Residual SARS-CoV-2 viral antigens detected in gastrointestinal and hepatic tissues from two recovered COVID-19 patients

Cheung, Chun Chau Lawrence; Goh, Denise; Lim, Xinru; Tien, Tracy Zhijun; Lim, Jeffrey Chun Tatt; Nerurkar, Sanjna Nilesh; Loong, Shihleone; Cheow, Peng Chung; Chan, Chung Yip; Koh, Ye Xin; Tan, Thuan Tong; Kalimuddin, Shirin; Tai, Wai Meng David; Ng, Jia Lin; Low, Jenny Guek Hong; Yeong, Joe; Lim, Tony Kiat Hon

Residual SARS-CoV-2 RNA has been detected in stool samples and gastrointestinal tissues during the convalescence phase of COVID-19 infection. This raises concern for persistence of SARS-CoV-2 virus particles and faecal-oral transmissibility in recovered COVID-19 patients. Using multiplex immunohistochemistry, we unexpectedly detected SARS-CoV-2 viral antigens in intestinal and liver tissues, in surgical samples obtained from two patients who recovered from COVID-19. We further validated the presence of virus by RT-PCR and flow cytometry to detect SARS-CoV-2-specific immunity in the tissues. These findings might have important implications in terms of disease management and public health policy regarding transmission of COVID-19 via faecal-oral and iatrogenic routes during the convalescence phase.