Giardia sp. cysts and Cryptosporidium spp. oocysts dynamics in southeast Brazil: occurrence in surface water and removal in water treatment processes

Abstract

Raw water and filtered effluent of three drinking water treatment plants (WTP) at a town in Minas Gerais State, southeast Brazil, were monitored over a one-year period for Giardia, Cryptosporidium, microbiological and physical-chemical water quality indicators. High densities of Giardia and Cryptosporidium were detected in two source waters, ranging from 2.0–140 cysts/L and 4.0–510 oocysts/L. Giardia and Cryptosporidium (oo)cyst concentration was not consistently associated with most of the parameters analysed, turbidity being the most promising indicator. It also seems that Giardia and Cryptosporidium concentration was influenced by rainfall. Giardia cysts and Cryptosporidium oocysts were significantly associated in both waters, suggesting a similar pattern of occurrence and common contamination sources. In two of the three water treatment plants analyzed, Giardia and Cryptosporidium were detected in filtered effluents, also in high densities, ranging from 0.066 to 5.5 cysts/L and 0.066 to 13.2 oocysts/L, respectively. Statistical trials to associate protozoa and indicator removal failed in nearly all cases. Nevertheless, the results are interpreted as neither reaffirming nor negating the use of turbidity as a protozoa removal indicator.

Detecção de cistos de Giardia spp. e oocistos de Cryptosporidium spp. na água bruta das estações de tratamento no município de Blumenau, SC, Brasil

“…Tanto a ETA I como a ETA II utilizam água do mesmo manancial -Rio Itajaí-Açu (Tabela 1). Os valores apresentam-se semelhantes aos compilados por Bastos et al (2004), que verificaram a ocorrência de elevadas concentrações de cistos e oocistos em diversos mananciais no Brasil. Sato et al (2013) descrevem que num total de 206 amostras coletadas em 28 locais no Estado de São Paulo, Giardia spp.…”

Improvement of detection method of Cryptosporidium and Giardia in reclaimed water

“…Cryptosporidium and Giardia were widely detected in water sources [1][2][3], drinking water [4], wastewater and reclaimed water [5][6][7][8][9]. The positive detection results of Cryptosporidium in reclaimed water range from 40% to 70% [5,6].…”

Bioagentes patogênicos em águas residuárias: destaque para giardia spp., cryptosporidium spp. bactérias indicadoras e vírus entéricos

“…e os oocistos de Cryptosporidium spp. mereceram destaque, considerando a escassez de dados disponíveis sobre a inativação desses protozoários por meio de tratamento de esgoto (ROBERTSON et al, 2000;CARDOSO et al, 2003;HELLER et al, 2004;WEN et al, 2009;MEDEIROS, 2010).…”

“…Bastos et al (2004) encontraram 2,0 a 140 cistos/L e de 4,0 a 510 00 cistos/L em mananciais de abastecimento da cidade de Viçosa -MG Hachich et al (2004),. ao avaliar 10 bacias hidrográficas no Estado de São Paulo, detectaram a presença de Giardia spp.…”