key: cord-0825050-zzoahk00 authors: Hua, Chun‐Zhen; Miao, Zi‐Ping; Zheng, Ji‐Shan; Huang, Qian; Sun, Qing‐Feng; Lu, Hong‐Ping; Su, Fei‐Fei; Wang, Wei‐Hong; Huang, Lie‐Ping; Xu, Zhi‐Wei; Ji, Le‐Dan; Zhang, Hong‐Ping; Yang, Xiao‐Wei; Li, Ming‐Hui; Mao, Yue‐Yan; Ying, Man‐Zhen; Ye, Sheng; Shu, Qiang; Chen, En‐Fu; Liang, Jian‐Feng; Wang, Wei; Chen, Zhi‐Min; Li, Wei; Fu, Jun‐Fen title: Epidemiological features and viral shedding in children with SARS‐CoV‐2 infection date: 2020-06-15 journal: J Med Virol DOI: 10.1002/jmv.26180 sha: a8b898d446ceb1d4fdc3b31f560465eb9e2bef40 doc_id: 825050 cord_uid: zzoahk00 BACKGROUND: A pandemic of SARS‐CoV‐2 infection broke out all over the world, however, epidemiological data and viral shedding in pediatric patients are limited. METHODS: We conducted a retrospective, multi‐center study, and followed up with all children from the families with SARS‐CoV‐2 infected members in Zhejiang Province, China. All infections were confirmed by testing the SARS‐CoV‐2 RNA with RT‐PCR method, and epidemiological data between children and adults in the same families was compared. Effect of antiviral therapy was evaluated observationally and fecal viral excretion times among groups with different antiviral regiments were compared with Kaplan Meier plot. RESULTS: By February 29, 2020, 1298 cases from 883 families were confirmed with SARS‐CoV‐2 infection and 314 of which were families with children. Incidence of infection in child close contacts was significantly lower than that in adult contacts (13.2% vs 21.2%). The mean age of 43 pediatric cases was 8.2 years and mean incubation period was 9.1 days. Forty (93.0%) were family clustering. Thirty‐three children had COVID‐19 (20 pneumonia) with mild symptoms and 10 were asymptomatic. Fecal SARS‐CoV‐2 RNA detection was positive in 91.4% (32/35) cases and some children had viral excretion time over 70 days. Viral clearance time was not different among the groups treated with different antiviral regiments. No subsequent infection was observed in family contacts of fecal‐viral‐excreting children. CONCLUSION: Children have lower susceptibility of SARS‐CoV‐2 infection, longer incubation and fecal viral excretion time. Positive results of fecal SARS‐CoV‐2 RNA detection were not used as indication for hospitalization or quarantine. This article is protected by copyright. All rights reserved. enrolled all pediatric cases in Zhejiang Province, which were about 30% more cases (≤14 years) than the previous study 11 . In addition to the similar clinical characteristic as described by Qiu et al., we have added analysis on the susceptibility of SARS-CoV-2 infection in children contacts and adult contacts in the same families, investigation on viral shedding and evaluation the effectiveness on viral clearance of different antiviral treatments by long time of follow-up. Our study addressed some of the most essential and un-answered questions that were not reported by Qiu et al. 11 . Thus, the objective of the current study was to describe the epidemiological and viral clearance aspects in all children from the families with SARS-CoV-2 infected members in Zhejiang province. A retrospective, multi-center study including all pediatric cases (≤14 years) with SARS-CoV-2 infection, accompanied by follow up, was designed in Zhejiang province, China. There was no selection of any sort on cases. Demographic information and epidemiological data of all pediatric cases were exacted from the electronic master database (updated daily) established by the Zhejiang Provincial CDC. All cases were confirmed based on positive results of a real-time reverse transcription PCR (RT-PCR) assay of SARS-CoV-2 RNA from respiratory specimens 12 and all cases with confirmed infection should be hospitalized at local designated hospitals according to the national policy. The epidemiological data was obtained from CDC records by Miao ZP (who was both health authorities from CDC and researchers in the study). Clinical data was obtained from the patients' medical records by the attending (who were researchers in the study too). Clinical Accepted Article outcomes were followed up (till now) after the children were discharged (outpatients follow up by attending and telephone follow up by Hua CZ). Children's epidemiological information was confirmed again with children's guardians by direct telephone communication during the follow-up process. The incubation period was from the initial exposure to the illness onset day. Initial exposure was defined as the day when children was exposed to the confirmed patients for those who occasionally visited; or previous 3 days when the first patient had illness onset in the family for those who lived together 13 . All data were cross-checked by two researchers (Hua CZ and Miao ZP). (T-043-R) and ethics commission of all designated hospitals for