title: Leptospirosis in Mexico: Epidemiology and Potential Distribution of Human Cases.
abstract: BACKGROUND
  Leptospirosis is widespread in Mexico, yet the potential distribution and risk of the disease remain unknown.
  
  
  RESULTS
  We analysed morbidity and mortality according to age and gender based on three sources of data reported by the Ministry of Health and the National Institute of Geography and Statics of Mexico, for the decade 2000-2010. A total of 1,547 cases were reported in 27 states, the majority of which were registered during the rainy season, and the most affected age group was 25-44 years old. Although leptospirosis has been reported as an occupational disease of males, analysis of morbidity in Mexico showed no male preference. A total number of 198 deaths were registered in 21 states, mainly in urban settings. Mortality was higher in males (61.1%) as compared to females (38.9%), and the case fatality ratio was also increased in males. The overall case fatality ratio in Mexico was elevated (12.8%), as compared to other countries. We additionally determined the potential disease distribution by examining the spatial epidemiology combined with spatial modeling using ecological niche modeling techniques. We identified regions where leptospirosis could be present and created a potential distribution map using bioclimatic variables derived from temperature and precipitation. Our data show that the distribution of the cases was more related to temperature (75%) than to precipitation variables. Ecological niche modeling showed predictive areas that were widely distributed in central and southern Mexico, excluding areas characterized by extreme climates.
  
  
  CONCLUSIONS
  In conclusion, an epidemiological surveillance of leptospirosis is recommended in Mexico, since 55.7% of the country has environmental conditions fulfilling the criteria that favor the presence of the disease.
authors.affiliation: Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico; Centro de Medicina Tropical, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Sokani
authors.initials: S
authors.lastname: Sánchez-Montes
authors.affiliation: Museo de Zoología "Alfonso L. Herrera", Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Deborah V
authors.initials: DV
authors.lastname: Espinosa-Martínez
authors.affiliation: Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico; Centro de Medicina Tropical, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico; Museo de Zoología "Alfonso L. Herrera", Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: César A
authors.initials: CA
authors.lastname: Ríos-Muñoz
authors.affiliation: Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico; Centro de Medicina Tropical, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Miriam
authors.initials: M
authors.lastname: Berzunza-Cruz
authors.affiliation: Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico; Centro de Medicina Tropical, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Becker
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000818:Animals; D002648:Child; D002675:Child, Preschool; D017753:Ecosystem; D005260:Female; D005843:Geography; D006801:Humans; D007223:Infant; D007922:Leptospirosis / Q000453:epidemiology*; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D008954:Models, Biological; D058069:Neglected Diseases / Q000453:epidemiology; D011891:Rain; D012189:Retrospective Studies; D012621:Seasons; D017678:Sex Distribution; D016019:Survival Analysis; D013696:Temperature; D055815:Young Adult; D015047:Zoonoses