The aim of this study was to detect, quantify, and assess the risk of infection and illness for Group A Rotavirus (RVA) in the watersheds of the Santa Lucia and Uruguay rivers in Uruguay. Monthly sampling was carried out for one year in six sites in the watershed of the Santa Lucía River and four in the Uruguay River. All the collection sites are used for recreational activities. Viral concentration was performed with the adsorption–elution method, and detection and quantification of RVA was carried out by TaqMan quantitative PCR (qPCR). Quantitative microbial risk assessment was applied to estimate the daily and annual risk of RVA infection, as well as the daily risk of illness considering direct exposure through recreational activity. RVA was detected in 42% (20/48) of the analyzed samples in the Uruguay River and 40% (29/72) in the Santa Lucía River. The virus was present in all the analyzed points in both watersheds. A pattern of seasonality, characterized by a higher detection frequency of the virus during coldest month of the year, was observed in both basins. The mean concentration for RVA was 1.3 × 10⁵ genomic copies/L. The microbiological risk assessment shows that Santa Lucía watershed presented the highest daily risk of infection (6.41E–01) and illness (3.20E–01) estimated for the point downstream of Florida City; meanwhile for Uruguay River, the highest probabilities of infection (6.82E–01) and illness (3.41E–01) were estimated for the collection site for drinking water intake in Salto city. These results suggest that RVA contamination of these important rivers negatively impact on their microbiological quality since they are used for recreation and drinking water intake, demonstrating that the disposal of waste from cities located in their riverside confers a constant threat of infection for the general population, especially for children.

中文翻译：

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乌拉圭河流中甲型轮状病毒的检测，定量和微生物风险评估。

这项研究的目的是检测，量化和评估乌拉圭圣卢西亚河和乌拉圭河流域的A组轮状病毒（RVA）的感染和疾病风险。在圣卢西亚河分水岭的六个地点和乌拉圭河的四个地点进行了为期一年的每月采样。所有收集地点均用于娱乐活动。用吸附-洗脱方法进行病毒浓缩，通过TaqMan定量PCR（qPCR）进行RVA的检测和定量。考虑到通过娱乐活动直接接触，使用定量微生物风险评估来估计RVA感染的每日和年度风险以及疾病的每日风险。在乌拉圭河中42％（20/48）的分析样品中检测到RVA，在圣卢西亚河中40％（29/72）的样品中检测到RVA。该病毒存在于两个流域的所有分析点中。在两个流域都观察到季节性模式，其特征是在一年中最冷的月份中病毒的检测频率较高。RVA的平均浓度为1.3×10^5个基因组拷贝/升。微生物风险评估表明，圣塔卢西亚流域的每日感染风险（6.41E-01）和疾病（3.20E-01）最高，据佛罗里达市下游地区估计。同时，对于乌拉圭河，萨尔托市饮用水收集站的感染率最高（6.82E-01）和疾病（3.41E-01）。这些结果表明，由于这些重要河流的RVA污染被用于娱乐和饮水，因此对其微生物质量产生了负面影响，这表明从位于其河畔的城市处置废物会给广大民众带来持续的感染威胁，特别是对于儿童。