SARS-CoV-2 may produce intestinal symptoms that are generally mild, with a small percentage of patients developing more severe symptoms. The involvement of SARS-CoV-2 in the physiopathology of bowel damage is poorly known. Transmission electron microscopy (TEM) is a useful tool that provides an understanding of SARS-CoV-2 invasiveness, replication and dissemination in body cells but information outside the respiratory tract is very limited. We report two cases of severe intestinal complications (intestinal lymphoma and ischaemic colitis) in which the presence of SARS-CoV-2 in intestinal tissue was confirmed by TEM. These are the first two cases reported in the literature of persistence of SARS-CoV-2 demonstrated by TEM in intestinal tissue after COVID 19 recovery and SARS-CoV-2 nasopharyngeal clearance. During the first pandemic peak (1st March–30th April 2020) 932 patients were admitted in Hospital Universitari Mútua Terrassa due to COVID-19, 41 (4.4%) required cross-sectional imaging techniques to assess severe abdominal pain and six of them (0.64%) required surgical resection. SARS-CoV-2 in bowel tissue was demonstrated by TEM in two of these patients. The first case presented as an ileocaecal inflammatory mass which turned to be a B-cell lymphoma. Viral particles were found in the cytoplasm of endothelial cells of damaged mucosa. In situ hybridization was negative in tumour cells, thus ruling out an oncogenic role for the virus. SARS-CoV-2 remained in intestinal tissue 6 months after nasopharyngeal clearance, suggesting latent infection. The second patient had a severe ischaemic colitis with perforation and SARS-CoV-2 was also identified in endothelial cells. Severe intestinal complications associated with COVID-19 are uncommon. SARS-CoV-2 was identified by TEM in two cases, suggesting a causal role in bowel damage.

中文翻译：

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通过透射电子显微镜在 COVID-19 急性腹痛患者的淋巴组织增生和缺血性肠道病变中鉴定出 SARS-CoV-2：两例报告

SARS-CoV-2 可能会产生一般轻微的肠道症状，一小部分患者会出现更严重的症状。SARS-CoV-2 参与肠道损伤的病理生理学知之甚少。透射电子显微镜 (TEM) 是一种有用的工具，可帮助了解 SARS-CoV-2 在体细胞中的侵袭、复制和传播，但呼吸道外的信息非常有限。我们报告了两例严重的肠道并发症（肠道淋巴瘤和缺血性结肠炎），其中经 TEM 证实肠道组织中存在 SARS-CoV-2。这是文献中报道的前两个病例，在 COVID 19 恢复和 SARS-CoV-2 鼻咽清除后，TEM 证明肠道组织中 SARS-CoV-2 持续存在。在第一个大流行高峰期间（2020 年 3 月 1 日至 4 月 30 日），932 名患者因 COVID-19 入院 Universitari Mútua Terrassa，其中 41 名（4.4%）需要横断面成像技术来评估严重腹痛，其中 6 名（0.64 %) 需要手术切除。其中两名患者的 TEM 证实了肠道组织中存在 SARS-CoV-2。第一个病例表现为回盲部炎性肿块，后来变成 B 细胞淋巴瘤。在受损粘膜内皮细胞的细胞质中发现病毒颗粒。原位杂交在肿瘤细胞中呈阴性，因此排除了该病毒的致癌作用。鼻咽部清除后 6 个月，SARS-CoV-2 仍留在肠组织中，表明存在潜伏感染。第二名患者患有严重的缺血性结肠炎穿孔，在内皮细胞中也发现了 SARS-CoV-2。与 COVID-19 相关的严重肠道并发症并不常见。在两起病例中通过 TEM 鉴定出 SARS-CoV-2，表明其在肠道损伤中起因果作用。