title: Giardia duodenalis genotypes among schoolchildren and their families and pets in urban and rural areas of Sinaloa, Mexico.
abstract: BACKGROUND
  Giardiasis is a human health concern worldwide, especially among schoolchildren. Giardia duodenalis genotypes A and B are infective to humans, but their zoonotic potential remains controversial. In Mexico, the most prevalent genotype is A, but B was also detected in southeastern Mexico. In Sinaloa state, northwestern Mexico, giardiasis is highly prevalent, but Giardia genotypes have been poorly studied.
  
  
  METHODS
  This study aimed to investigate the distribution and clinical-epidemiological correlation of G. duodenalis genotypes in schoolchildren and their families and pets in urban and rural areas of Sinaloa state, Mexico.
  
  
  RESULTS
  Among 395 schoolchildren (274 urban, 121 rural), 76 (49 urban, 27 rural) were infected with G. duodenalis. In total, 22 families (15 urban, 7 rural) of infected schoolchildren, consisting of 60 family members (41 urban, 19 rural) and 21 pet dogs (15 urban, 6 rural) were examined; 10 family members (5 urban, 5 rural) and 5 pet dogs (3 urban, 2 rural) of 10 families (6 urban, 4 rural) were infected. After PCR-RFLP analyses of vsp417 and gdh genes, genotype prevalence among infected urban schoolchildren was 79.5% AI, 12.8% AII, and 7.7% mixed AI+B. However, only AI genotype was found in family members and pets. In the rural area, only the AI genotype was detected. Genotypes were not correlated with clinical manifestations.
  
  
  CONCLUSIONS
  This paper shows the presence of B genotype in northwestern Mexico for the first time. Detection of AI genotype in dogs suggested the possible role of dogs as the reservoir for human giardiasis in Sinaloa, Mexico.
authors.affiliation: Autonomous University of Sinaloa (UAS) Sinaloa, Mexico. patriciacgarcia.c@gmail.com.
authors.forename: Patricia Catalina
authors.initials: PC
authors.lastname: García-Cervantes
authors.forename: María Elena
authors.initials: ME
authors.lastname: Báez-Flores
authors.forename: Francisco
authors.initials: F
authors.lastname: Delgado-Vargas
authors.forename: Martha
authors.initials: M
authors.lastname: Ponce-Macotela
authors.forename: Yukifumi
authors.initials: Y
authors.lastname: Nawa
authors.forename: María Del-Carmen
authors.initials: MD
authors.lastname: De-la-Cruz-Otero
authors.forename: Mario N
authors.initials: MN
authors.lastname: Martínez-Gordillo
authors.forename: Sylvia Páz
authors.initials: SP
authors.lastname: Díaz-Camacho
mesh_terms: D000818:Animals; D002648:Child; D004285:Dogs; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D016829:Giardia lamblia / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D005873:Giardiasis / Q000453:epidemiology / Q000469:parasitology* / Q000662:veterinary*; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D017720:Molecular Epidemiology; D058889:Molecular Typing; D057805:Pets; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D015995:Prevalence; D012424:Rural Population; D011795:Surveys and Questionnaires; D014505:Urban Population