I just focus on the COVID-19 transmission in the environment, many of points need to be answered
First 3 questions I really need help to understand
1. virus is non-live outside the cells, no reports confirmed the isolation of Covid-19 from the contaminated surface (Please help me to find studies on that)
2. How the scientists know that covid-19 survive for a period (short or long) does they isolated or exposed for some environmental conditions and then injected into tested organisms to see if the virus still can cause an infection or no?
3. How much the effective dose of covid-19 to cause an infection and is it differ from one person to another or may be based on the age, gender?
the virus remained viable and infectious in aerosolized droplets for up to 3 hours. When applied to plastic or stainless steel, the virus remained viable for up to 3 days.
Thankyou Mr Pallab, the article is very helpful, i am still looking for more i am going to update my questions more, just to highlight the points which i think need to understand
Thanks Mr Shyam and Hamed, i just looking for a peer reviewed articles to support the answers, some information is common, but we are looking for the more details
Dear Prof. Al-Gheethi!
The case of COVID-19 is evolving all the time so I tried to find for YOU the newest possible information-sources:
1) LinksMedicus.com (2020). "COVID-19 Updates / 16 June 2020 Edition", LinksMedicus - Free Medical News & Perspectives © All right Reversed, Available at: https://www.linksmedicus.com/news/coronavirus-disease-covid-19-updates/
2) Finnish Institute for Health and Welfare (2020). "Coronavirus COVID-19 – Latest Updates", Available at:
https://thl.fi/en/web/infectious-diseases-and-vaccinations/what-s-new/coronavirus-covid-19-latest-updates
3) Resources enclosed
Yours sincerely, Bulcsu Szekely
Many thanks Prof Bulcsu for your effort i really appreciated
Answer to ques 2.
The virus is exposed to certain environmental conditions like varied ambient temperatures, relative humidity and it is kept in that condition for specific time duration . After incubating for desired time period the virus is eluted and is cultured in suitable medium to check whether it can replicate & is quantified by plaque forming units. A kinetic study can be performed by eluting the virus at regular time intervals to determine the duration of its viability in a particular environmental condition.
Ques 3.
In my opinion the viral load has to vary depending upon a person's age, gender, immunity, predisposition to other diseases, duration of exposure with to infected individual, proximity to an infected person & so on.
Ques 1.
If the virus is present in any droplet on a surface then it can get transferred to an individual if that person touches the droplet & consequently touches her/ his nose or mouth.
Take a look at the following RG links.
Article COVID-19 Surface Persistence: A Recent Data Summary and Its ...
Article Potential role of inanimate surfaces for the spread of coron...
Article Sustainability of Coronavirus on Different Surfaces
Article Aerosol and surface stability of SARS-CoV-2 as compared with...
Article Stability and infectivity of coronaviruses in inanimate environments
Thank you Bulcsu Szekely. You have described it in details. Really I appreciated your efforts.
Please have a look at the following document:
file:///C:/Users/Mak/Downloads/WHO-2019-nCoV-Environment_protocol-2020.1-eng.pdf
The infectious dose of viral infection differs from virus to another, it may be < 10 or >1000. With respect to SARS-Cov2, the infectious dose is still unknown but is clearly very contagious. this, in turn, may refer to the infectious dose is very low or the amount of viruses released from infected people to the environment is very large. Currently, the researchers are facing difficult to determine the SARS-Cov2 infectious dose because of the data coming from patients may vary according to the previous health conditions of patients, their immunity, ages, gender, etc. This requires more and more research to determine the infectious dose of this virus.
Contaminated Surface & Covid19 - As per chemistry of surface - although it is a physical phenomenon but Surface is a more probable zone for any kind of Reaction- High area means high risk !. Where Covid droplet attacks to the cells of
UR Tract .https://www.bbc.com/future/article/20200317-covid-19-how-long-does-the-coronavirus-last-on-surfaces
Hi all participants and have a nice week. In the following RG open question I attempt to search causes of the Lombardia hyper cluster of COVID19,
https://www.researchgate.net/post/The_novel_Coronavirus_in_N_Italy_Lombardia_COVID19_2019nCoV_SARSCoV2_shows_a_fatality_rate_compatible_with_SARS-MERS_Why
a very worst case.
In order to obtain data, there are extensive bibliographical lists about
--oral-fecal contagion
--chemicals vs. SARS-CoV/2
--receptor ecosystem
--animal reservoirs
--Guillain-Barrè syndrome
-- co-infection (other local CoV)
-- comparative data vs. others world hyper clusters
I hope this is an interesting point to obtain data for this dramatic situation in N. Italy (and Central Europe), in order to prevent similar evolution in the next future.
-sv-
Aerosol and surface stability of HCoV-19 (SARS ... - medRxiv
www.medrxiv.org › 2020.03.09.20033217v1.full.pdf
PDFMar 10, 2020 -
I strongly recommend you to go through this paper, it has answers to your doubt regarding the persistence of the virus on various surface.
It is not certain how long the virus that causes COVID-19 survives on surfaces, but it seems to behave like other coronaviruses. Studies suggest that coronaviruses may persist on surfaces for a few hours or up to several days. This may vary under different conditions (e.g. type of surface, temperature or humidity of the environment).
It is reported that there are no infections in aircrafts due to the ventilation/filters. But if infections via surfaces would be an important route of infection we would have to expect at least some infections in aircrafts over surfaces. Doesnt the absence of infections in aircrafts prove that surface transmission is not an important transmission route? And isnt the reported persistance on surfaces rather academic and not supported by prooven cases in the real world?
Humidity may be also a key environmental factor affecting the aersolation of the virus:
Preprint Environmental risk factors of airborne viral transmission: H...
please see links-
Contamination of inert surfaces by SARS-CoV-2: Persistence, stability and infectivity. A review
Article Contamination of inert surfaces by SARS-CoV-2: Persistence, ...
COVID-19 rarely spreads through surfaces. So why are we still deep cleaning?
https://www.nature.com/articles/d41586-021-00251-4
Current understanding of the surface contamination and contact transmission of SARS-CoV-2 in healthcare settings
Article Current understanding of the surface contamination and conta...
Regards