Severe acute respiratory syndrome associated coronavirus is detected in intestinal tissues of fatal cases

OBJECTIVES: A significant percentage of confirmed severe acute respiratory syndrome (SARS) patients experienced gastrointestinal symptoms, and the viral sequence was detectable in the stool of most patients. At present, the knowledge of the pathology of the digestive system in SARS patients is limited. Because a resurgence of the SARS epidemic is constantly possible, there is an urgent need to understand the involvement of the digestive system in this new disease. METHODS: We performed seven SARS autopsies in which samples of alimentary tract and digestive glands were examined with routine pathology, electron microscopy (EM), in situ hybridization (ISH), immunohistochemistry, and real-time polymerase chain reaction (PCR). RESULTS: The main histopathological finding was atrophy of the mucosal lymphoid tissue. A few mucosal epithelial cells and lymphocytes in the intestine were positively stained for coronavirus with ISH. SARS-coronavirus (CoV)-like particles were found in the mucosal epithelial cells under EM and mild focal inflammation was detected in the alimentary tract. One patient who experienced severe diarrhea had pseudomembranous enteritis of the ileum. Fatty degeneration and central lobular necrosis were observed in the liver. No evidence of direct viral infection was found in the esophagus, the stomach, the salivary gland, the liver, or the pancreas. CONCLUSIONS: In addition to the lungs, the gastrointestinal tract is another target of SARS-CoV infection, as the intestinal epithelial cells and mucosal lymphoid tissue are infected. The findings provide possible explanations for the gastrointestinal symptoms and the presence of virus in the stool of SARS patients.