Field development and validation of a salivary hepatitis E assay in Bangladesh
Summary
Hepatitis E virus (HEV) is the leading global cause of acute viral hepatitis; particularly in South
Asia where seasonal floods contaminate drinking water supplies leading to frequent hepatitis E
(HE) epidemics. Whereas case-fatality rates in the general population can vary from 0.1-3.0%,
elevated mortality (10-40%) in pregnant women infected with HEV genotype 1 has been
observed in South Asia. Current methods to confirm infection rely on enzyme
immunoassays (EIA) for detection of IgM or IgG antibodies to HEV (anti-HEV) in serum or
PCR of HEV RNA in serum or stool. Collection of blood and stool is invasive and suffers
practical constraints in children under 5 and pregnant women in resource-limited settings which
may impede the ability to make frequent follow-up measurements in epidemiologic studies. This
research will serve three purposes. First, to optimize and validate an HEV salivary EIA by
evaluating the sensitivity, specificity, and reliability of HEV EIAs in de-identified paired saliva
and finger-stick blood samples from patients at Dhaka Shishu Hospital, Dhaka, Bangladesh, an
area where HEV is endemic. Second, compare a saliva self-collection protocol with saliva
collected by trained staff. And third, to advance efforts to integrate the optimized HEV salivary
EIA into ongoing and future epidemiologic studies which would refine understanding of the time
windows of immunoconversion and progression of infectious vs subclinical HE symptoms.