title: Prevalence study of yaws in the Democratic Republic of Congo using the lot quality assurance sampling method.
abstract: BACKGROUND
  Until the 1970s the prevalence of non-venereal trepanomatosis, including yaws, was greatly reduced after worldwide mass treatment. In 2005, cases were again reported in the Democratic Republic of the Congo. We carried out a survey to estimate the village-level prevalence of yaws in the region of Equator in the north of the country in order to define appropriate strategies to effectively treat the affected population.
  
  
  RESULTS
  We designed a community-based survey using the Lot Quality Assurance Sampling method to classify the prevalence of active yaws in 14 groups of villages (lots). The classification into high, moderate, or low yaws prevalence corresponded to World Health Organization prevalence thresholds for identifying appropriate operational treatment strategies. Active yaws cases were defined by suggestive clinical signs and positive rapid plasma reagin and Treponema pallidum hemagglutination serological tests. The overall prevalence in the study area was 4.7% (95% confidence interval: 3.4-6.0). Two of 14 lots had high prevalence (>10%), three moderate prevalence (5-10%) and nine low prevalence (<5%.).
  
  
  CONCLUSIONS
  Although yaws is no longer a World Health Organization priority disease, the presence of yaws in a region where it was supposed to be eradicated demonstrates the importance of continued surveillance and control efforts. Yaws should remain a public health priority in countries where previously it was known to be endemic. The integration of sensitive surveillance systems together with free access to effective treatment is recommended. As a consequence of our study results, more than 16,000 people received free treatment against yaws.
authors.affiliation: Epicentre, Paris, France. sgerstl@aol.com
authors.forename: Sibylle
authors.initials: S
authors.lastname: Gerstl
authors.forename: Gédeon
authors.initials: G
authors.lastname: Kiwila
authors.forename: Mehul
authors.initials: M
authors.lastname: Dhorda
authors.forename: Sylvaine
authors.initials: S
authors.lastname: Lonlas
authors.forename: Mark
authors.initials: M
authors.lastname: Myatt
authors.forename: Benoît Kebela
authors.initials: BK
authors.lastname: Ilunga
authors.forename: Denis
authors.initials: D
authors.lastname: Lemasson
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Szumilin
authors.forename: Philippe J
authors.initials: PJ
authors.lastname: Guerin
authors.forename: Laurent
authors.initials: L
authors.lastname: Ferradini
mesh_terms: D015023:Democratic Republic of the Congo / Q000453:epidemiology; D006801:Humans; D055810:Lot Quality Assurance Sampling; D015995:Prevalence; D011786:Quality Control; D015001:Yaws / Q000453:epidemiology*