title: Hepatitis E antibody seroconversion without disease in highly endemic rural Egyptian communities.
abstract: Hepatitis E virus (HEV) is enterically transmitted and causes self-limiting acute viral hepatitis (AVH) primarily in less developed countries. A prospective cohort study to assess incidence of, and risk factors for, seroconversion to HEV (anti-HEV) was conducted in two Egyptian villages with a 67.7% anti-HEV prevalence. Nine hundred and nineteen villagers who were initially anti-HEV-negative were followed for 10.7 months. Thirty-four (3.7%) had strong anti-HEV serologic responses at follow-up giving an estimated anti-HEV incidence of 41.6/1,000 person-years. No significant associations were found between anti-HEV seroincidence and demographic and socioeconomic factors, source of water, household plumbing or sanitation, hand and vegetable washing, ownership of animals, jaundice and many other variables. None of the seroconverting subjects gave a history compatible with AVH during the interval. We hypothesize that both zoonotic and anthroponotic transmission of avirulent (possibly genotype-3) HEV is occurring extensively in these rural villages. An alternative explanation for the lack of morbidity among anti-HEV incident cases could be initial asymptomatic infections occur during early childhood with subsequent antibody titer boosting without illness upon re-exposure to the virus.
authors.affiliation: International Health Division, Department of Epidemiology and Preventive Medicine, School of Medicine, University of Maryland, 660 W. Redwood Street, Baltimore, MD 20201, USA.
authors.forename: Sonia K
authors.initials: SK
authors.lastname: Stoszek
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Engle
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdel-Hamid
authors.forename: Nabiel
authors.initials: N
authors.lastname: Mikhail
authors.forename: Fatma
authors.initials: F
authors.lastname: Abdel-Aziz
authors.forename: Ahmed
authors.initials: A
authors.lastname: Medhat
authors.forename: Alan D
authors.initials: AD
authors.lastname: Fix
authors.forename: Suzanne U
authors.initials: SU
authors.lastname: Emerson
authors.forename: Robert H
authors.initials: RH
authors.lastname: Purcell
authors.forename: G Thomas
authors.initials: GT
authors.lastname: Strickland
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D015331:Cohort Studies; D004534:Egypt / Q000453:epidemiology; D019353:Endemic Diseases; D005260:Female; D006508:Hepatitis Antibodies / Q000097:blood*; D016752:Hepatitis E virus / Q000276:immunology*; D006525:Hepatitis, Viral, Human / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012423:Rural Health; D016036:Seroepidemiologic Studies
chemical_list: D006508:Hepatitis Antibodies