Since the end of 2019, the novel coronavirus (COVID-19) has spread to almost every corner of the world, infecting approximately 5 million people and causing over 332 thousand deaths globally (till 22nd May 2020). The viral infection mainly causes a series of respiratory illness. How the new virus affects the liver is unclear. As a gastroenterologist, I am keen to study the relationship between the virus with our digestive system or gastro-intestinal system.
The COVID-19 virus is believed to spread mainly from person-to-person through respiratory droplets produced when an infected patient coughs, or when in close contact with one another (within one meter). There are some clinical evidences indicate the gastrointestinal system could be an alternative route of COVID-19 infection besides the respiratory tract. However, according to the current available published data, the majority of the patients with COVID-19 still present with fever and respiratory symptom.
According to a China study1that involves 1099 patients with laboratory-confirmed COVID-19, nausea or vomiting, or both, and diarrhea were reported in 5·6% and 3·8% patients respectively. Opposing this finding, the Wuhan Medical Treatment Expert Group for COVID-192had reported that, half of their 204 patients diagnosed with COVID-19 reported gastrointestinal symptoms as main complaint. Patients with digestive symptoms had a significantly longer time from onset to admission than those without digestive symptoms (9.0 days vs. 7.3 days). Among those with digestive symptoms, 83.8% had lost of appetite, 29.3% had diarrhea, 0.8% had vomiting, and 0.4% had abdominal pain. Surprisingly, there were 7 patients presented with digestive symptoms, with otherwise no respiratory symptoms.
Europe and United States have emerged as the epicenters of the coronavirus pandemic. The physicians from these regions are worried of the implications of COVID-19 for patients with certain gastro-intestinal disease especially inflammatory bowel disease (IBD):
the risk of infection in patients with IBD?
what precautions to take, particularly for those who are on immunosuppressive treatment?
There are many convincing evidences showed that the comorbidity and mortality of COVID-19 in the patients with comorbidities are higher than those without comorbidities. Coronavirus uses ACE2 (Angiotensin-converting enzyme 2) is proven to be a viral receptor for entry process3. ACE2 mRNA is highly expressed and stabilized by B0AT1 in gastrointestinal system especially in the terminal ileum and colon, providing a prerequisite for COVID-19 infection. Dr. Xiao’s team had examined the stool viral RNA from 71 patients with COVID-19 hospitalized at their institution in February 20204. They found that 53.4% of patients had SARS-CoV-2 RNA in their stool and 23.9% of patients tested positive in their stool despite negative virus test in respiratory samples. The team also noticed that some patients with COVID-19 had mild to moderate liver injury as well. Till now, we didn’t see any evidence suggesting that COVID-19 occurs more common in patients with IBD. Those receiving biologic agents ought to be carefully monitored of the occurrence of symptoms and signs of COVID-19.
On 21stMarch 2020, Malaysian Society of Gastroenterology and Hepatology (MSGH) advised its members to:
1) Reduce or postpone non-urgent endoscopy cases.
2) Apply full personal protection equipment (PPE) when performing cases with patients with confirmed or high risk of COVID-19, ideally in a negative pressured room.
3) Practice a high standard of personal hygiene by:
a. wearing a surgical mask
b. frequent hand washing
c. practicing social distancing, and
d. avoiding crowded places.
Learning more about the relationship of COVID-19 with gastrointestinal manifestation is important as this may help with earlier diagnosis of COVID-19, earlier quarantine, faster approach to treatment or management, and lower unnecessary exposure. More data are required to further evaluate the effect of COVID-19 on our gastrointestinal system.
References
1.W. Guan, Z. Ni, Yu Hu, et. al, for the China Medical Treatment Expert Group for Covid-19. Clinical Characteristics of Coronavirus Disease 2019 in China. The new England journal of medicine.
2.Pan L, et al., Clinical characteristics of COVID-19 patients with digestive symptoms in Hubei, China: a descriptive, cross-sectional, multicenter study, Am J Gastroenterol
3.Li, W. et al. Angiotensin-converting enzyme 2 is a functional receptor for the SARS coronavirus. Nature 426, 450–454 (2003).
4.Xiao F, Tang M, Zheng X, Liu Y, Li X, Shan H, Evidence for gastrointestinal infection of SARS-CoV-2, Gastroenterology (2020)
By Dr Chieng Jin Yu, Medical Lecturer, Consultant Gastroenterologist and Hepatologist, Universiti Putra Malaysia (UPM).
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