As it is already well known today, the outbreak of a new koronavirusny infection happened in China, province Wuhan, during the period from December, 2019 to March, 2020. The confirmed cases were registered in all administrative units, but the Province of Hubei became the leader. In this province 84% of all cases in China were registered. Chinese specialists had to deal for the first time with what is a new virus, to describe forms of a disease and to be used the mass sanitary and anti-epidemic actions directed to prevention of spread of a new infection.
It was originally supposed that the Chinese authorities will manage to localize the center of an infection and it will not gain global distribution, but at the end of January, 2020 cases of a new koronavirusny infection began to be registered in many countries of the world and were connected with the facts of trips to China. Actions for prevention of spread of an infection in many countries were not up to the end developed, plus to it the population originally did not treat new flash as to something serious. Emergence of the epidemiological centers with such the countries as South Korea, Italy and Iran became result of it. Considering that population trips to these countries led to a bigger spread of an infection, began to control this process absolutely impossible and on March 11, 2020 the World Health Organization announced the beginning of a pandemic of COVID-19.
Now one of the leading places in the world on number of the patients with a new koronavirusny infection is occupied by the USA and Brazil where more than 40% of the cases of total number infected in the world are registered.
It is considered that today practically all countries of the world were influenced by COVID-19 consequences, but at the same time in the different countries the different epidemiological situation is noted. Especially well it became noticeable after introduction of various restrictive actions directed to reduction of movement of the population and prevention of spread of an infection. In those countries where restrictive actions were entered with delay or were used in the limited volume (Italy, the USA, Great Britain), the considerable incidence and lethality, despite the high level of delivery of health care in these countries is noted. In the countries where, despite lower level of development of health care, anti-epidemic actions were entered in due time and in full, for example, in Taiwan, Singapore, South Korea, there is lower incidence of a new koronavirusny infection.
COVID-19 source, as well as in many other cases of infections with an airborne way of transfer, the sick person is. It is confirmed what even in an incubation interval of people can allocate a virus and become an infection source. Moreover, the most massive allocation of a virus is noted in the last two days of an incubation interval and the first days from the beginning of a disease. This moment was one of factors of fast spread of an infection as often infection occurs from people who still do not know that they are an infection source, the clinical picture at them is absent, and massive allocation of a virus to the environment already takes place to be.
Main ways of COVID-19 broadcast: airborne, air and dust and contact. At the same time the leader is the airborne way of transfer, owing to cough, sneezing or an ordinary conversation at distance less than two meters. Many cases of so-called super-distribution of COVID-19 when one source of an infection, being in badly ventilated room with other people, allocated in the atmosphere of the room a virus at a conversation or singing that led to infection of a large number of people are described. Wearing a mask an infection source at the same time reduces allocation of a virus in the atmosphere. The most optimal variant for decrease in probability of transfer of a virus in the airborne way: wearing mask both potential source of an infection, and healthy people. In that the sense of the mask regime introduced in many countries from the beginning of a pandemic consists.
Other ways of transfer (air and dust and contact) have smaller value. In particular, the contact way of transfer can be realized at direct contact with the infected person. Transfer of a coronavirus through objects can also take place, especially if this subject was polluted by a large amount of the infected material. Also fecal and oral mechanism of transfer of a virus is not excluded.
It is considered that health workers are exposed to the highest risk of infection owing to long contact with the infected aerosols and the surfaces polluted by a virus.