title: Haemophilus ducreyi: from sexually transmitted infection to skin ulcer pathogen.
abstract: OBJECTIVE
  This article provides an overview of the biology, epidemiology, clinical features, diagnostic tests, and treatment of Haemophilus ducreyi infection, with special reference to the decline of chancroid and the recent emergence of H. ducreyi as a pathogen responsible for chronic limb ulceration clinically similar to yaws.
  
  
  RESULTS
  Chancroid has declined in importance as a sexually transmitted infection in most countries where it was previously endemic. Chancroid may be caused by either class I or class II H. ducreyi isolates; these two classes diverged from each other approximately 1.95 million years ago. H. ducreyi has recently emerged as a cause of chronic skin ulceration in the Pacific region and Africa. Based on sequencing of whole genomes and defined genetic loci, it appears that the cutaneous H. ducreyi strains diverged from the class I genital strains relatively recently.
  
  
  CONCLUSIONS
  H. ducreyi should be considered as a major cause of chronic limb ulceration in both adults and children and appropriate molecular diagnostic assays are required to determine ulcer aetiology. The high prevalence of H. ducreyi-related cutaneous ulceration in yaws-endemic countries has challenged the validity of observational surveys to monitor the effectiveness of the WHO's yaws eradication campaign.
authors.affiliation: aCentre for Infectious Diseases and Microbiology bMarie Bashir Institute for Infectious Diseases and Biosecurity, Westmead Clinical School, University of Sydney, Sydney cWestern Sydney Sexual Health Centre, Parramatta, New South Wales, Australia dBarcelona Centre for International Health Research, Hospital Clínic, University of Barcelona, Barcelona, Spain.
authors.forename: David A
authors.initials: DA
authors.lastname: Lewis
authors.forename: Oriol
authors.initials: O
authors.lastname: Mitjà
mesh_terms: D000349:Africa / Q000453:epidemiology; D002602:Chancroid / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology* / Q000517:prevention & control; D019353:Endemic Diseases; D006191:Haemophilus ducreyi / Q000472:pathogenicity*; D006386:Hemagglutination Tests; D006801:Humans; D010139:Pacific Islands / Q000453:epidemiology; D015995:Prevalence; D012749:Sexually Transmitted Diseases / Q000453:epidemiology / Q000382:microbiology* / Q000517:prevention & control; D012883:Skin Ulcer / Q000382:microbiology* / Q000473:pathology; D015001:Yaws / Q000453:epidemiology*