recruiting COVID-19 patients. Individual privacy was protected during the study. Oral consents were obtained from the guardians of the children. SPSS software 20.0 (IMM, US) was used in the study. Age and time variables were described as mean (SD) if they were normally distributed and compared with t test, or expressed as median (IQR) if they were not normally distributed and days in hospital among groups with different antiviral therapeutic regimens were compared with the Kruskal-Wallis test. Categorical variables were described as number (%) and the prevalence of SARS-CoV-2 infection was compared by χ 2 test between children group and adult group. Fisher's exact test was used in comparing the positive rates of RT-PCR results in feces among groups with different antiviral regimes. A two-sided α of Accepted Article less than 0.05 was considered statistically significant. Epidemic trend analysis was conducted with R software version 3.5.3 (R Foundation for Statistical Computing) The funder of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The corresponding authors had full access to all the data in the study and had final responsibility for the decision to submit for publication. All these 1298 cases were from 883 families excluding the prisoners, elderly people in gerocomium and students on campus, 714 families (80.9%) of which were successfully followed up and 314 families had 417 children living together. Two of which were neonates born by pregnant women with COVID-19. Specimens evaluated from umbilical cord blood, neonatal blood, stool, and nasopharynx specimen, all were negative for SARS-CoV-2 RNA by RT-PCR. The physical conditions of the children contacts and adult contacts from the 314 families with SARS-CoV-2 infected members in Zhejiang Province are shown in Table 1 . All SARS-CoV-2 infection cases in the present study were confirmed by real-time reverse transcription PCR assay Accepted Article in combination, and their gastrointestinal symptoms disappeared after lopinavir/ritonavir being removed or replaced with darunavir/cobicistat tablets. Liver function abnormality occurred in 3 patients after they received oral lopinavir/ritonavir and arbidol, and atomization inhalation with interferon-α2b (lopinavir/ritonavir was replaced with darunavir/cobicistatin one patient because of gastrointestinal symptoms). Thirty-six (83.7%, 36/43) children received chest computed tomography (CT) examination 1-8 times when they were in hospital or during the outpatient follow-up. Twenty children had imaging evidence for pneumonia, and 9 had patchy shadow mainly in the peripheral lung fields. Three (15.0%, 3/20) children were asymptomatic and did not have imaging finding during the first week in hospital, but had patchy shadow or unilateral ground-glass opacity by chest CT when rechecked before being discharged (3 patients) or after being discharged (1 patient). Unilateral pneumonia were found by CT in 3 children whose chest X-rays were normal. The history of illness and the time when imaging change occurred in 20 patients with SARS-CoV-2 pneumonia are shown in Table 3 . All children were treated in isolation, and stayed in designated hospitals for recruiting COVID-19 patients. Only seven (16.3%, 7/43) of the children were hospitalized in the infectious disease ward in the children's hospital or in pediatric ward in general hospitals. Thirty-eight children (88.4%, 38/43) received antiviral treatment, including 21 with monotherapy, 17 with two or more than two antiviral drugs (Table 4 ), The duration of antiviral treatment ranged from 5 to 31 days with a mean as 14.9 (SD: 7.4) days. Five patients were not prescribed with any antiviral drugs. No patient was Accepted Article administered with corticosteroidor intravenous immunoglobulin. Oral Chinese medicine was used in 20 cases for 2-35 days. By March 6, 2020, all of the 43 children were discharged with favorable outcome. Their hospital stay ranged from 3 to 32 days with a mean of 20.2 (SD: 7.9) days. Criteria for discharge were based on viral clearance in respiratory samples from upper respiratory tract, improvement of clinical symptoms and chest radiographic evidence. Eighteen children (51.4%, 18/35) had positive results of SARS-CoV-2 RT-PCR in feces when they were discharged. Alanine aminotransferase increased from normal to 106 U/L in one child after he was discharged and had received more than 30 days of oral Chinese medicine (He had had liver function abnormality after receiving antiviral treatment in hospital and had recovered when being discharged). All children were kept in quarantine for another 2 weeks, which included arrangement at resorts by the government for 35 and home quarantine for the other eight patients. By the end of April 20, 41 were followed up by telephone for at least twice, and one patient still had positive fecal