Assessment microbial risks for the presence of Cryptosporidium spp. and Giardia spp. based on the surveillance of the water supply systems in Colombia, 2014–2018

Cryptosporidium spp. and Giardia spp. cause gastrointestinal diseases of zoonotic origin as well transmitted from person to person, being various reported outbreaks associated with water. The infecting (oo)cyst forms of these parasites are highly resistant to water treatments such as chlorine disinfection and fast filtration. The objective of this study was to assess the microbial risk of infection and symptomatic illness by the ingestion of Giardia spp. and Cryptosporidium spp. in water for human consumption in Colombia, based on the results of water quality surveillance. The detection method was according to the USEPA method 1623. Concentration data of the different points of distribution were grouped according to the pathogen and type of treatment (no treatment; chlorine treatment; chlorine treatment + coagulant). Annual microbial risks of infection and symptomatic diseases were estimated using the quantitative microbial risk assessment approach that included parasite concentrations, the dose–response model, the ingestion rates of water by children and adults, and the morbidity rate of the diseases. The mean annual microbial risk of infection for Giardia spp. was 29.8% for treated water and 50.4% for untreated water, while being 6.0% and 17.7%, respectively, for Cryptosporidium spp. Microbial risk of symptomatic illness for Giardia spp, was 8.2% for treated water and 13.9% for untreated water, while being 3.6% and 10.6%, respectively, for Cryptosporidium spp. The estimated annual microbial risks of infection exceeded the acceptable value of 10 4 (0.01%) recommended by USEPA. Results obtained in this study suggest the need to reduce the microbial risk of infection to protozoan parasites by improving the water treatment, by adopting better handling practices for livestock manure and treatment processes of human feces.

• Autores: Guzmán Barragan, Blanca Lisseth; de Souza Lauretto, Marcelo; Razzolini, Maria Tereza Pepe; Nardocci, Adelaide Cássia; Marimón , Karen
• Tipo de recurso: Article of investigation
• Fecha de publicación: 2022
• Institución: Universidad de Ciencias Aplicadas y Ambientales U.D.C.A
• Repositorio: Repositorio Institucional UDCA
• Idioma: eng
• OAI Identifier: oai:repository.udca.edu.co:11158/5067
• Acceso en línea: https://repository.udca.edu.co/handle/11158/5067; https://doi.org/10.1002/wer.10776
• Palabra clave: Niños; Criptosporidiosis; Giardia; Abastecimiento de Agua
• Rights: openAccess
• License: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode.es