Take a dive and get sick? How safe is swimming during the coronavirus

Irina Mishina

Rospotrebnadzor (The Russian Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing) a few weeks ago spread encouraging information. "The virus is an intracellular parasite, it lives in human cells. In the environment or on the surfaces, its viability is very limited, including temperature. When heated from 30 degrees or more, it loses its infectious activity. The coronavirus is completely deactivated at a temperature of plus 70 degrees Thus, the likelihood of contracting by contact in hot weather is minimal, but it remains airborne", - explained the Center for Molecular Diagnostics, Central Research Institute of Federal Service for Supervision of Consumer Rights Protection and Human Welfare.

Moreover, the behavior of coronavirus in the aquatic environment is still largely a mystery. Neither in the Second Moscow Infectious Diseases Hospital on Sokolina Gora, nor in the Russian Academy of Natural Sciences, and even in the Ministry of Health, were they able to give a concrete answer to the question, in what aquatic environment, at what temperature and other conditions can coronavirus infection be maintained.

“We have not conducted such studies yet. It is necessary to look at foreign sources. One way or another, the coronavirus epidemic has not disappeared. Moreover, we are waiting for the second wave. After taking strict anti-epidemic measures, many decided that everything is possible: I often see young people without masks in public transport, in stores ... The incidence rate has decreased by several times, but the infection transmitted by airborne droplets is still present in the air. Therefore, one must be extremely careful, especially on vacation, ”the infectious disease specialist at the Infectious Diseases Clinical Hospital No. 2 on Sokolinaya Gora, MD, professor Vera Makashova said.

Foreign sources have really long been interested in the possibility of the spread of coronavirus in water bodies. A group of researchers led by scientists from the University of Barcelona discovered the presence of a new type of coronavirus / COVID-19 / in wastewater samples taken in Barcelona last March. At least, such information was published by the University of Barcelona. The report indicates that researchers at the University of Barcelona Enterovirus Infections Group have analyzed local wastewater samples. According to the results of the analysis, a trace of СOVID-19 was detected in the sample dated March 12, 2019. Previously, researchers already found the presence of the virus in wastewater samples dated January 15 of this year. Moreover, the first case of COVID-19 infection in Spain was registered only on February 25 of this year.

Also, a study of the Medical University in Poznan (Poland) was published in the public domain . To summarize this voluminous work, the conclusion is the following: a coronavirus infection can spread through water. “The lifetime of the coronavirus bacteria in the aquatic environment depends on the composition of the water, its temperature, depth, and insolation,” the study says. True, this article studied the behavior in the aquatic environment not of COVID-19, but of other, long-known coronavirus infections. The article, in particular, states: “ In seawater, the coronavirus dies almost immediately, in lakes and rivers it can live from several hours to several days. In the surface layers, where insolation and ultraviolet radiation are stronger, the coronavirus bacteria die faster. The longest coronavirus lives at a water temperature of 10 to 20 degrees. The higher the temperature, the faster the coronavirus bacteria die , ”stated a study by Polish scientists.

Nevertheless, we decided to find out the point of view of Russian scientists on this problem.

“Coronavirus is transmitted by airborne droplets. That is, it can be transmitted if we swallow water, which the person infected with the coronavirus had spat out before. The preservation of coronavirus in water is affected by its temperature. Viruses are generally afraid of heat. In the laboratory, we store viruses at a temperature of minus 10 degrees Celsius. Water temperature above 20 degrees Celsius may already be fatal for the virus, - told "NI" doctor of medical sciences, member of the Presidium of the Russian Academy of Natural Sciences, head of the Department of Microbiology of Latent Infections of the Research Center of Epidemiology and Microbiology named after Gamaleya Victor Zuev . - Sea water is harmful to viruses, as it contains salt. I can say with a high degree of probability that if it gets into sea water, the coronavirus, if it lives, is extremely short-lived. Another thing is if a person infected with COVID-19 spits in the water and it gets into the respiratory tract or the oropharynx of another person who was nearby. In this case, infection can not be avoided. Therefore, even at sea, one must keep a distance. Nevertheless, it is unlikely to become infected with coronavirus in seawater: salt destroys COVID. Plus ultraviolet radiation, sunrays - all these factors destroy the coronavirus”, - said professor Viktor Zuyev.

In addition to relaxing in the resorts, many this year chose self-isolation in their summer cottages. However, the heat will surely make summer residents leave for water bodies - lakes and rivers. What is the likelihood of infection in the water in this case? “A new type of coronavirus when it enters river water can survive up to 25 days". This follows from a study published on the medical portal medRxiv.

Is it so?

“The lower the temperature of the water, the higher the likelihood of coronavirus infection remaining in the pond”, - explains the virologist, the head of the Department of Microbiology of Latent Infections of Epidemiology and Microbiology Research Center named after Gamaleya Victor Zuyev. "The chance of coronavirus infection in running river water is lower than in stagnant lake water. Also, when bathing, you should avoid places near the sewage discharge. Wastewater is a favorable environment for the spread of any virus”, - said Professor Zuyev.

It turns out that a person who chooses to rest by the water and swimming, is in any case at risk?

“Do not drink from ponds. It is necessary to observe the distance when swimming, to stay away from people both on land and in water. In this case, the risk of getting coronavirus is minimal. There is another way out for the lovers of swimming - these are pools with chlorinated water. Chlorine is known to be detrimental to the virus”, - biochemist Veniamin Zaitsev told NI.

In a pandemic, any place where there is a crowd of people will be dangerous in terms of the spread of coronavirus. This should not be forgotten even on vacation. Having opened the beaches, Rospotrebnadzor would have liked to at least hang out the шinformation signs on anti-epidemic measures in water bodies. Not to mention conducting and publishing serious studies on the spread of coronavirus in the aquatic environment.