Occurrence and Evaluation of Methodologies to Detect Cryptosporidium spp. in Treated Water in the Central-West Region of Brazil

Cryptosporidium spp. are an emerging pathogen responsible for a large number of diarrhea outbreaks in humans throughout the world. However, the occurrence of epidemic outbreaks caused by this agent in Brazil is poorly known and still needs more attention mainly in the Central-West Region of Brazil, where yet are not studied. Furthermore, there is a need for cheaper or faster methods for detecting Cryptosporidium spp. (given the cost of Envirocheck (R) filters and IMS kits). Thus, the implementation of standard techniques that enable the identification and quantification of this agent for further study of environmental samples is important. This study aimed at evaluating and comparing immunological techniques for detection of antigen and a real-time PCR for detection and differentiation of Cryptosporidium spp. in samples of treated water. Samples were collected directly from the taps at the entrance of residences and concentrated by a positively charged membrane filter. Oocysts of Cryptosporidium spp. were detected by direct immunofluorescence, ELISA and real-time PCR techniques, and the results were positive in 56.3 % (18/32), 28.1 % (9/32) and 50.0 % (16/32), respectively. The survey results showed for the first time the presence of Cryptosporidium spp. in treated water in the Central-West Region of Brazil. Although real-time PCR showed less positive, it is the one that enables the identification of the species and less expensive when processing a large number of samples. Probably, it would be better to use both techniques, due to their own virtues.