RT-PCR results. On day 7 and day 14 after being discharged, the results of fecal RT-PCR switched to negative in 17.6% (3/17) and 33.3% (6/18) of the children, respectively. Positive fecal viral excretions were confirmed by RT-PCR for more than 70 days in one child since illness onset (As of April 20, 2020, follow up are going on). Fig2 shows the clearance curves of SARS-cov-2 in feces in cases treated with different antiviral regiments. None of their family contacts developed new infection during the quarantine periods. Imaging evidence for pneumonia was found in 1 child (he was asymptomatic at that time) when he was re-checked by CT 7 days after being discharged. This article is protected by copyright. All rights reserved. Currently, a few studies on pediatric SARS-CoV-2 infection were reported accompanied by the global pandemic of COVID-19 in the world, though the numbers of cases included in these studies were usually small because of the low incidence in children. Xu et al 7 studied 745 children and 3,174 adults who had either close contact with diagnosed patients or had family clusters and found that positive rate in adults was 2.7-fold higher than that in children. Similarly, in the present study, we investigated all of the contacts in the same families and found that the incidence of SARS-CoV-2 infection in children contacts was 13.2%, which was much lower than that in adults receptors-ACE2 and TMPRSS2 in the upper and lower airways than that of adults 15 , and the reduced airway tissue expression of ACE2 and TMPRSS2 may be the reason why children had lower risk of infection 16, 17 . With the implementation of policy to restrict the movement of people, the epidemic trend of COVID-19 in children was controlled much better than that in adults, and no new cases were confirmed since February 10, 2020, which may be due to the low susceptibility, as well as the reduced exposure. Most of the children were at school ages and were in family clusters. The epidemic peak in children was two weeks later than that in adults, which might be associated with the longer incubation stage 7, 18 . The median incubation period in adults usually was 3.0-6.4 days 2-6, 19 . Conversely, it was much longer in children 7 . The median incubation period was 9.1 Accepted Article patients when pneumonic images were found by chest CT or X-ray, indicating that change in pulmonary image might be later than the appearance of clinical symptom. The possible progress of SARS-CoV-2, an emerging virus, in children was not clear, which might lead to the over examination by chest CT. Chest CT helps to find more cases with COVID-19 from children with mild symptoms or even without any symptoms 21 . Even so, when we look back on these children with SARS-CoV-2 infection, we question the necessity of chest CT in most cases with mild symptoms or even without any symptoms. As previously mentioned, COVID-19 is an emerging disease and little was known about it in children when it broke out. Thus, an effective treatment has not been established. Symptoms in adults were severer, and antiviral drugs, such as oral lopinavir/ritonavir, oral arbidol and atomization inhalation with interferon, were widely used in adults in Zhejiang province. Accordingly, pediatric cases, including asymptomatic children, most of which were hospitalized in infectious disease ward in general hospitals, were given antiviral drugs. It was difficult to analyze the effectiveness of antiviral therapy in children by the duration it needed to improve clinical symptoms, because their symptoms were mild and transient. As an alternative, we evaluated the outcome of treatment by analyzing the persistent respiratory and fecal viral shedding, and found that there was no difference among the groups received no antiviral therapy, or received one, two, three or more than three antiviral drugs. Furthermore, gastrointestinal reactions and liver function abnormality occurred in some children after receiving≥3 antiviral drugs. Given that no antiviral treatment for coronavirus infection has been proven to be effective, we advise that, antiviral treatment might not be necessary for COVID-19 children without severe symptoms 22 . The best Accepted Article way to treat pediatric mild SARS-CoV-2 infection might be doing nothing except close monitoring and isolation. In this study, 18 children were discharged with positive results of fecal SARS-CoV-2 RNA detection. All of them were quarantined for another 2-4 weeks at resorts or at home. No new patient was found among their family members with close contact. According to previous studies, no evidence of fecal-oral transmission has been found for respiratory virus, the human coronavirus SARS or MERS. Similarly, there is no conclusive evidence that SARS-CoV-2 can cause illness by ingesting contaminated food or water to date. Therefore, we