title: A large outbreak of hepatitis E among a displaced population in Darfur, Sudan, 2004: the role of water treatment methods.
abstract: BACKGROUND
  The conflict in Darfur, Sudan, was responsible for the displacement of 1.8 million civilians. We investigated a large outbreak of hepatitis E virus (HEV) infection in Mornay camp (78,800 inhabitants) in western Darfur.
  
  
  METHODS
  To describe the outbreak, we used clinical and demographic information from cases recorded at the camp between 26 July and 31 December 2004. We conducted a case-cohort study and a retrospective cohort study to identify risk factors for clinical and asymptomatic hepatitis E, respectively. We collected stool and serum samples from animals and performed a bacteriological analysis of water samples. Human samples were tested for immunoglobulin G and immunoglobulin M antibody to HEV (for serum samples) and for amplification of the HEV genome (for serum and stool samples).
  
  
  RESULTS
  In 6 months, 2621 hepatitis E cases were recorded (attack rate, 3.3%), with a case-fatality rate of 1.7% (45 deaths, 19 of which involved were pregnant women). Risk factors for clinical HEV infection included age of 15-45 years (odds ratio, 2.13; 95% confidence interval, 1.02-4.46) and drinking chlorinated surface water (odds ratio, 2.49; 95% confidence interval, 1.22-5.08). Both factors were also suggestive of increased risk for asymptomatic HEV infection, although this was not found to be statistically significant. HEV RNA was positively identified in serum samples obtained from 2 donkeys. No bacteria were identified from any sample of chlorinated water tested.
  
  
  CONCLUSIONS
  Current recommendations to ensure a safe water supply may have been insufficient to inactivate HEV and control this epidemic. This research highlights the need to evaluate current water treatment methods and to identify alternative solutions adapted to complex emergencies.
authors.affiliation: Epicentre, Paris, France. jguthmann@epicentre.msf.org
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Guthmann
authors.forename: Hilde
authors.initials: H
authors.lastname: Klovstad
authors.forename: Delia
authors.initials: D
authors.lastname: Boccia
authors.forename: Nuha
authors.initials: N
authors.lastname: Hamid
authors.forename: Loretxu
authors.initials: L
authors.lastname: Pinoges
authors.forename: Jacques-Yves
authors.initials: JY
authors.lastname: Nizou
authors.forename: Mercedes
authors.initials: M
authors.lastname: Tatay
authors.forename: Francisco
authors.initials: F
authors.lastname: Diaz
authors.forename: Alain
authors.initials: A
authors.lastname: Moren
authors.forename: Rebecca Freeman
authors.initials: RF
authors.lastname: Grais
authors.forename: Iza
authors.initials: I
authors.lastname: Ciglenecki
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Nicand
authors.forename: Philippe Jean
authors.initials: PJ
authors.lastname: Guerin
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D016751:Hepatitis E / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012367:RNA, Viral; D012307:Risk Factors; D013397:Sudan / Q000453:epidemiology; D018508:Water Purification / Q000379:methods*
chemical_list: D012367:RNA, Viral