# Does flushing the toilet really spread the new crown virus?

Beijing time July 10 news, according tomedia reports, the new crown virus is rampant around the world, we often can see the news that the new crown virus or can be spread through flushing toilets, is it true? Using computer simulations, researchers found that the vortex generated when the toilet flushed can disturb the air in the toilet. The mathematical model is too complex to explain in detail here. Simply put, there is a need to understand the vortex, as well as the energy conversion at the junction of water in the toilet and the air on the surface of the water.

“Researchers observed a large number of viral particles moving upward, and about 40 to 60 percent of the virus particles crossed the toilet seat, causing widespread transmission of the virus,” one report said. “

In fact, instead of using real virus particles, the researchers took into account the average size and weight of the new coronavirus in their calculations. Suppose that the conditions include the amount of water, the size of the toilet, and the force of the water that causes the vortex. Although the number and extent of virus particles assumed in the study is fairly accurate, there are two assumptions that are worth examining in depth from a biological perspective. They hypothesized that there were 6,000 viruses in the toilet, and that to cause “widespread virus transmission”, the particles would have to survive. This leads us to the next question: How accurate are the two assumptions? What do we know about the fecal transmission mechanism of the new coronavirus?

The first case of new coronary pneumonia reported in the United States showed symptoms of abdominal pain, and RNA of the new coronavirus was detected in the feces. About 15 percent of u.S. patients with the condition. A study of patients in Wuhan also found that about half of the new crown-positive patients had the virus in their feces and did not necessarily have symptoms of abdominal pain. After the patients tested positive for the virus in their respiratory tracts, the virus began to appear in the feces and continued until 11 days after the respiratory test. However, these results are based solely on the presence of viral RNA and do not measure the viability of the virus itself. Ten thousand steps back, we know that the digestive tract can excrete the new coronavirus, so there will be some new coronavirus particles in the toilet, but can these viruses survive and infect others?

Answer in one sentence: We don’t know yet. In a laboratory study, fluids in the large intestine reduced the vitality of the new coronavirus by 80 percent in an hour, and “the infectious virus was almost impossible to detect after 24 hours”. Of the 10 fecal samples taken by patients with new coronary pneumonia, three were found to have viral RNA, but none of them developed an infectious virus after virus culture. In another study, which cited the study, the researchers put in 20,000 CFU (colony-forming units) of C. difficile in the toilet, and eventually detected about eight CFUs in the air on either side of the toilet. Finally, there are studies that show that RNA evidence of viruses (especially gastrointestinal noroviruses) can stay in the toilet for a while.

Aerosols produced when flushing the toilet can spray microbes, including the new crown virus, into the air, about 90 cm above the ground, so most adults don’t have to worry about inhaling these particles. However, these particles may fall on the toilet seat and the surrounding floor. But there is little evidence that these particles are contagious, and there are no reports of fecal infections in patients.

The researchers suggest that covering the toilet cover when flushing can reduce the amount of aerosols sprayed into the air, but that they stick to the toilet cover. They also recommend wiping a seat circle before sitting down and washing your hands after sashimi. But during the outbreak, these should have become our daily habit. (Leaf)