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The likely survival of coronavirus in an open environment
Material posted: Publication date: 09-02-2020
Maybe you are already tired of this topic. However, my novel has only just begun. This publication is part of the huge publications:(more than 80000 letters). I decided to do it separately

Since only part read my full publication and have questions.
Some of the questions already have a likely answer, I decided to put up a couple of sections of his article.
Was asked this question: as coronavirus with temperature? Answer: in any case, do not low temperature!.. Understand survival in the open environment of a typical coronavirus.

I was again overtaken. I started to dig in the area of remedies, the article is already out. There is a certain advantage: I need less work. Here I added what was not information. The rest you can read in the FAQ on respiratory protection and disinfection.

I will continue to answer some of the unanswered questions in the form of mini publications for 10 thousand words. Everything else in my big publication on 100000 of thousands of letters(with spoilers)
Everything else about the coronavirus Personal research about 2019-nCoV(more than 80000 letters).

Advanced facts

A family of RNA viruses, including January 2020, 40 types of viruses combined into 2 subfamilies.They were named because of the structure of its shell in the form of a crown. Coronaviruses are viruses with a positive chain RNA (+RNA) compared with other RNA viruses have exceptionally large genomes(thousands of base pairs) and use a complex strategy of genome expression. Viral particles(virions) of spherical shape(with some signs of polymorphism) with a diameter of 75-160 nm(size 2019-nCoV from 60 to 140/~120 nanometers in diameter). The height of the protrusions of different coronaviruses is on average 12-24 nm(2019-nCoV 9 — 12).

The first coronavirus was isolated in 1965 in a patient with acute rhinitis. In 2002-2003, in China there was a virus SARS-CoV. (8000 cases and 800 dead). In 2012, MERS-CoV. In late 2019-early 2020 2019-nCoV. In addition to the zoonotic SARS - and MERS-CoV, there are four set of human coronavirus (HCoV).

Coronaviruses have a single chain RNA genome that encodes 4-5 structural proteins, including a protein outer shell (N) protein matrix (M) protein, small envelope (E), spike (S) glycoprotein that provides the binding and entering of cells and some beta-coronavirus protein(glycoprotein)(HE) that some viruses use the shell as a mechanism for invasion. HEs helps in attachment and destruction of specific sialic acid receptors located on the surface of the host cell... 0.

They have polycistronic organization of the genome and use a unique mechanism of transcription for the generation of a nested set subgenomic (sg) mRNA. Different types of coronaviruses infects people, cats, birds, dogs, cattle, pigs, and rabbits, bats, camels, and other animals. 2019-nCoV: Kingdom:Riboviria, Type:Incertae Sedis, Order:Nidovirales, Family:Coronaviridae, Genus:etacoronavirus, Subgenus:Sarbecovirus

Divided into 4 kinds, which are called the alpha-coronavirus and beta-coronavirus, gamma -, and Delta coronavirus-coronavirus 1.

Complete genome 2019-nCoV now stored online in GenBank: MN908947.3.

HCoV-NL63 and HCoV-229E belong to the alpha-coronaviruses(120-160 nm), whereas HCoV-OC43, HCoV-HKU1, SARS-CoV, MERS-CoV, 2019-nCoV belong to the beta-coronavirus, 1 and 2

The adaptability of the coronavirus to the owner

Many of the proteins of the coronavirus expressed in the infected cell, facilitate the interaction of coronaviruses with the host. For example, by interaction with the host cell to create an optimal environment for replication of coronavirus, by changing the gene expression of the host or counteract the antiviral defense of the host. Many of these interactions affect the outcome of infection, including adaptation and transfer of the species limit. The number of mutations in receptornegative domain protein of SARS-CoV spike (S), to jump the species limit was negligible.1.Li et al. 2005c (see Chapter 2). .

Chemicals that suppress or delay the physico-chemical processes peptidase does not influence the penetration of the virus. This indicates that the use and penetration of the receptor for SARS-CoV and MERS-CoV and, consequently, 2019-nCoV does not depend on the activity of the receptor peptidase. They depend only on binding to these specific receptors-owners.1.

