title: Peste des petits ruminants (PPR) in Ethiopia: analysis of a national serological survey.
abstract: BACKGROUND
  Peste des petits ruminants (PPR) is a contagious viral disease of small ruminants in Africa and Asia. In 1999, probably the largest survey on PPR ever conducted in Africa was initiated in Ethiopia where 13 651 serum samples from 7 out of the 11 regions were collected and analyzed by competitive enzyme-linked immunosorbent assay (cELISA). The objective of this paper is to present the results of this survey and discuss their practical implications for PPR-endemic regions.
  
  
  METHODS
  We explored the spatial distribution of PPR in Ethiopia and we investigated risk factors for positive serological status. Intracluster correlation coefficients (rho), were calculated for 43 wereda (administrative units).
  
  
  RESULTS
  Seroprevalence was very heterogeneous across regions and even more across wereda, with prevalence estimates ranging from 0% to 52.5%. Two groups of weredas could be distinguished on the basis of the estimated rho: a group with very low rho (rho < 0.12) and a group with very high rho (rho > 0.37).
  
  
  CONCLUSIONS
  The results indicate that PPRV circulation has been very heterogeneous, the values for the rho may reflect the endemic or epidemic presence of the virus or the various degrees of mixing of animals in the different areas and production systems. Age appears as a risk factor for seropositive status, the linear effect seeming to confirm in the field that PPRV is highly immunogenic. Our estimates of intracluster correlation may prove useful in the design of serosurveys in other countries where PPR is of importance.
authors.affiliation: Epidemiology Division, Department of Veterinary Clinical Sciences, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts. AL9 7TA, UK. awaret@rvc.ac.uk
authors.forename: Agnès
authors.initials: A
authors.lastname: Waret-Szkuta
authors.forename: François
authors.initials: F
authors.lastname: Roger
authors.forename: David
authors.initials: D
authors.lastname: Chavernac
authors.forename: Laikemariam
authors.initials: L
authors.lastname: Yigezu
authors.forename: Geneviève
authors.initials: G
authors.lastname: Libeau
authors.forename: Dirk U
authors.initials: DU
authors.lastname: Pfeiffer
authors.forename: Javier
authors.initials: J
authors.lastname: Guitián
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D005002:Ethiopia / Q000453:epidemiology; D005843:Geography; D015511:Goat Diseases / Q000453:epidemiology*; D006041:Goats; D029021:Peste-des-Petits-Ruminants / Q000453:epidemiology*; D018107:Peste-des-petits-ruminants virus / Q000276:immunology*; D015995:Prevalence; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology*
chemical_list: D000914:Antibodies, Viral
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