Despite the large amounts of freshwater available in Brazil, the deterioration of surface water can represent a risk of waterborne disease for national and international tourists. The main goal of this study was to assess the quality of drinking water in the triple border region of Brazil before and after being treated in water treatment plants (WTPs) and in Municipal Early Childhood Education Centers (MECECs), in terms of parasitological, microbiological, and physical–chemical aspects. Different water samples were monitored: raw water (RW), treated water (TW), and tap water from the MECECs, giving 60 samples in total, to investigate the presence of Giardia and Cryptosporidium, microbiological indicators, Pseudomonas aeruginosa, and antimicrobial resistance profiles using conventional microbiological assays and parasitological, immunological, and molecular techniques. The results obtained were compared with the reference values recommended by the legislation of drinking water in Brazil. For the first time, contamination by Cryptosporidium and Giardia was demonstrated in RW used to supply WTPs, in TW of Foz do Iguaçu, and in water destined for consumption by children. A total of 52 bacterial isolates were obtained, with high percentages of multidrug resistance to antibiotics, including a carbapenem-resistant profile, highlighting the need to improve quality control standards.

A transmissão de protozoários patogênicos pela água é um dos mais relevantes problemas de saúde pública na atualidade. Numerosos surtos epidêmicos causados pelos protozoários Giardia e Cryptosporidium ocorreram ao redor do mundo em passado recente. Entretanto, os métodosutilizados para a detecção de cistos e oocistos em amostras de água são influenciados por características físico-químicas da matriz de água, como a turbidez. Esta revisão apresenta umaanálise crítica das diferentes metodologias de concentração de cistos de Giardia e de oocistos de Cryptosporidium em amostras de águas destinadas ao consumo humano. A implantação do monitoramento desses protozoários é uma necessidade no Brasil dada a recente revisão da Portaria nº 518 do Ministério da Saúde.