The coronavirus causing a heavy acute respiratory syndrome (SASR-CoV-2) is COVID-19 cause of illness. Owing to the emergency situation connected with spread of a coronavirus in many countries of the world the quarantine was initiated. Its influence on health, business activity and other aspects of everyday life is felt both on individual, and at the public level. For lack of in the near future effective pharmacological interventions and vaccine a priority is decrease in frequency of infection (flattening of an epidemic curve), and prevention of transfer of a virus — the best of available approaches for achievement of this purpose.
SASR-CoV-2 at close contact is transferred from the person to the person and causes COVID-19. Still it is definitely not defined whether SASR-CoV-2 can be transmitted through aerosols from respiratory drops as in some researches found virus RNA in samples of air, and in others is not present. However availability of RNA of a virus not necessarily means that the virus is capable to replication, keeps ability to infection and can be transferred to the person. Not it is clear, at what distance from the patient the virus can infect others and what optimum physical distancing between people. In the near future (before emergence of effective and safe treatment or vaccine) prevention of COVID-19 will include generally not medicinal interventions, including public measures for mitigation of the consequences of a pandemic. Thus, quantitative assessment of physical distancing in the medical organizations and in the usual conditions which are not connected with health care is necessary to prove safe interaction with patients about SASR-CoV-2 and rendering the help to them. Definition of the close contact or an individual potentially subject to infection helps to stratify risks, to monitor contacts and to develop guidance documents, but these definitions differ in different parts of the world.
To constrain spread of an infection, to reduce incidence and mortality among health workers and another contacting to potentially infected people, the different countries published the normative documents regulating physical or social distancing, many of which contradict each other. Use of front masks with additional resources of protection of eyes or without them is discussed in the leading mass media and heads of systems of public health care, in particular, such controversial issue is mass wearing front masks. Moreover, optimum use of front masks in the medical organizations which was used decades for prevention of infections is problematic because of deficiency of individual protection equipment.
Results of the researches which are available on today's show that the current recommendation to keep physical distancing at least 1 meter is connected with considerable reduction of risk of infection, and the distance in 2 meters can be even more effective. The main advantage of physical distancing consists in prevention of further transfer and, thus, in reduction of risk of undesirable outcomes of the infection caused by SARS-CoV-2. The data which are also available today allow to assume that wearing front masks protects people (both health workers, and the population in general) from infection with coronaviruses, and protection of eyes can bring additional benefit. Use of front masks rendered a protective effect both for health workers, and for people in the usual conditions subject to risk of infection. Such results were received both in frequency, and in the Bayesian analysis that supports use of front masks in any conditions. However any of these means does not provide full protection against an infection, and definition of their optimum role can demand more exact assessment of risk and accounting of a number of contextual factors.
Now there is a number of opinions that SARS-CoV-2 generally extends in the drop way at contact, nevertheless, a number of researches provides proofs that respirators can possess a big protective effect, than surgical masks. From a biology position these data are confirmed by data on presence of the SARS-CoV-2 virus at aerosols and researches in which RNA of seasonal coronaviruses was found in aerosols, formed at an exhalation.
Thus, global joint well organized researches of various ways of individual protection are necessary, and the available researches can be considered as a basis for preliminary recommendations so far.