Growing evidence suggests the coronavirus can spread through poop. Here's how to protect yourself.

  • The new coronavirus is primarily a respiratory illness, and it typically spreads via airborne particles from an infected patient's coughs or sneezes.

  • Some research suggests the virus can also spread via fecal matter. Multiple studies have found traces of the virus in infected patients' poop.

  • SARS, another coronavirus, also spread through poop.

  • Here's what you can do to protect yourself.

  • Visit Business Insider's homepage for more stories.

To lower your risk of catching the new coronavirus, health authorities recommend staying 6 feet from individuals who show any signs of illness. That's because the coronavirus typically spreads via airborne particles when an infected person coughs or sneezes. Those viral particles can then infect someone after they land on their nose or mouth or get inhaled.

coronavirus bathroom
A member of the medical team sprays disinfectant to sanitize bathrooms in Imam Reza's holy shrine, following the coronavirus outbreak, in Mashhad, Iran on February 27, 2020.

WANA (West Asia News Agency) via Reuters

But a growing body of research suggests the coronavirus can also spread via poop particles.

A study of three coronavirus patients in Singapore, published Wednesday in the Journal of the American Medical Association, revealed that the virus showed up in their stool. Samples taken from the toilet bowls and sinks in the patients' isolation rooms came back positive for the virus.

New York City face masks coronavirus March 3 2020 Getty Images
People wear face masks on their way to the 7 train in New York City on March 3, 2020.

Tayfun Coskun/Anadolu Agency via Getty Images

That evidence supports findings from researchers at the Chinese Center for Disease Control and Prevention, who also detected viable virus particles in coronavirus patients' feces.

China's National Health Commission has confirmed that the virus can spread through contaminated poop,  the South China Morning Post reported on Tuesday.

The fact that the virus can be passed through both our respiratory and digestive systems may explain how it spread from its origin city of Wuhan, China to more than 80 countries in just a few months, researchers suggest.

The virus can travel in poop particles

The authors of the Chinese CDC study wrote that "stool samples may contaminate hands, food, water, etc.," then cause infection if the particles enter a person's mouth, nose, or eyes. For example, an infected patient could use the bathroom, forget to wash their hands or give only a cursory rinse, then touch a friend's hand. That friend could then rub their face and get virus. In medicine, this is known as fecal-oral transmission.

"This virus has many routes of transmission, which can partially explain its strong transmission and fast transmission speed," the study authors wrote.

That research and the new case study from Singapore adds to a growing body of evidence we have about fecal-oral transmission risk. Here are three other pieces of evidence:

  • Researchers detected coronavirus RNA in poop from the first US patient — a man from Snohomish County in Washington state who was diagnosed in late January — according to a report in the New England Journal of Medicine.

  • Another January study, which has yet to be peer-reviewed, detected an enzyme signature of the virus in cells from coronavirus patients' small intestines and colons. Typically, coronavirus particles dock to cell receptors in our upper respiratory tract. But those same receptors live in our digestive system, and the study authors suggested that our intestines could be invaded too.

  • Blood and anal swabs from nearly 140 coronavirus patients at a Wuhan hospital revealed traces of the virus as well.

coronavirus conference
Visitors pass a sign in Toronto, Canada, warning about the spread of germs, after another case of COVID-19 was confirmed in the city, March 1, 2020.

Chris Helgren/Reuters

Other coronaviruses — like those that infect horses and cats — frequently spread via poop. If a healthy horse eats a piece of hay contaminated with fecal matter from an infected horse, for example, it can get sick. Researchers think the new coronavirus jumped from bats to another animal before infecting humans. That initial spread from bats likely happened via poop, too.

How to protect yourself

The Chinese CDC said the possibility of fecal-oral transmission further underscores the importance of frequent hand washing and the need to disinfect objects and surfaces in medical facilities, transportation vehicles, public toilets, and homes.

coronavirus store
A worker wearing protective gear sprays disinfectant as a precaution against the new coronavirus at a department store in Seoul, South Korea, March 2, 2020.

AP Photo/Lee Jin-man

Other viruses like Hepatitis A and Hepatitis E also spread via fecal-oral transmission. Such viruses can use "a vehicle such as food, water, or utensil, and enter a new host through the mouth," according to the US CDC.

Accordingly, careful food-handling and washing is also important. Both the US and Chinese CDCs recommend boiling drinking water if there's a possibility it could be contaminated with sewage, and not eating raw food like shellfish or produce that may have been harvested or washed in contaminated water.

Avoiding swimming pools that may contain contaminated water is also important.

SARS spread through poop, too

During the 2002-2003 SARS outbreak (SARS is also a coronavirus), researchers documented an instance in which one sick person had diarrhea in a Hong Kong apartment building, and the virus then traveled through the pipes to infect other residents.

In that instance, an issue with the drainage pipes caused a situation in which running exhaust fans with the bathroom door closed created enough negative pressure to suck fecal droplets out of the sewage system and into the bathroom. Those virus-laden droplets then landed on floor mats, towels, and toiletries that residents touched.

Flight attendant cleans dirty airplane disinfectant
A flight attendant sprays disinfectant onboard a Thai Airlines flight to Chiang Mai from Bangkok during the 2003 SARS outbreak.

Paula Bronstein / Getty Images

Up to 76% of SARS patients experienced diarrhea. The symptom has also cropped up among a minority of patients with the new coronavirus: The first US patient had diarrhea the day after he arrived at the hospital. Coronavirus patients in Vietnam have also reported diarrhea as a symptom, and a non-peer-reviewed study of 1,099 Chinese patients found that 4% had diarrhea, too.

But a person with the new coronavirus doesn't need to have an upset stomach to shed the virus in their poop. One of the patients from the Singapore case study had normal stool, but their poop still tested positive.

Morgan McFall-Johnsen contributed reporting to this story.

Read more about the new coronavirus:

Some coronavirus patients experience nausea, vomiting, or diarrhea before they get a fever. They could spread the virus through poop.

Workers at 6 US hospitals reveal how they respond to potential coronavirus cases — including face shields and negative-pressure isolation chambers

People are racing to buy face masks amid the coronavirus outbreak, but they probably won't protect you from illness

The outbreaks of both the Wuhan coronavirus and SARS likely started in Chinese wet markets. Photos show what the markets look like.

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