title: Epidemiology of leptospira transmitted by rodents in southeast Asia.
abstract: BACKGROUND
  Leptospirosis is the most common bacterial zoonoses and has been identified as an important emerging global public health problem in Southeast Asia. Rodents are important reservoirs for human leptospirosis, but epidemiological data is lacking.
  
  
  RESULTS
  We sampled rodents living in different habitats from seven localities distributed across Southeast Asia (Thailand, Lao PDR and Cambodia), between 2009 to 2010. Human isolates were also obtained from localities close to where rodents were sampled. The prevalence of Leptospira infection was assessed by real-time PCR using DNA extracted from rodent kidneys, targeting the lipL32 gene. Sequencing rrs and secY genes, and Multi Locus Variable-number Tandem Repeat (VNTR) analyses were performed on DNA extracted from rat kidneys for Leptospira isolates molecular typing. Four species were detected in rodents, L. borgpetersenii (56% of positive samples), L. interrogans (36%), L. kirschneri (3%) and L. weilli (2%), which were identical to human isolates. Mean prevalence in rodents was approximately 7%, and largely varied across localities and habitats, but not between rodent species. The two most abundant Leptospira species displayed different habitat requirements: L. interrogans was linked to humid habitats (rice fields and forests) while L. borgpetersenii was abundant in both humid and dry habitats (non-floodable lands).
  
  
  CONCLUSIONS
  L. interrogans and L. borgpetersenii species are widely distributed amongst rodent populations, and strain typing confirmed rodents as reservoirs for human leptospirosis. Differences in habitat requirements for L. interrogans and L. borgpetersenii supported differential transmission modes. In Southeast Asia, human infection risk is not only restricted to activities taking place in wetlands and rice fields as is commonly accepted, but should also include tasks such as forestry work, as well as the hunting and preparation of rodents for consumption, which deserve more attention in future epidemiological studies.
authors.affiliation: INRA, CBGP, Campus international de Baillarguet, CS 30016, Montferrier-sur-Lez, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Cosson
authors.affiliation: Institut Pasteur, Unité de Biologie des Spirochètes, National Reference Center and WHO Collaborating Center for Leptospirosis, Paris, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Picardeau
authors.affiliation: INRA, CBGP, Campus international de Baillarguet, CS 30016, Montferrier-sur-Lez, France.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Mielcarek
authors.affiliation: INRA, CBGP, Campus international de Baillarguet, CS 30016, Montferrier-sur-Lez, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Tatard
authors.affiliation: INRA, CBGP, Campus international de Baillarguet, CS 30016, Montferrier-sur-Lez, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Chaval
authors.affiliation: Mahidol University, Faculty of Medecine, Siriraj Hospital, Bangkok, Thailand.
authors.forename: Yupin
authors.initials: Y
authors.lastname: Suputtamongkol
authors.affiliation: Institut Pasteur in Cambodia, Virology Unit, Réseau International des Instituts Pasteur, Phnom Penh, Cambodia.
authors.forename: Philippe
authors.initials: P
authors.lastname: Buchy
authors.affiliation: Kasetsart University, Department of Parasitology, Faculty of Veterinary Medicine, Bangkok, Thailand.
authors.forename: Sathaporn
authors.initials: S
authors.lastname: Jittapalapong
authors.affiliation: IRD, ESPACE-DEV (IRD, UM2, UR, UAG), Station SEAS-OI, F-97410 Saint-Pierre, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Herbreteau
authors.affiliation: Institut des Sciences de l'Evolution, CNRS-IRD-UM2, Université de Montpellier 2, Montpellier, France; CIRAD, UR AGIRs, Montpellier, France; Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Ratchathevi, Thailand.
authors.forename: Serge
authors.initials: S
authors.lastname: Morand
mesh_terms: D000818:Animals; D002160:Cambodia / Q000453:epidemiology; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004197:Disease Reservoirs; D005260:Female; D005838:Genotype; D006801:Humans; D007812:Laos / Q000453:epidemiology; D007919:Leptospira / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D007922:Leptospirosis / Q000453:epidemiology* / Q000382:microbiology / Q000662:veterinary*; D008297:Male; D018598:Minisatellite Repeats; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D058889:Molecular Typing; D015995:Prevalence; D012376:Rodent Diseases / Q000453:epidemiology* / Q000382:microbiology; D012377:Rodentia; D017422:Sequence Analysis, DNA; D013785:Thailand / Q000453:epidemiology; D015047:Zoonoses / Q000453:epidemiology* / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial