Enteric viruses in the aquatic environment are a concern due to the potential for waterborne disease transmission to humans. In Nepal, the Bagmati River serves as a source of drinking and irrigation water; therefore, the detection of waterborne enteric pathogens is integral to maintaining human health. The objective of this study was to quantify the crAssphage marker in surface water samples from the Bagmati River between November 2015 and September 2016. Concentrations of crAssphage were then compared to those of other enteric viruses and indicator organisms found in the samples in order to examine the potential of crAssphage as a marker for fecal contamination. CrAssphage was detected in 17% (1/6) of samples from Sundarijal, 100% (6/6) of samples from Thapathali, and 100% (6/6) samples from Chovar, with the highest average concentrations recorded in May 2016 and the lowest average concentrations recorded in September 2016. Overall, crAssphage was present in 72% (13/18) of samples and was strongly correlated with the presence of fecal indicator bacteria Escherichia coli (r = 0.89) and Enterococcus (r = 0.92) and several enteric viruses. The strongest viral correlations were to salivirus (r = 0.84), pepper mild mottle virus (r = 0.77), Aichi virus 1 (r = 0.75), enteroviruses (r = 0.76), and tobacco mosaic virus (r = 0.71). These results provide evidence for the potential use of crAssphage as a marker for human fecal contamination in river water.

中文翻译：

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CrAssphage标记物在尼泊尔河水中跟踪粪便污染的评估

在水生环境中的肠病毒是一个令人关注的问题，原因是水传播疾病有可能传播给人类。在尼泊尔，巴格马蒂河是饮用水和灌溉水的来源。因此，检测水性肠道病原体对于维持人类健康至关重要。这项研究的目的是量化2015年11月至2016年9月在巴格马蒂河地表水样品中的crAssphage标记。然后将crAssphage的浓度与样品中发现的其他肠道病毒和指示生物的浓度进行比较，以检查卵噬菌体作为粪便污染标志物的潜力。在来自Sundarijal的17％（1/6）样品，来自Thapathali的100％（6/6）样品和来自Chovar的100％（6/6）样品中检测到CrAssphage，大肠杆菌（r  = 0.89）和肠球菌（r  = 0.92）以及几种肠病毒。病毒相关性最强的是唾液病毒（r  = 0.84），胡椒轻斑驳病毒（r  = 0.77），爱知病毒1（r  = 0.75），肠病毒（r  = 0.76）和烟草花叶病毒（r  = 0.71）。这些结果提供了证明可能将猪噬菌体用作河水中人粪便污染的标志物。