With input from Dr Monica Vasudev

1282: COVID-19: Affinity for the Digestive System

1. February: presence of gastrointestinal (GI) symptoms was reported in the first case of COVID-19 in the U.S.
2. In the early days, the focus was on respiratory symptoms and transmission; however, researchers from China soon identified the GI/fecal/oral route as another avenue of spread for the SARS-CoV-2 virus.
3. The oral route acts as a point of entry into the body and the digestive tract is a primary organ system for the multiplication, replication, and potential spread of the virus, as per Brennan Spiegel, MD, of Cedars-Sinai Medical Center in Los Angeles.
4. Experts quickly cautioned that extra-pulmonary complications in the GI tract might be more common than previously thought and should not be missed in the differential diagnosis.
5. Also GI symptoms, which appeared to affect 5% to 15% of patients, often persisted after the acute phase of the infection and sometimes pointed to poorer outcomes.
6. Besides the February report, U.S. and Chinese researchers suggested that digestive symptoms were a possible hallmark of COVID-19 infection in some patients. Doctors were advised to assess all patients with GI complaints for the virus.
7. In March, increasing evidence of such symptoms in about 50% of patients prompted several U.S. GI societies to issue a message on clinical precautions for providers of endoscopy and other gastroenterology care.
8. Around the same time, a Chinese study showed that in a subgroup of COVID-19 patients with mild disease, digestive problems, such as nausea and diarrhea, might be the only symptoms, with no sign of fever or respiratory symptoms, and should, therefore, be part of the differential diagnosis.
9. Early May: Clinicians from New York revealed that 22% of hospital-assessed COVID-19 patients had diarrhea, 7% had abdominal pain, 16% had nausea, and 9% had vomiting. Overall, 33% of patients had at least one GI manifestation, and 62% of patients had biochemical evidence of liver injury.
10.    Chinese researchers showed that 50.5% of COVID-19 patients presenting at hospitals had at least one digestive tract symptom and among nearly half of these patients, a digestive problem was the chief complaint. GI involvement was associated with longer hospital stay and worse outcomes - only 34.3% of those with digestive symptoms recovered while 60% of patients without digestive symptoms were discharged as recovered.
11.   By July, Italian physicians reported that hospitalized patients had lingering symptoms, including troublesome GI manifestations, for up to 2 months after recovering from the acute phase.
12.   A California study linked the use of a proton pump inhibitor (PPI) to a heightened risk of COVID-19 positivity.
13.   August: Research revealed that the virus can present as acute idiopathic pancreatitis and Black and Hispanic patients with existing pancreatitis were more vulnerable to COVID-19.
14.   Fall: Chicago clinicians presenting at the 2020 American College of Gastroenterology (ACG) virtual meeting noted that GI symptoms at initial presentation had an independent association with poor prognosis. Diarrhea at presentation was associated with more severe disease and poor prognosis, suggested a review and meta-analysis also presented at the meeting.
15.   North American Alliance for the Study of Digestive Manifestation of COVID-19 suggested that while severe GI complications admitted to the ICU were uncommon (5.1%), they were tied to a death rate of 55.6%. While the study demonstrated a low incidence of intestinal ischemia, investigators cautioned that COVID-19 is a hypercoagulable disorder, associated with a higher incidence of venous thromboembolism.It can potentially infect the endothelial cells of different vascular beds in the heart, small bowel, and lungs. Therefore, endotheliitis caused by COVID-19 can result in microthrombus formation and organ ischemia.
16.   As per Brett Williams, MD, of Chicagos Rush University Medical Center, "We know this virus has a propensity to cause endotheliitis, which can obviously involve any organ. Patients with GI symptoms quite possibly have direct viral invasion of the GI mucosa, liver, and pancreas, though in sepsis-type syndromes,its difficult to know how much the inciting pathogen, hypoperfusion, and inflammation each contribute to pathology in any one organ system." He said that at his center, raised lipase levels in COVID-19 patients were relatively common, seen in 16.8% of those patients checked, and elevated lipase levels had a robust association with ICU admission and intubation. He added that receptors for the virus appear to be there in the pancreas, as well as in mature enterocytes.
17. December: A hospital study from New York revealed that 3% of COVID-19 inpatients had GI bleeding, which was associated with higher mortality.
18.   Most implicated in GI involvement are ACE 2 receptors which are in abundance in the intestines as well as the stomach and liver.
19.   Respiratory virus sheds into saliva from the shared upper airways and the salivary glands. Once swallowed, the viral-laden saliva passes through the acid layer making use of the ACE2 receptors to enter epithelial cells lining the intestine, where it undergoes replication. The gastric acid can inactivate most viruses. However, if the virus hits before the first meal of the day when the acid levels are low, or if one is taking a PPI or gets a large inoculum of virus, enough of it can get through to make it past.
20.   The long-haul effects of COVID-19, such as chronic diarrhea and nausea, can intensify pre-existing GI conditions, including irritable bowel syndrome (IBS) and other chronic problems.
21.  The virus can potentially disrupt the gut microbiome and exacerbate the mental anguish that these patients already feel.
22.   The virus may also trigger new-onset post-viral IBS.

[Medpage Today Excerpts]

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA