The occurrence of diarrhea in COVID-19 patients.

To the editor,

Corona Virus Disease 2019 (COVID-19) is currently affecting public health in many countries around the world, including China, Italy, Iran, Korea, France, and more than 100 other countries, and has been characterized as a pandemic [1]. Respiratory droplets and contact are the main routes of transmission of COVID-19 [2]. However, the fetal-oral routes may also be a potential human-to-human transmission [3], [4]. Admittedly, recent studies have reported the detection of the virus (SARS-COV-2) in feces [4], [5], [6]. SARS-COV-2 infects human cells through angiotensin-converting enzyme 2 (ACE2) [7], and the expression of ACE2 in the small intestine is significantly higher than that in the lung [8]. In theory, the intestine is the target organ for SARS-COV-2 infection. In fact, diarrhea as a bowel symptom is not rare in COVID-19 patients. Although the occurrence of diarrhea is not as high as that of fever and cough, it may be the first symptom of COVID-19. Here, we summarized the occurrence of diarrhea that are currently publicly available (Table 1 ). A total of 2506 COVID-19 patients were included, of which 145 had diarrhea before admission and the overall occurrence of diarrhea was 5.8% (145/2506). In our own data, the occurrence of diarrhea is 6.3% (4/64) (not yet published). Differential occurrence of diarrhea across studies may be due to different criteria for determining diarrhea. Another possible reason is that the patient's bowel movements were not listed as the focus of observation. In general, diarrhea is not a common symptom in patients with COVID-19. More attention is needed because diarrhea is a reminder that SARS-COV-2 invades the intestine. In autopsy reports of patients with COVID-19, staged narrowing and expansion of the small intestine may be a more intuitive warning [9]. Future research should focus on how long SARS-COV-2 persists in the feces of COVID-19 patients with diarrhea. This helps to better manage discharged patients and to properly dispose of the patients’ feces, thereby avoiding potential sources of SARS-COV-2. Clinicians, especially digestive physicians, should pay close attention to the atypical symptoms of COVID-19 and take personal protection against the feces of patients. When discharged from home, patients with COVID-19 should pay special attention to hand hygiene and avoid sharing toilets with family members. In addition, we remind the public not to panic, but to prevent it scientifically.

Table 1

The occurrence of diarrhea in the reported literature.

Literature	The located cities	Total cases, (n)	The occurrence of diarrhea, % (n)	Literature Doi
1	Wuhan	139	12.9% (18)	http://dx.doi/10.1111/all.14238
2	Wuhan	278	6.1% (17)	http://dx.doi/10.1016/j.ijantimicag.2020.105924
3	Guangzhou	90	6% (5)	http://dx.doi/10.1007/s00259-020-04735-9
4	More than 5 cities in Hubei Province	137	8% (11)	http://dx.doi/10.1097/CM9.0000000000000744
5	Beijing	13	7.7% (1)	http://dx.doi/10.1001/jama.2020.1623
6	More than 30 cities in China	1099	3.8% (42)	http://dx.doi/10.1056/NEJMoa2002032
7	Wuhan	38	3% (1)	http://dx.doi/10.1016/S0140-6736(20)30183-5
8	Wuhan	99	2% (2)	http://dx.doi/10.1016/S0140-6736(20)30211-7
9	Wuhan	138	10.1% (14)	http://dx.doi/10.1001/jama.2020.1585
10	More than 5 cities in Zhejiang Province	62	4.8% (3)	http://dx.doi/10.1136/bmj.m606
11	Nanjing	24	8.3% (2)	http://dx.doi/10.1007/s11427-020-1661-4
12	Wuhan	34	14.7% (5)	http://dx.doi/10.1016/j.tmaid.2020.101606
13	Guangzhou	90	6% (5)	http://dx.doi/10.1007/s00259-020-04735-9
14	Shenzhen	6	33% (2)	http://dx.doi/10.1016/S0140-6736(20)30154-9
15	Shanghai	51	10% (5)	http://dx.doi/10.1148/radiol.2020200274
16	Jinhua	14	0	http://dx.doi/10.1002/jmv.25742
17	Yancheng and Wuxi	80	1.3% (1)	http://dx.doi/10.1093/cid/ciaa199
18	Wuhan	5	0	http://dx.doi/10.1097/CM9.0000000000000722
19	Wuhan	43	16.3% (7)	http://dx.doi/10.1101/2020.02.23.20026864
20	Huai’an	66	6.3% (4)	Not yet published
Total		2506	5.8% (145)

Author contributions

Hong-Gang Wang and Xiao-Zhong Yang designed the research; Xiang-Yu Li, Wei-Jie Dai and Shang-Nong Wu collected the data; Xiang-Yu Li and Hong-Gang Wang wrote the paper.

Disclosure of interest

The authors declare that they have no competing interest.