Coronavirus and the GI system: What does the evidence tell us?
The coronavirus continues to have an enormous impact on the way we live. Over the past several months, we have begun to learn more and more about the virus. We’ve learned about how it spreads, its symptoms, how to detect it, and potential approaches for vaccines. Crucially, the virus has several documented impacts and features related to the gastrointestinal system. Let’s take a look at the evidence.
Note: As the medical and public health understanding of the coronavirus continues to evolve, there’s a lot we still don’t know for certain. It’s important to recognize the difference between evidence-based conclusions, emerging evidence without sufficient peer review, and speculation. We will carefully frame each point based on the amount and kinds of evidence supporting it.
Coronavirus Symptoms Associated with the Gastrointestinal System
The coronavirus can cause a range of symptoms, from a fever to a loss of smell and a headache. We do know that it can cause gastrointestinal symptoms in some cases. These well-documented GI symptoms include loss of appetite, nausea, vomiting, and diarrhea. However, not everyone with coronavirus will experience these symptoms.
Some interesting emerging research suggests that there may be clusters of symptoms. One of these clusters involves gastrointestinal symptoms. Researchers at King’s College London studied data from around 1,600 COVID-19 patients who logged their symptoms to the research group’s COVID Symptom Study app in March and April. They found six distinct clusters of symptoms from the data:
- Flu-like with no fever. Headache, loss of smell, muscle pains, cough, sore throat, chest pain, no fever.
- Flu-like with fever. Headache, loss of smell, cough, sore throat, hoarseness, fever, loss of appetite.
- Gastrointestinal. Headache, loss of smell, loss of appetite, diarrhea, sore throat, chest pain, no cough.
- Severe level one, fatigue. Headache, loss of smell, cough, fever, hoarseness, chest pain, fatigue.
- Severe level two, confusion. Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain.
- Severe level three, abdominal and respiratory. Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain, shortness of breath, diarrhea, abdominal pain.
As you can see, the gastrointestinal cluster includes GI symptoms like diarrhea and loss of appetite. Other clusters also contain GI symptoms. Each cluster was also associated with differing proportions of patients who required hospitalization and breathing support. The escalating severe clusters had the largest percentage of patients requiring significant medical support.
It’s important to note that while the researchers have replicated their findings with a second 1,000 person data set from June, the research is not peer-reviewed yet. However, this is certainly something to keep an eye on as more data trends emerge.
Sewage: A Potential Method for Measuring Infection Spread
Early on in the pandemic, evidence emerged from multiple studies showing that people infected with the coronavirus shed viral particles in their poop. Whether the disease can spread through feces is still undetermined. However, there has been growing interest in sampling sewage to determine the extent of disease spread.
This has been particularly appealing because of the lack of adequate testing in many countries. This has led to a significant undercounting of actual infection numbers. A cross-sectional CDC study conducted across multiple states used serological testing on a convenience sample with people of all ages to identify how many had developed antibodies to the disease. This gave a more accurate picture of how many people have been infected, since the presence of antibodies indicates that a person had been or was currently infected. The study found that actual infection numbers were likely 10 to 12 times higher than reported through testing. Note that large-scale seroprevalence studies like this one are continuing to be conducted to identify likely infection rates, so the results here are preliminary.
With such a disparity between reported and actual case counts, wastewater sampling offers a convenient and accessible way to identify disease spread in a particular area. Importantly, results are quicker than those from viral and serological tests. This is helpful, timely data that can inform decisions about disease containment in the event of a flare-up. Additionally, it can help researchers see the viral ancestry of the disease, tracking different strains, viral changes over time, and spreading patterns and paths.
There are drawbacks, though. This kind of sampling can’t prove that an entire population is completely clear of the virus. Another drawback is that we still don’t know how many copies of viral RNA need to be present in a sample for disease to be detected. This means false negatives are possible, as we don’t know the minimum number of copies that trigger detection. A lower count of copies could go undetected with an improper assumption about a minimum.
Overall, there’s certainly a lot we still have to learn about the coronavirus and the GI system. However, as scientists conduct more and more research, we have a better opportunity to make data-informed decisions at public health, medical, governmental, interpersonal, organizational, and individual levels.
Our experienced team at GHP has years of experience helping patients with a variety of diseases and conditions. We can help establish the best plan of care for your situation. Contact any of our office locations to learn about the options we offer and schedule an appointment today.
