Table_2_SARS-CoV-2 excretion kinetics in nasopharyngeal and stool samples from the pediatric population.DOCX

BackgroundThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for serious respiratory infections in humans. Even in the absence of respiratory symptoms, gastrointestinal (GI) signs were commonly reported in adults and children. Thus, oral–fecal transmission was suspected as a possible route of infection. The objective of this study was to describe RNA shedding in nasopharyngeal and stool samples obtained from asymptomatic and symptomatic children and to investigate virus viability.
MethodsThis study included 179 stool and 191 nasopharyngeal samples obtained from 71 children, which included symptomatic (n = 64) and asymptomatic (n = 7) ones. They were collected every 7 days from the onset of the infection until negativation. Viral RNA was detected by real-time RT-PCR, targeting the N and ORF1 genes. Whole-genome sequencing was performed for positive cases. Viral isolation was assessed on Vero cells, followed by molecular detection confirmation.
ResultsAll cases included in this study (n = 71) were positive in their nasopharyngeal samples. SARS-CoV-2 RNA was detected in 36 stool samples obtained from 15 out of 71 (21.1%) children; 13 were symptomatic and two were asymptomatic. Excretion periods varied from 7 to 21 days and 7 to 14 days in nasopharyngeal and fecal samples, respectively. Four variants were detected: Alpha (n = 3), B.1.160 (n = 3), Delta (n = 7), and Omicron (n = 1). Inoculation of stool samples on cell culture showed no specific cytopathic effect. All cell culture supernatants were negative for RT-qPCR.
ConclusionOur study demonstrated nasopharyngeal and fecal shedding of SARS-CoV-2 RNA by children up to 21 and 14 days, respectively. Fecal shedding was recorded in symptomatic and asymptomatic children. Nevertheless, SARS-CoV-2 was not isolated from positive stool samples.

背景：严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）可引发人类严重呼吸道感染。即便无呼吸道症状，成人与儿童仍常出现胃肠道（GI）相关体征。因此，粪口传播被怀疑为可能的感染途径。本研究旨在描述无症状及有症状儿童的鼻咽拭子与粪便样本中的RNA排毒情况，并探究病毒的存活能力。
方法：本研究纳入71名儿童的179份粪便样本与191份鼻咽拭子样本，其中有症状儿童64例、无症状儿童7例。自感染发病起，每7天采集一次样本，直至样本检测结果转阴。采用针对N基因与ORF1基因的实时逆转录聚合酶链反应（real-time RT-PCR）检测病毒RNA。对检测结果呈阳性的样本开展全基因组测序。采用Vero细胞进行病毒分离实验，随后通过分子检测对结果进行确认。
结果：本研究纳入的71例儿童的鼻咽拭子样本均呈阳性。71名儿童中有15名（占比21.1%）的36份粪便样本检测出SARS-CoV-2 RNA，其中13例为有症状儿童，2例为无症状儿童。鼻咽拭子样本的排毒时长为7至21天，粪便样本的排毒时长为7至14天。共检测到4种病毒变异株：Alpha株3例、B.1.160株3例、Delta株7例以及Omicron株1例。将粪便样本接种至细胞培养体系后未观察到特异性细胞病变效应，所有细胞培养上清液的RT-qPCR检测结果均为阴性。
结论：本研究证实，儿童的鼻咽拭子与粪便样本中的SARS-CoV-2 RNA排毒时长分别可达21天与14天。有症状及无症状儿童均可出现粪便排毒现象。但本研究未能从检测结果呈阳性的粪便样本中分离出SARS-CoV-2。