Quantification of Giardia and Cryptosporidium in water source for public supply and risk assessment of infection via water ingestion in a city of the Metropolitan Region of São Paulo (MRSP)

• Grant number: 12/12750-1
• Support Opportunities: Regular Research Grants
• Duration: December 01, 2012 - November 30, 2014
• Field of knowledge: Engineering - Sanitary Engineering
• Principal Investigator: Maria Tereza Pepe Razzolini
• Grantee: Maria Tereza Pepe Razzolini
• Host Institution: Faculdade de Saúde Pública (FSP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Microbiologically unsafe drinking water supplies are still a public health problem all over the world which represents a risk to human health. Giardia e Cryptosporidium protozoa draw attention because their resistance to a usual disinfection process, low infectious doses and ability to survive in the environment moreover their relevant role in the outbreaks of water-related diseases. Studies about waterborne outbreaks have shown that Cryptosporidium parvum e Giardia lamblia are the most prevalent. In order to protect human health, Brazilian regulation, Portaria 2.914/2011, consider mandatory the survey of these pathogenic protozoa in catchment points when E.coli concentration is superior than 103CUF/100mL, set turbidity values according to average of Cryptosporidium (<3,0 oocystos/L) in these catchment points and establish that this average must be obtained considering a minimal number of 24 samples collected in a minimal period of one year and maximum of two years. This regulation goes further when establish that a systematic assessment is required focusing on health risks and aiming the implementation of the Water Safety Plan. Methods: Water samples will be collected from Ribeirão dos Cristais river in the catchment point to before treatment during 12 months in a weekly frequency, totalizing 48 samples. The collection and analysis will be carried out according to EPA - Method 1623,2005. Determination of E. coli will be performed by chromogenic assay using kit Colilert (Iddex), follow the Standards Methods (21st ed. 2005), SM 9223. Probability of infection will be performed using exponential dose response model for Giardia and Cryptosporidium. The risk model will be subjected to a Monte Carlo uncertainty analysis to elucidate the uncertainties in the QMRA. Expected results: Collaborating with data to support discussions about quality standards and achieve background to elaborate or review the current quality standards regarding waters as well as estimate the probability of infection due to exposure to Giardia and Cryptosporidium via water ingestion. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BATAIERO, M. O.; ARAUJO, R. S.; NARDOCCI, A. C.; MATTE, M. H.; SATO, M. I. Z.; LAURETTO, M. S.; RAZZOLINI, M. T. P.. Quantification of Giardia and Cryptosporidium in surface water: a risk assessment and molecular characterization. WATER SCIENCE AND TECHNOLOGY-WATER SUPPLY, v. 19, n. 6, p. 1823-1830, SEP 2019. (12/12750-1)