title: Serologic evidence for hepatitis E virus infection among patients with undifferentiated acute febrile illness in Kibera, Kenya.
abstract: BACKGROUND
  Hepatitis E (HEV) is an emerging cause of viral hepatitis mainly transmitted through the fecal-oral route. Residents of the Kibera slum of Nairobi, Kenya are at risk for fecal-orally transmitted infections.
  
  
  OBJECTIVE
  To quantify the incidence and prevalence of HEV infection among acute febrile illness (AFI) cases using a population-based infectious disease surveillance network.
  
  
  METHODS
  Cross-sectional serum samples from AFI case-patients between 2009 and 2012 were matched to the age and gender distribution of the Kibera population and tested by IgM and IgG enzyme immunoassays (EIA) and nucleic acid testing (NAT). Serum from healthy residents was also tested by EIA.
  
  
  RESULTS
  Of the 482 AFI serum samples tested, 124 (25.7%) and 182 (37.8%) were IgM and IgG reactive, respectively. On multivariate analysis, IgM reactivity was associated with HIV (RR 1.66, 95%CI 1.07, 2.60; p=0.024) while IgG reactivity was associated with increasing age (p<0.001) and HIV (RR 1.93, 95%CI 1.52, 2.46; p<0.001). AFI case-patients were more likely to be IgM (p=0.002) and IgG (p<0.001) reactive compared to healthy residents. The seroincidence by HEV-specific IgM was 84.0 per 1000 person years, however, all 482 samples were negative by NAT.
  
  
  CONCLUSIONS
  Serologic evidence for HEV in Kibera suggests a high burden of infection, but NAT did not confirm HEV viremia. Additional testing is needed to determine whether EIAs are susceptible to false positivity in undifferentiated AFI populations before their widespread use.
authors.affiliation: Department of Medicine, University of Washington, Seattle, WA, USA. Electronic address: furukn1@uw.edu.
authors.forename: N W
authors.initials: NW
authors.lastname: Furukawa
authors.affiliation: Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: E H
authors.initials: EH
authors.lastname: Teshale
authors.affiliation: Center for Global Health, Division of Global Health Protection, Centers for Disease Control and Prevention, Nairobi, Kenya.
authors.forename: L
authors.initials: L
authors.lastname: Cosmas
authors.affiliation: Kenya Medical Research Institute, Center for Global Health Research, Nairobi, Kenya.
authors.forename: M
authors.initials: M
authors.lastname: Ochieng
authors.affiliation: Kenya Medical Research Institute, Center for Global Health Research, Nairobi, Kenya.
authors.forename: S
authors.initials: S
authors.lastname: Gikunju
authors.affiliation: Center for Global Health, Division of Global Health Protection, Centers for Disease Control and Prevention, Nairobi, Kenya.
authors.forename: B S
authors.initials: BS
authors.lastname: Fields
authors.affiliation: Center for Global Health, Division of Global Health Protection, Centers for Disease Control and Prevention, Nairobi, Kenya.
authors.forename: J M
authors.initials: JM
authors.lastname: Montgomery
mesh_terms: D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D003430:Cross-Sectional Studies; D005334:Fever / Q000453:epidemiology*; D016751:Hepatitis E / Q000453:epidemiology* / Q000276:immunology* / Q000821:virology; D016752:Hepatitis E virus / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D007630:Kenya / Q000453:epidemiology; D012698:Serologic Tests
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M
keywords: Acute febrile illness; Enzyme immunoassay; Hepatitis E; Kenya; Kibera; Nucleic acid testing