Fact check: We know about coughs and sneezes. But can coronavirus spread through farts?
The claim: Doctors say the coronavirus could be 'spreading across the globe' through passed gas
As health officials warn of the coronavirus spreading through droplets generated by sneezes and coughs, some people have wondered whether passed gas could also be a culprit of transmission. Recent articles, some shared widely on social media, have explored the possibility.
An April 11 article from the British tabloid Daily Star titled "Coronavirus 'could be spreading across the globe through farts' claim doctors" had 4,700 shares on Facebook as of Wednesday afternoon.
"Doctors have made the foul discovery that farting could spread the Covid-19 disease – unless infected people wear pants which can protect this from happening," the article's secondary headline reads.
The story cites an April 6 Twitter thread by Australian doctor Andy Tagg. It includes references to multiple studies based on observations China. One, from the U.S. Centers for Disease Control and Prevention's Emerging Infectious Diseases journal, describes how the virus was detected in the fecal matter of an asymptomatic child up to 17 days after exposure.
Another study, published in the Lancet, examined 98 COVID-19 patients and found 55% of the patients had fecal samples that tested positive for the virus, some of them for weeks.
As to whether there's potential that particles could be spread through passing gas, Tagg says there's not much science on the topic. He cited a medical experiment in which people passed gas into a petri dish, once with pants on and once without. The petri dish from the latter included gut flora, while the former did not.
"Perhaps SARS-CoV-2 can be spread thought the power of parping – we need more evidence. So remember to wear appropriate PPE at all times and stay safe!" he tweeted, alongside a photo of someone wearing large pants.
The Daily Star article goes on to say that the China’s Center for Disease Control and Prevention announced earlier this year that pants are an effective barrier against spreading the novel coronavirus through passed gas.
Can gas actually spread the virus? So far, there's no evidence that it's happening
While scientists are still researching the spread of COVID-19, health experts believe the novel coronavirus mainly spreads when an infected person coughs or sneezes, releasing respiratory droplets into the air, according to the CDC. Those droplets can then end up in the mouths or noses of nearby people, and spread is most likely within a 6-foot radius.
It's also possible that people can catch the virus by touching a surface with the virus on it, then touching their faces. For those reasons, medical professionals have recommended frequent handwashing and social distancing to combat the virus' spread.
Dr. William Schaffner, medical director of the National Foundation for Infectious Diseases and infectious diseases professor at Vanderbilt University, said at this point, transmission of coronavirus through passed gas has "never been demonstrated."
"It becomes a highly theoretical exercise to discuss it," he said. "It's very unlikely."
On a microscopic level, it's true that fecal matter can be found in passed gas, he said. As studies like those cited by Tagg indicated, scientists have detected viral remnants in feces, although Schaffner said it's still unclear whether the virus can be spread in that way.
The CDC's website confirms that while the coronavirus has been found in fecal matter of some of those infected, there has been "no confirmed fecal-oral transmission" of the disease, and it's not known whether that viral matter found in stool is infectious.
The risk is expected to be minimal, however, based on evidence from related coronavirus outbreaks like severe acute respiratory syndrome (SARS) and Middle East respiratory syndrom (MERS), according to the CDC.
Similarly, the World Health Organization classifies the risk of catching COVID-19 from contact with an infected person's feces as "low." But because there is a risk, the WHO's website advises people to wash their hands regularly after using the bathroom and before eating.
Schaffner said concerns about passed gas spreading the disease likely have roots in the 2003 SARS outbreak, where there was transmission of the virus associated with sewage aerosols. At the Amoy Gardens apartment tower in Hong Kong, hundreds of people were infected with SARS, which medical experts connected in part to airborne sewage droplets that resulted from dried-up water traps.
But Schaffner said that in places with modern plumbing today, that's also an unlikely form of spread since fecal matter is flushed down the toilet and the system keeps the gases from coming back up. The CDC has not reported any evidence that COVID-19 has spread by sewage, so far.
Dr. Ravina Kullar, infectious diseases expert for the Infectious Diseases Society of America and an adjunct faculty member at UCLA, said transmission of infections through passed gas, in general, would be abnormal. For example, she said clostridium difficile – a bacterial infection that is contagious and found in stool – has not been shown to be contagious in that way.
"This organism has been around for years, so this is not as new as the SARS-CoV-2," she said. "And as of now, we've not shown that if someone that's harboring this bacteria that they're able to transmit it to someone else through passing gas."
She said that clothing also serves as a sort of filter, referring to the same study Tagg had cited in his Twitter thread.
But either way, if a person is property practicing social distancing and proper hygiene, there shouldn't be an issue with spreading the virus, she said.
"Social distancing is important, and just honestly a good rule of etiquette for life in general is not farting around other people," she said.
Ultimately, Schaffner said, while it's theoretically possible, there's no evidence and doesn't appear to be a reason for people to worry about contracting COVID-19 from passed gas.
"To make an analogy: If you asked me, 'Could you walk from New York to San Francisco?' Yes. Most of us travel by other means, however," he said. "It's about that likely."
Our ruling: False headline
There's not enough proof yet that passed gas has been a form of spreading the coronavirus.
According to the CDC, health experts have so far not identified fecal-oral contamination as a factor in the virus' transmission. The WHO lists the risk of contamination from feces as low. There's also no evidence that feces or traces of fecal matter contained in passed gas have caused the COVID-19 disease. Infectious disease experts interviewed by USA TODAY also said it's highly unlikely.
While the Daily Star's reporting regarding Tagg's tweets is not factually incorrect, the wording in the article's headlines could mislead readers into thinking there is solid evidence or a medical consensus around this kind of spread, when there is so far a lack of proof.
Our fact-check sources:
- Daily Star: Coronavirus "could be spreading across the globe through farts" claim doctors
- Centers for Disease Control and Prevention Emerging Infectious Diseases journal: Detection of Novel Coronavirus by RT-PCR in Stool Specimen from Asymptomatic Child, China
- The British Journal of Medicine: Hot air?
- The Lancet: Prolonged presence of SARS-CoV-2 viral RNA in faecal samples
- Centers for Disease Control and Prevention: Water and COVID-19 FAQs
- Centers for Disease Control and Prevention: COVID-19 FAQs
- World Health Organization: Q&A on coronaviruses (COVID-19)
- Washington Post: In Hong Kong apartment tower, SARS virus spread through plumbing
Ian Richardson covers the Iowa Statehouse for the Des Moines Register. Reach him at firstname.lastname@example.org, at 515-284-8254, or on Twitter at @DMRIanR.
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