Introductory information on the survivability of viruses

There is the assumption that the environment is formed after a certain time in disguise helps to preserve the virus for a longer time. Because of this, there are some risks to get infected touching the mask and transferring the virus.

Water, the common means of transmitting viruses, can contribute to their survival, but many environmental factors will have an adverse effect on the population of viruses.
The preservation of wet dressings may contribute to the survival of the virus. One such study:a Study of survival of a typical virus in the aquatic environment

In the absence of host cells the viral populations in the environment can only decrease or remain stable. Assessment and analysis of the shape and intensity of this reduction represent the main research objectives of viral inactivation.

Higher temperatures mean more rapid inactivation of virus. At low above zero temperatures, viruses can survive for long periods of time
often longer than the duration of the study. Survival in cold conditions
At higher temperatures, the viral population will be reduced by several orders of magnitude within a few days. Population reduction at higher temperatures
The freezing temperature allows the virus to remain stable at least within a couple of months, but in the early days, you may experience an initial decline.Survival of viruses in temperatures below zero.

Sunlight is another important factor that contributes to virus inactivation under the action of ultraviolet radiation. The presence of an indigenous microbial population has a negative impact on the survival of the virus. The presence of organic substances in water has a positive effect on the survival of the virus.Other factors responsible for increased viral inactivation,
include the presence of disinfectants.

The increase in temperature is the main factor affecting the survival of the virus in the environment, through the denaturation of proteins, damage to nucleic acids or disintegration of the outer shell of the virus(capsid) Mechanism of inactivation Activity of sunlight can be attributed to damage of nucleic acids by formation of pyrimidine dimers or other products may involve other mechanisms, such as excitation of the active substances present in the outer shell of viruses in the environment.

Regarding more specific data Was conducted a few studies on the effectiveness of masks, the majority of them were field studies that investigated group of patients the effectiveness of the intervention.Review:1 and 2

Was done prospective cluster-randomized study that compared surgical masks are not tested P2 masks, and no masks in prevention of influenza-like illnesses (ILI) in households.It was found that adherence to mask use significantly reduces the risk of infection related to GPP,
but <50% of the participants most of the time wore masks.

However, during a severe pandemic when use of face masks can be more, the spread of the pandemic in households can be reduced.Thus the efficiency increase with the number % of native masks.

Assessment other measures: closing schools 1 and randomised controlled trials for hand washing
1,2,3,4,5,6,7,8,9,10

Other factors responsible for increased viral inactivation include the presence of disinfectants such as chlorine 1,2,1,1, extreme pH, 1,1, copper1 , or aeration. The effects of some factors such as water hardness, less reliably proven1

The size factor, survival and transmission of the virus against treatment methods

The relatively large size 2019-nCoV (~29.9 thousand base pairs and the average 120нм, 60 min) and the lipid shell makes it susceptible to the stages with the inactivation of the virus incl used during the manufacturing processes, such as surface-active agents solvents (S / D) 1, waste management(incubation with low pH), the use of caprilate, pasteurization 1 or heat treatment, 1,2, nanofiltration processes or fractionation... the Efficiency of these processes has been demonstrated in other model viruses with a lipid envelope that is very similar to 2019-ncov, such as the human coronavirus 229E and OC43, SARS-CoV and porcine coronavirus TGEV.
Based on these data, it is possible to be more or less sure that a sufficient margin of safety compared to 2019-nCoV. Viral particles of SARS-Cov is sensitive to treatment with lipid solvents, nonionic detergents, oxidizing agents; SARS-Cov is stable in feces and urine at room temperature for at least 1-2 days, especially if diarrhea is present (high pH);

Discovered minimal loss of infectivity through 21 days at 4 degrees Celsius. Heating to 56 °C to inactivate coronavirus quickly.1.

