COVID-19 and the gastrointestinal tract: what do we already know?

ABSTRACT The new coronavirus disease pandemic is defining 2020, with almost 17.5 million infected individuals and 700 thousand deaths up to beginning of August. It is caused by SARS-CoV-2 and the transmission is through the respiratory tract. Those infected may be asymptomatic, present typical symptoms (fever, dry cough and dyspnea), gastrointestinal symptoms (diarrhea, nausea, vomiting and abdominal pain) and viral RNA in stools. The objective of this work was to review the literature related to the prevalence of gastrointestinal symptoms, and to check the possibility of fecal-oral transmission. We searched PubMed® database on COVID-19 and gastrointestinal tract and selected articles using the PRISMA method. We eliminated articles based on titles and abstracts, small number of patients and the mechanism of infection, leaving 14 studies. Comorbidities and laboratory alterations (elevation of hepatic aminotransferases and bilirubin) were related to worsening of the disease. The prevalence of gastrointestinal symptoms ranged from 6.8% to 61.3%, including diarrhea (8.14% to 33.7%), nausea/vomiting (1.53% to 26.4%), anorexia (12.1% to 40.0%) and abdominal pain (0% to 14.5%). The presence of viral RNA in stools was rarely tested, but positive in 0% to 48.1%. The gastrointestinal tract is affected by COVID-19, causing specific symptoms, laboratory alterations and viral presence in the feces. However, the results of prevalence and possibility of fecal-oral transmission were varied, requiring further studies for more assertive conclusions. It is important that healthcare professionals draw attention to this fact, since these changes can help make diagnosis and initiate early treatment.

摘要 新型冠状病毒病（COVID-19）大流行重塑了2020年的全球公共卫生图景，截至8月初，全球累计报告近1750万例感染者、70万例死亡病例。该病由严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）引起，主要经呼吸道传播。感染者可表现为无症状感染，或出现典型症状（发热、干咳、呼吸困难），亦可出现胃肠道症状（腹泻、恶心、呕吐、腹痛），且粪便中可检测到病毒核糖核酸（RNA）。
本研究旨在综述与COVID-19胃肠道症状患病率相关的文献，并探讨粪口传播（fecal-oral transmission）的可能性。我们检索了PubMed®数据库中关于COVID-19与胃肠道的相关文献，并采用PRISMA方法进行文献筛选。通过排除标题与摘要不符、样本量过小以及聚焦于感染机制的文献，最终纳入14项研究。
研究显示，合并症与实验室指标异常（肝氨基转移酶及胆红素升高）与疾病病情恶化显著相关。胃肠道症状的患病率介于6.8%至61.3%之间，其中腹泻患病率为8.14%至33.7%，恶心/呕吐为1.53%至26.4%，食欲减退为12.1%至40.0%，腹痛为0%至14.5%。粪便病毒RNA的检测开展较少，但阳性率介于0%至48.1%之间。
胃肠道可受累于COVID-19，引发特异性临床症状、实验室指标异常及粪便病毒检出。然而，现有研究在胃肠道症状患病率及粪口传播可能性方面结果存在异质性，需开展更多研究以得出更具确定性的结论。医护人员需关注这一现象，因其可为疾病诊断与早期治疗提供参考依据。