Department of Sanitation and Environmental Health, Sergio Arouca National School of Public Health, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, Brazil.
Laboratory of Comparative and Environmental Virology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro 21040-900, Brazil.
J Appl Microbiol. 2024 Jul 2;135(7). doi: 10.1093/jambio/lxae177.
This study aimed to assess the use of cross-assembled phage (crAssphage) as an endogenous control employing a multivariate normalization analysis and its application as a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) data normalizer.
A total of 188 twelve-hour composite raw sewage samples were obtained from eight wastewater treatment plants (WWTP) during a 1-year monitoring period. Employing the N1 and N2 target regions, SARS-CoV-2 RNA was detected in 94% (177) and 90% (170) of the samples, respectively, with a global median of 5 log10 genomic copies per liter (GC l-1). CrAssphage was detected in 100% of the samples, ranging from 8.29 to 10.43 log10 GC l-1, with a median of 9.46 ± 0.40 log10 GC l-1, presenting both spatial and temporal variabilities.
Although SARS-CoV-2 data normalization employing crAssphage revealed a correlation with clinical cases occurring during the study period, crAssphage normalization by the flow per capita per day of each WWTP increased this correlation, corroborating the importance of normalizing wastewater surveillance data in disease trend monitoring.
本研究旨在评估使用交叉组装噬菌体（crAssphage）作为内源性对照，采用多元归一化分析，并将其应用于严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）数据归一化。
在为期一年的监测期间，从 8 个污水处理厂（WWTP）共采集了 188 个 12 小时的复合原始污水样本。利用 N1 和 N2 靶区域，分别在 94%（177 个）和 90%（170 个）的样本中检测到 SARS-CoV-2 RNA，全球中位数为每升基因组拷贝数 5 log10（GC l-1）。crAssphage 在 100%的样本中被检测到，范围为 8.29 至 10.43 log10 GC l-1，中位数为 9.46±0.40 log10 GC l-1，呈现出空间和时间上的变异性。
尽管使用 crAssphage 对 SARS-CoV-2 数据进行归一化显示与研究期间发生的临床病例存在相关性，但通过每个 WWTP 的人均日流量对 crAssphage 进行归一化增加了这种相关性，证实了对污水监测数据进行归一化对疾病趋势监测的重要性。
