title: Occurrence and quantitative microbial risk assessment of Cryptosporidium and Giardia in soil and air samples.
abstract: BACKGROUND
  Cryptosporidium oocysts and Giardia cysts can be transmitted by the fecal-oral route and may cause gastrointestinal parasitic zoonoses. These zoonoses are common in rural zones due to the parasites being harbored in fecally contaminated soil. This study assessed the risk of illness (giardiasis and cryptosporidiosis) from inhaling and/or ingesting soil and/or airborne dust in Potam, Mexico.
  
  
  METHODS
  To assess the risk of infection, Quantitative Microbial Risk Assessment (QMRA) was employed, with the following steps: (1) hazard identification, (2) hazard exposure, (3) dose-response, and (4) risk characterization.
  
  
  RESULTS
  Cryptosporidium oocysts and Giardia cysts were observed in 52% and 57%, respectively, of total soil samples (n=21), and in 60% and 80%, respectively, of air samples (n=12). The calculated annual risks were higher than 9.9 × 10(-1) for both parasites in both types of sample.
  
  
  CONCLUSIONS
  Soil and air inhalation and/or ingestion are important vehicles for these parasites. To our knowledge, the results obtained in the present study represent the first QMRAs for cryptosporidiosis and giardiasis due to soil and air inhalation/ingestion in Mexico. In addition, this is the first evidence of the microbial air quality around these parasites in rural zones.
authors.affiliation: Instituto Tecnológico de Sonora, Departamento de Biotecnología y Ciencias Alimentarias, 5 de febrero 818 Sur, colonia Centro CP 85000, Cd. Obregón, Sonora, Mexico.
authors.forename: Ana Paola
authors.initials: AP
authors.lastname: Balderrama-Carmona
authors.affiliation: Instituto Tecnológico de Sonora, Departamento de Biotecnología y Ciencias Alimentarias, 5 de febrero 818 Sur, colonia Centro CP 85000, Cd. Obregón, Sonora, Mexico. Electronic address: pablo.gortares@itson.edu.mx.
authors.forename: Pablo
authors.initials: P
authors.lastname: Gortáres-Moroyoqui
authors.affiliation: Instituto Tecnológico de Sonora, Departamento de Biotecnología y Ciencias Alimentarias, 5 de febrero 818 Sur, colonia Centro CP 85000, Cd. Obregón, Sonora, Mexico; Universidad Autónoma de Nuevo León, Facultad de Ciencias Químicas, San Nicolás de los Garza, NL, Mexico.
authors.forename: Luis Humberto
authors.initials: LH
authors.lastname: Álvarez-Valencia
authors.affiliation: Instituto Tecnológico de Sonora, Departamento de Biotecnología y Ciencias Alimentarias, 5 de febrero 818 Sur, colonia Centro CP 85000, Cd. Obregón, Sonora, Mexico.
authors.forename: Luciano
authors.initials: L
authors.lastname: Castro-Espinoza
authors.affiliation: Instituto Tecnológico de Sonora, Departamento de Biotecnología y Ciencias Alimentarias, 5 de febrero 818 Sur, colonia Centro CP 85000, Cd. Obregón, Sonora, Mexico.
authors.forename: Iram
authors.initials: I
authors.lastname: Mondaca-Fernández
authors.affiliation: Instituto Tecnológico de Sonora, Departamento de Biotecnología y Ciencias Alimentarias, 5 de febrero 818 Sur, colonia Centro CP 85000, Cd. Obregón, Sonora, Mexico.
authors.forename: José de Jesús
authors.initials: Jde J
authors.lastname: Balderas-Cortés
authors.affiliation: Centro de Investigación en Alimentación y Desarrollo, Departamento de Inocuidad Alimentaria, Culiacán, Sinaloa, Mexico.
authors.forename: Cristóbal
authors.initials: C
authors.lastname: Chaidez-Quiroz
authors.affiliation: Instituto Tecnológico de Sonora, Departamento de Biotecnología y Ciencias Alimentarias, 5 de febrero 818 Sur, colonia Centro CP 85000, Cd. Obregón, Sonora, Mexico.
authors.forename: María Mercedes
authors.initials: MM
authors.lastname: Meza-Montenegro
mesh_terms: D000328:Adult; D000388:Air / Q000469:parasitology*; D000818:Animals; D002648:Child; D002675:Child, Preschool; D003457:Cryptosporidiosis / Q000453:epidemiology* / Q000469:parasitology; D003458:Cryptosporidium / Q000254:growth & development / Q000302:isolation & purification*; D004781:Environmental Exposure; D005872:Giardia / Q000254:growth & development / Q000302:isolation & purification*; D005873:Giardiasis / Q000453:epidemiology* / Q000469:parasitology; D006801:Humans; D019570:Inhalation Exposure; D008800:Mexico; D033661:Oocysts; D018570:Risk Assessment; D012987:Soil / Q000469:parasitology*
chemical_list: D012987:Soil
keywords: Air; Cryptosporidium; Giardia; Microbiological risk; Soil