believe that a negative result of SARS-CoV-2 RNA detection in feces is not necessary for patients, whose clinical signs and symptoms had disappeared, to be discharged or released from isolation 23 . The level of expression of the viral receptor (ACE2) and TMPRSS2, especially in the nasal tissue, may be critical for the ability of the virus to transmit and replicate. The reason for prolonged viral shedding in feces in children is unknown yet. As the receptor of SARS-CoV-2, ACE2, was abundantly expressed in gastric, duodenal and rectal epithelia in COVID-19 patients 24 , which may lead to virus internalization and accumulation in these organs. It might explain the prolonged fecal virus shedding but needs to be further investigated. In the present study, there were two neonates delivered by mothers with COVID-19, fortunately, neither clinical nor laboratory evidence for SARS-CoV-2 infection was confirmed in these babies. Till now, no case with vertical transmission was identified among pregnant women infected with SARS-CoV or MERS-CoV 25 . However, during the epidemic of COVID-19 in China, a neonate, Accepted Article delivered by a SARS-CoV-2 infected pregnant woman in Wuhan, was confirmed with COVID-19 at the age of 30-hour-old. The baby had shortness of breath together with abnormal chest imaging and liver function abnormalities 26 . The possible route of SARS-CoV-2 transmission between the mother and neonate was not conclusive 25 . Our study has some limitations. First, the size of the cases was small, and all of the 43 children with SARS-CoV-2 infection were hospitalized in 15 local designated hospitals according to the principle of localization management, the program for pediatric cases was not run across hospitals. The diagnosis was confirmed with respiratory tract specimens and paired rectal swabs or feces specimens were not obtained for all children. The interval time of SARS-CoV-2 RNA detection was also variable. Therefore the durations of viral excretion through the gastrointestinal and respiratory tracts were not accurate. Second, not all children in the family with infected members were checked by real-time RT-PCR for SARS-CoV-2 RNA. Adolescent was not separated from the adult group because of the small sample size. Finally, the finding that antiviral therapy did not affect viral shedding outcomes was evaluated observationally，further study based on clinical trials of antiviral therapies is needed. In conclusion, we found that susceptibility of SARS-CoV-2 infection in children was lower, and the incubation periods were longer than that in adults. The clinical symptoms in pediatric cases were mild. Chest CT or X-ray is helpful for diagnosing SARS-CoV-2 pneumonia; however, the necessity is questionable because most patients had mild symptoms and would be self-healing. Benefit of antiviral treatment on improving the clinical signs or shortening the duration of potential Accepted Article Fig 2 The clearance curves of SARS-cov-2 in feces in cases treated with different antiviral regiments Imaging finding 16 20 Bilateral involvement 3 4 Unilateral involvement 13 16 Bilateral or unilateral ground-glass opacity 7 9 Leucocytes <4×10 9 /L (n) 4 5 lymphocytes <1.2×10 9 /L (n) 1 3 Note: *Alanine aminotransferase, ALT 54-112 U/L, Aspartate aminotransferase, AST 57-124 U/L This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved. Coronavirus disease (COVID-19) Situation Report -142 A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster Coronavirus Investigating, and Research Team. A novel coronavirus from patients with pneumonia in China Clinical features of patients infected with 2019 novel coronavirus in Wuhan Expression of SARS-CoV-2 receptor, ACE2, and TMPRSS2 in the lung airways is lower in children compared to adults and increases due to smoking and COPD The characteristics of household transmission of COVID-19 Changes in contact patterns shape the dynamics of the COVID-19 outbreak in China A Case Series of children with 2019 novel coronavirus infection: clinical and epidemiological features Incubation period of 2019 novel coronavirus (2019-nCoV) infections among travellers from Wuhan, China Correlation of Chest CT and RT-PCR Testing in Coronavirus Disease 2019 (COVID-19) in China: A Report of 1014 Cases The role of CT in case ascertainment and management of COVID-19 pneumonia in the UK: insights from high-incidence regions Diagnosis and treatment recommendations for pediatric respiratory infection caused by the 2019 novel coronavirus Chinese baby tests positive for coronavirus 30 hours after birth Evidence for gastrointestinal infection of SARS-CoV-2 Prolonged presence of SARS-CoV-2 viral RNA in faecal samples Potential maternal and infant outcomes from coronavirus 2019-nCoV (SARS-CoV-2) infecting pregnant women: lessons from SARS, MERS, and other human coronavirus infections