The bulk of the spread of airborne droplets. Up to 100 million genomes per ml are found in the secretions from the nasopharynx. In 32% of cases in patients after an average of 3.2 days after the onset of illness and in 68% at day 14 Viral RNA detected in stool samples with 97% of patients after 2 weeks of disease and in 42% of urine samples. Strongly suspected fecal-oral transmission.1.

Information on the survivability of coronavirus on surfaces

The data presented in the SARS.Given the similar features of coronaviruses(with differences, for example, in a receptor-binding domain(RBD)) you can quite reliably predict the situation.

Given the fundamentals of the theory presented in the previous paragraph, you can try to predict features for the survival of the virus outside the body. In one of the research articles the surface of the environment was recognized as likely factors contributing to the transmission of hospital-acquired viral infections 1.

The question of whether the surface of the hospitals role in the spread of nosocomial viral infections, has acquired a special relevance in the context of recent news.

During the outbreak of SARS coronavirus (SARS-CoV) was discovered nucleic acid of SARS-CoV on surfaces and inanimate objects
0

There is a possibility that the surface may be sources of transmission of the virus. Risk assessment requires data on virus inactivation on surfaces of the environment and data about how
as for inactivation of the virus is influenced by environmental variables such as air temperature (AT) and relative humidity (RH) and more.

Due to the fact that to explore the most dangerous coronaviruses need specially trained personnel working in a laboratory of Biosafety level 3 (BSL-3),
there are big problems in the study of this virus and are available only limited data on the survival of coronavirus and reactions to stressful environmental factors.

The results show that with the deposition of a large number of surrogates, these viruses can persist for several days on surfaces in the environment AT and
in a wide range of levels of relative humidity (from 20 to 60% relative humidity), typical of environments of health.

The coronavirus may be more resistant to inactivation on surfaces than previously studied coronaviruses of man. It was reported that SARS-CoV could survive for 36 hours in stainless steel
0However, the conditions AT and RH for the previous experiment were not presented, making comparisons difficult. Rabenau and coauthor of 0 reported a much slower inactivation of SARS-CoV on the surface of polystyrene (a reduction of 4 log 10 after 9 days; conditions AT and RH were not reported),
which is consistent with some observations of TGEV and MHV

The survival of the virus was increased by reducing AT. Similar to the relationship between AT and virus inactivation was observed for viruses with the shell in the fluids and aerosols.
Data on coronavirus obtained in this study suggest that, although the rates of virus inactivation is lower at lower at, still various effects of RZ on the survival of viruses every at.

AT at ambient (about 20 °C) coronaviruses can survive for 2 days, losing only 1-2 log 10 infectivity, depending on the relative humidity. With decreasing temperature, the survival rate of the virus will rise. The virus can survive weeks at a temperature of -1.

On the basis of data on survival can be assumed that viruses with sheath can remain infectious on surfaces long enough to allow people to get in touch with them, creating a risk of infection, which leads to infection and the possible transmission of disease.

The relationship between inactivation and RH is not monotonic, was a higher survival rate or a higher protective effect at low RH (20%) and high relative humidity (80%) than at moderate RH (50%). There was also evidence of interaction between AT and RH.0

There is a question about the heating in the building Neuromantix: 0 about the heat in the building.
0 the Results indicate that we need additional calculations of the correlation of relative humidity and different temperature. Pick up at home the optimum ratio of temperature and humidity too hard. Increasing the temperature gives more stable results in most cases.

Most likely no practical research to improve the indoor temperature as a factor reducing risks. However, based on information on the temperature can try to raise the temperature.Humidity you can choose according to taste. However, fully protected in this way is impossible.0. To provide a high rate of inactivation of the virus it is necessary to provide greater temperature than 28-30 degrees.

