first hepatitis E virus (HEV) vaccine, said the Chinese Ministry of Science and Technology. The HEV 239 vaccine, sold under the trade name Hecolin™, was developed by a team of researchers from Xiamen University and Xiamen Innovax Biotech Co. Ltd. in China’s Fujian province.
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