A recent medical study of recovered Covid patients' stool samples has discovered that the coronavirus can remain in your gut for seven months - leading scientists to argue that the virus can survive for months in hidden viral "reservoirs".
Covid-negative patients with fragments of the virus in their faeces were more likely to report continued nausea, abdominal pain, and vomiting - even after their other symptoms had long faded.
The study involved 113 participants taking samples over the course of several months. Authors of the study suggest that their results indicate that COVID-19 infects the gut and that this infection continues for people who suffer from Long Covid.
While the vast majority of people recover from a Covid infection over the course of a few days or weeks, some people report experiencing continued symptoms or health problems months after testing positive. This has puzzled scientists who have struggled to explain why this is happening.
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The discovery that a small number of participants, 3.8 per cent, were still shedding coronavirus in their stool samples seven months after infection could indicate a source for this widespread phenomenon.
In the study, they found traces of Covid RNA in 85 per cent of the samples of those currently infected with the virus. After a week this fell to half and by four months only 12 per cent still had a positive stool sample.
“No one really knows what causes long COVID,” says study author Dr. Ami Bhatt, who is an associate professor of medicine and genetics for Stanford Medicine at Stanford.
“Maybe long COVID — and the wide variety of symptoms it causes — is due to the immune system’s response to viral proteins in hidden reservoirs throughout the body,” she added.
For example, she speculates that people with long COVID who experience cognitive symptoms, known as “brain fog,” could have a lingering SARS-CoV-2 infection in their nervous system - in the same manner as those with lingering stomach problems were more likely to continue shedding the virus through their faeces.
There are some challenges to these results. The study took samples and data from a larger piece of Stanford medical research, which asked participants to seal their samples in a bag that would deactivate the virus.
This means the scientists could only identify the dead fragments of the virus, so were unable to state categorically that the gut holds live coronavirus.
In answer to this, the authors of the study point to similar viruses to Covid being found in people's intestines during post-mortems, including a recent discovery of gastrointestinal covid in an autopsy.
What were all the symptoms identified in this study?
This study identified a wide range of different reported symptoms of Long Covid, that they believe could be linked to their study's findings. They are:
- Headache
- Runny nose
- Body ache
- Abdominal pain
- Nausea
- Vomiting
