Coronavirus Infects Our Intestines and Can Damage the Heart, Report Says

Rectal swabs show virus persistence long after our nasopharyngeal systems are clear, studies show

Send in e-mailSend in e-mail
Illustration of a villus in the intestine with a zoom-in to an electron microscopy image of coronavirus SARS-CoV-2 (dark circles) at the edge of an intestinal cell.
Illustration of a villus in the intestine with a zoom-in to an electron microscopy image of coronavirus SARS-CoV-2 (dark circles) at the edge of an intestinal cell.Credit: Kvin Knoops / Raimond Ravell

The coronavirus can infect cells of the intestine and multiply there, says a team of Dutch researchers based on laboratory studies of cells in petri dishes, which indicates that intestinal issuance can potentially transmit infection. They also demonstrated that the virus, SARS-CoV-2, can multiply using intestinal cells, which strongly indicates the possibility of “fecal-oral” transmission.

Meanwhile, separate studies have shown that the coronavirus can also damage the heart. In some patients, the initial symptoms didn’t even necessarily involve labored breathing but cardiovascular problems.

Fecal-oral transmission is exactly what you think it is, and is generally caused by inadequate hygiene, not necessarily anilingus or coprophilia. Fecal germs of any kind can get transmitted to the mouth by “the five Fs” – fingers, fields, fluids, flies, and food. Fields can be watered with sewage, for instance, and the “flies” refers to any garbage-oriented aviating arthropod.

Previous studies had identified genetic material from the new coronavirus in stool, but had fallen short of demonstrating that the viral particles in feces were infectious. Now, by culturing human intestine cells in the lab, the researchers show that the virus can propagate in the cell culture, as they reported in Science (a publication of the American Association for the Advancement of Science).

SARS-CoV-2, which causes COVID-19, is an RNA virus, meaning its genetic material is a strand of RNA, not DNA. That RNA contains the genetic code for a number of proteins, including the one it uses to “dock” onto specific human cells that have a specific protein called ACE-2 on their exterior. When a virus locks onto a cell’s ACE-2, that triggers the target cell’s membrane to “swallow” the virus. Once inside the cell, the virus hijacks the cell’s mechanisms to produce more viral particles – the progeny. Eventually, the cell explodes from all the progeny inside, scattering the new viruses into our systems to infect more cells.

Intestinal organoids, the right one infected with coronavirus SARS-CoV-2. The coronavirus is colored white, the organoids themselves are colored blue and green.Credit: Joep Beumer / copyright Hubrecht

The chief entry point for SARS-CoV-2 is our pulmonary system, the cells of which copiously express ACE-2. We can catch the coronavirus through our nose and mouth, and our eyes too. But the next question is where in our bodies the virus can infect and proliferate. Or, to put it another way: which cellular systems express that “docking protein” ACE-2.

The list of systems with ACE-2 turn out to include the pulmonary system, certain tissues in the kidneys, and the testicles, though not the ovaries – which may explain why the disease is deadlier for men than women. And, ACE-2 is also copiously expressed by our intestinal tissues.

This in turn means that we can potentially infect a virologically naive person (or ferret) by sneezing or coughing on them, spitting at them, breathing hard in their direction within a reasonable distance – or through our intestinal issuance.

What’s more, it turns out that the testicles and our guts may continue to harbor the coronavirus after our nasopharyngeal systems sound the all-clear. “Viral RNA can be found in rectal swabs, even after nasopharyngeal testing has turned negative, implying gastrointestinal infection and a fecal-oral transmission route," the researchers say.

Their findings could explain why about a third of COVID-19 patients report gastrointestinal symptoms such as diarrhea and discomfort, and the fact that the virus often can be detected in stool samples.

The viral particles don’t “survive” outside the body for long, and most of us don’t handle each other’s fresh feces. But it does beg the question – raised initially by Australian doctors – of whether flatulence can infect. It hasn’t been proved and farts definitely aren’t the cause of the massive spread of the coronavirus, but it can’t be ruled out yet.

To wrap this up: the presence of viral particles in raw sewage is already being used to gauge the spread in some areas without mass testing. Can you get the coronavirus from sewage? Almost certainly, but that isn’t the chief mechanism of infection – again at the least because most people don’t come into contact with other people’s raw waste. There have not been cases of water treatment staff becoming ill that way either, insofar as is known.

Intestinal tissue in the lab infected with coronavirus SARS-CoV-2. The coronavirus is colored white, the organoids themselves are colored blue and green.Credit: Joep Beumer / copyright Hubrecht

Can you get the coronavirus from drinking water? Not if the water has been treated. Can you get it from a water body – pools, for instance? Again, those generally use treated water. The best advice remains to meticulously maintain social distancing, use a mask – especially if you think you might be infectious or have been exposed to the virus – and to wear not only a mask when in society but also pants.

As for the damage the virus causes to the heart, as Johns Hopkins medical center explains, that is highly patient-specific but it isn’t due to direct infection.

“Heart failure has been the cause of death in COVID-19 patients, even those without severe breathing problems such as acute respiratory distress syndrome, or ARDS,” writes Dr. Erin Michos. Why does the heart fail? Could be any of a number of reasons, but they boil down to the extra stress that the coronavirus causes the body – including by massive stimulation of our own immune systems. Michos points out that flu may do that, too.

Comments