The contact way is considered one of ways of transfer of a coronavirus of the new type causing COVID-19. In spite of the fact that as the main way of transfer of a virus the airborne, contact way of transfer also is recognized remains relevant and can lead to infection of the person, especially at high concentration of a virus on surfaces. In this article we will consider efficiency of various antiseptic agents concerning a coronavirus of new type.
In January, 2020 Medline conducted a research in which the efficiency of various antiseptic agents concerning a coronavirus was studied. Further this research was complemented with others. So, what we have today?
The most part of data of the specified research belongs to a local coronavirus of the person (HSOV-) 229E. On the surfaces of various materials this virus keeps viability from 2 hours to 9 days. Influence of high temperatures (30-40 °) reduces viability of the most pathogenic MERS-CoV, TGEV and MHV. At a temperature of 4 ° duration of activity of TGEV and MHV can reach 28 days. A small amount of comparative data with SARS-CoV indicates even big duration of activity of a virus and higher ability to infection. Besides, at the room temperature duration of activity of the HSOV-229E virus increases by 50%, in damp conditions — for 30%.
Research of efficiency of antiseptic agents in a coronavirus inactivation in suspension it was following:
Ethanol (78–95%), propyl alcohol-2 (70–100%), combination of propyl alcohol-2 of 45% and propyl alcohol-1 of 30%;
Glutaraldehyde (0.5-2.5%), formaldehyde (0.7-1%) and povidone-iodine (0.23-7.5%).
The specified substances quickly reduce quantity of a virus as it should be from 4 log 10 above. Sodium hypochlorite is effective in concentration from 0.21%; hydrogen peroxide — in concentration from 0.5% and at an incubation period of 1 minute. The data obtained at a research a chloride benzalkoniya were contradictory as at influence within 10 minutes solution of 0.2% did not show efficiency, however solution of 0.05% showed sufficient efficiency in a coronavirus inactivation. Hlorgeksidina biglyukonat 0.02% it was inefficient.
The research of efficiency of biocides in a coronavirus inactivation at transfer (test carrier) was shown by such results:
Ethanol in concentration from 62% in 1 minute reduces infectivity of a coronavirus as from 2 to 4 log10 to 71%.
Sodium hypochlorite in concentration of 0.1-0.5% and glutaraldehyde in concentration of 2% reduce quantity of a virus even more effectively — more, than in 3 log10.
Efficiency of various antiseptic agents concerning a coronavirus
On the contrary, benzalkoniya of chloride of 0.04%, sodium hypochlorite of 0.06% and orthophthalic aldehyde 0.55 showed smaller efficiency.
It is necessary to notice what for effective cleaning and disinfection of premises of WHO recommends to use the water and cleaners which are usually applied in hospitals (for example, sodium hypochlorite). Solution of sodium hypochlorite of 5% in the ratio 1:100 is usually used that gives as a result concentration of solution of 0.05%. The research discussed in article contains data on efficiency of sodium hypochlorite of 0.1% within 1 minute, thus, authors recommend to dissolve sodium hypochlorite of 5% in the ratio 1:50. For disinfection of small surfaces the comparable efficiency was shown by ethanol in concentration of 62-71%. WHO also recommends ethanol of 70% for these purposes.
Authors of a research note that they have no data on the recommended frequency of washing of the hands which were in contact with a virus and also on the virus loading which is transferred to hands after contact with the infected patient or a surface viruliferous.
It should be noted that two formulas of antiseptic agents recommended to WHO on the basis of 80% of ethanol and 75% of propyl alcohol-2, were effective for an inactivation of SARS-CoV and MERS-CoV. On the basis of these formulas now effective alcohol-containing antiseptic agents which are applied both by health workers in healthcare institutions, and broad masses of the population are also created.
It is worth remembering that the coronavirus of the person can remain active on surfaces of at least 9 days. Virulence of a virus during this time remains a subject of researches. Disinfection by solution of sodium hypochlorite of 1% or ethanol of 62-71% considerably reduces infectivity of a coronavirus in 1 minute of influence of solution. The comparable efficiency is expected also concerning SARS-CoV-2.
Also It should be noted that the solution of a hlorgeksidin of the biglyukonat used in some institutions and the population of 0.02% proved to be inefficient concerning a coronavirus. The question of efficiency of solutions of a hlorgeksidin of the biglyukonat in higher concentration is still open and can become a subject for further researches.