On the basis of 1 and 1 SARS has inaktivirovanie ultraviolet light (UV) at 254 nm,
heat treatment at 65 ° C or greater, alkaline (pH> 12) or acidic (pH <3) conditions, treatment with formalin and glutaraldehyde. Liquid samples of bovine plasma did not contain detectable viable PPV after 15-minute exposure (the cumulative UV-C irradiation 2295 j / l)1 the Bad news SARS like virus(2019-nСov) inaktiviruet for a minimum period of 15 minutes at 56 degrees or 254 nm. Better 20 minutes at 254 nm, It worsens the consequences. Not every time you want to spend so much time. 1 With a smaller time increases the probability of survival of viral particles.To preserve the possibility of division of virus inactivation with little information.

For nasal irrigation(rinsing the nose) is not so much information. 1 of Course no information on 2019-nСov or SARS. To carry out such studies very difficult.There are many methods of washing. Not all of them were investigated.
1
In the control group achieved significant improvement.It may come as an additional method of risk reduction in addition to washing hands and other methods.
However, each exit from the house will melt the whole mission and to keep track of everything is difficult.

May need to keep a personal and group home statistics, and noted the implementation of measures for inactivation at the exit and entrance.Only in this case it is possible to achieve effective results.

Summary: the likely persistence of the virus

The filter performance individual filter masks for the face (FFR) and filter cartridges for particulate N95 and P100 approved by NIOSH, was investigated against the viable MS2 virus, a non-pathogenic bacteriophage, aerosolized from a liquid suspension.Size (23-28 nm) the Tests were performed in two conditions of cyclic flow (minute volume 85 and 135 l / min) and two constant flow rates (85 and 270 l / min).
The average viable MS2 penetration through FFR / N95 cartridges and P100 was typically less than 2, and 0.03%, respectively, under all flow conditions.

Given that the minimum sample coronaviruses exceed the size of the MS2 at least 40-60нм.
It is possible to ascertain a reasonable margin of safety for respirators FFP2 and N95 if a good facial seal. The respirator with particulate filter N99(FFP3) filters at least 99% of airborne particles but is not resistant to oil. 1

Over time, the degradation of the protective capabilities of respirators. There is the assumption that the environment is formed after a certain time in disguise helps to preserve the virus for a longer time. Because of this, there are some risks to get infected touching the mask and transferring the virus. For filter respirators is the Ukrainian scientific article. The value is degraded.
1

The number of bacteria on the surface of the mask increases with increasing time of operation; a significant difference was found between the 4-6-hour and 0-hour groups (p <0.05).
1. You need to replace the masks because of the slump in quality of antibacterial protection.
For example, here is the degradation of static charge:1,2

Probably the heated breath and moist dressings saving coronavirus will increase.The necessary practical research on the subject. Probably especially for inactivation 2019-nCoV, in General, similar to SARS, but I would like to see real case studies for this reason. Factor in the maintenance of the virus in an open environment may be another unaccounted factor influencing the spread of the virus.

Water, the common means of transmitting viruses, can contribute to their survival, but many environmental factors will have an adverse effect on the population of viruses.
The preservation of wet dressings may contribute to the survival of the virus. One such study: a Study of survival of a typical virus in the aquatic environment

Regarding more specific data Was conducted a few studies on the effectiveness of masks, the majority of them were field studies that investigated group of patients the effectiveness of the intervention. Review:1 and 2

Some of the links

Human Coronavirus EMC Does Not Require the SARS-Coronavirus Receptor and Maintains Broad Replicative Capability in Mammalian Cell Lines — — mBio, 11.12.2012, doi: 10.1128/mBio.00515-12
Severe acute respiratory syndrome
2019-nCoV
A study of the infectivity
The opinion of the epidemiologist
www.medrxiv.org
china-coronavirus-hong-kong-medical-experts-call
Receptornegative domain as a target for the development of vaccines against SARS.
Who report on the number of cases
article
article
The who website
The necessary funds for the treatment of the virus
1
2
3
4
5
6
7
8
9
10
10

And another 1,000 links that I will add.Some of the links look right at the text.

Source: https://habr.com/ru/post/486484/

Tags: assessment


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