Tonani K A A, Padula J A, Julião F C, Fregonesi B M, Alves R I S, Sampaio C F, Beda C F, Hachich E M, Segura-Muñoz S I
Laboratory of Ecotoxicology and Environmental Parasitology, Ribeirão Preto College of Nursing, University of São Paulo, Ribeirão Preto, SP, Brazil;
J Parasitol. 2013 Dec;99(6):1144-7. doi: 10.1645/12-121.1. Epub 2013 May 29.
Abstract : The persistence of Giardia, Cryptosporidium, Rotavirus, and Adenovirus in samples of raw and treated sewage collected monthly in 2010 at the Biological Wastewater Treatment Plant of Ribeirão Preto, SP, Brazil, was analyzed. The USEPA Method 1623 was used to detect and quantify Giardia and Cryptosporidium. An enzyme immunoassay was carried out to test Rotavirus and Adenovirus antigen optical density (Rotascreen® and Adenoscreen®). The results show a significant decrease in the concentrations of Giardia, Rotavirus and Adenovirus (P < 0.05) and a trend of decreasing Cryptosporidium densities, without statistical significance. Giardia concentrations ranged from 120 to 2,200 cysts/L in raw sewage and from 0.45 to 3.5 cysts/L in treated sewage. Cryptosporidium concentration ranged from undetectable to 28.9 oocysts/L in raw sewage and undetectable to 1.05 oocysts/L in treated sewage. Rotavirus presented absorbance values that ranged from 1.17 ± 0.81 in raw sewage to 0.46 ± 0.32 in treated sewage. Adenovirus, in turn, presented absorbance values of 0.64 ± 0.20 in raw sewage and of 0.45 ± 0.04 in treated sewage. There was no significant seasonal tendency observed in the distribution of protozoa (oo)cysts and in the viral antigen density in the monthly sewage samples during 2010 (P > 0.05). Even though these pathogenic agents decreased after treatment, the remaining loads observed in treated sewage can reach the watercourses receiving it. Giardia, Cryptosporidium, Rotavirus, and Adenovirus are pathogens with very low infectious doses, representing a public health risk especially for vulnerable groups, such as children living near these watercourses and homeless people using this water for various purposes. Studies addressing the environmental persistence of opportunistic pathogens in watercourses are hugely important in the public health sphere, especially in developing countries, where economic, social, cultural, and environmental factors still persist that are favorable to population's exposure to diarrhea-causing agents.
对2010年每月在巴西圣保罗州里贝朗普雷图生物污水处理厂采集的原污水和处理后污水样本中贾第虫、隐孢子虫、轮状病毒和腺病毒的持久性进行了分析。采用美国环境保护局（USEPA）方法1623检测和定量贾第虫和隐孢子虫。进行酶免疫测定以检测轮状病毒和腺病毒抗原光密度（Rotascreen®和Adenoscreen®）。结果显示，贾第虫、轮状病毒和腺病毒的浓度显著降低（P < 0.05），隐孢子虫密度呈下降趋势，但无统计学意义。原污水中贾第虫浓度范围为120至2200个包囊/升，处理后污水中为0.45至3.5个包囊/升。原污水中隐孢子虫浓度范围为未检出至28.9个卵囊/升，处理后污水中为未检出至1.05个卵囊/升。轮状病毒的吸光度值范围从原污水中的1.17±0.81到处理后污水中的0.46±0.32。腺病毒方面，原污水中的吸光度值为0.64±0.20，处理后污水中的为0.45±0.04。2010年每月污水样本中，原生动物（卵）囊的分布和病毒抗原密度未观察到显著的季节性趋势（P > 0.05）。尽管这些病原体在处理后有所减少，但处理后污水中观察到的残留负荷仍可到达接纳该污水的水道。贾第虫、隐孢子虫、轮状病毒和腺病毒是感染剂量极低的病原体，对弱势群体，如居住在这些水道附近的儿童和将此水用于各种用途的无家可归者，构成公共卫生风险。研究机会性病原体在水道中的环境持久性在公共卫生领域非常重要，特别是在发展中国家，那里经济、社会、文化和环境因素仍然存在，有利于人群接触致泻病原体。
