Article/Review by
H/Dr. Abdul Wahid Anwar,
Pakistan
Email: wahidrwp@live.com
Introduction:
SARS-CoV stands for Severe acute respiratory syndrome corona virus infected people in 2003 about 30 countries of 5 continents caused over 8,000 human infections and about 800 death cases. Severe acute respiratory syndrome (SARS), was a newly emerging disease associated with severe pneumonia and spread to involve over 30 countries in 5 continents in between November 2002 and September 2003. {Refer:1}
Cause
It was considered as zoonotic i.e spread from an animal that may be spread in 2002 indirectly from bats and then to other animals (civet cats) and then infected humans in the Guangdong province(southern China).
Symptoms:
The symptoms are
- influenza-like
- fever(mostly)
- headache
- diarrhoea
- myalgia,
- malaise
- shivering (rigours)
- No single symptom or collections of symptoms for SARS specifically (means it will vary from person to person)
- In some cases, SARS patient is not declared at initial stages the patient with elderly and immunosuppressed patients. {Refer:2 (WHO)}
Mostly the SARS-CoV spreads from one body to another body in the form of small droplets during respiration (or respiratory droplets) indirect manner and also by fomite i.e spreading of virus or infection by touching som object surface. viruses do not multiply outside the living body and persist on different surfaces of the environment.
The SARS-CoV spread rapidly incase of faecal contamination.
The SARS-CoV rapid spreading was reported when Amoy Garden in Hong Kong attacked more than 300 residents in a block of single-apartment by contaminated sewage.
Detection of SARS-CoV
It can be detectable in excreta and fluids of the body.
Survival of corna virus on temperature, humidity and other factors
virus which is in the dried environment can survive at the temperature range of 22-25°C about 5 days such condition is achieved at air conditioner environment.
The survival rate will be reduced at a higher temperature and higher relative humidity. That is why Asian countries in tropical area i.e with higher temperature were not affected.
The common cold-related corona virus in human observed by the results that its viability is only for 3 hours on environmental surfaces after drying but its viability increased in liquid suspension for several days.RSV and parainfluenza viability when placed on dry surfaces about 6 and 2 hours respectively. {Refer: 3,4}
Parainfluenza and RSV viruses were viable after drying on surfaces for 2 and 6 hours, respectively the coronavirus 229E is less stabilized in high humidity when in aerosolised form.
Studied on SARS CoV explain that it can survive for 2 weeks after drying provided the humidity and temperature were at the environment of the air conditioner. By taking virus in the liquid, the environment is stable at room temperature for 3 weeks. Such conditions can be seen in figure/graph 1 & 2.
viral titre reduction vs time graphs
Figure/Graph 1: Infectivity of SARS Coronavirus (105/10 μL) to different
temperatures at >95% relative humidity
Figure/Graph 2: Interactivity of SARS Coronavirus (105/10 μL) to different
temperatures at >80–89%.
Graph Images courtesy by: K. H. Chan published on Research Article
virus titre vs Incubation time graph
According to the figure/graph 3 (a), at room temperature virus infection titres decreases among four viruses tested in accordance with time present in dried form(not in suspension) with protein added and according to the figure/graph 3 (c), at room temperature virus infection titres decreases among four viruses tested in accordance with time present in suspension with protein added.
▲ SARS-CoV (FFM1), ♦ h-CoV (E229), ■ HSV-1, ● adenovirus type 3
Graph 3 (a&b) source:
H. F. Rabenau, J. Cinatl, B. Morgenstern, G. Bauer, W. Preiser & H. W. Doerr
Stability and inactivation of SARS coronavirus
Studied shown that the human corovirus named as 229E and OC43 are less stable than SARS-CoV. SARS-CoV is even more stable than the other viral respiratory pathogens i.e. respiratory syncytial virus. So considering such conditions, SARS-CoV is a strong virus as it may potentially be transmitted not even by direct but indirect manner i.e fomite (The objects which are infant carriers for infections i.e utensils, clothes etc.).
The contaminated surfaces of virus can easily cause the spreading of virus infection in public places even in hospitals.
The unsatisfactory condition of sanitation and sewage disposal systems causes the intense spread of SARS-CoV.
The high temperature and high relative humidity cause reduction survival rate by reducing viability effects of the SARS-CoV.
{Refer: 9 & 10}
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References/Sources:
{Refer: 1} Stability and inactivation of SARS coronavirus
H. F. Rabenau, J. Cinatl, B. Morgenstern, G. Bauer, W. Preiser & H. W. Doerr
Medical Microbiology and Immunology volume 194, pages1–6(2005)
{Refer: 2} https://www.who.int/ith/diseases/sars/en/
{Refer: 3}C. B. Hall, R. G. Douglas, and J. M. Geiman, “Possible transmission by fomites of respiratory syncytial virus,” Journal of Infectious Diseases, vol. 141, no. 1, pp. 98–102, 1980.
{Refer: 5} J. Sizun, M. W. N. Yu, and P. J. Talbot, “Survival of human coronaviruses 229E andOC43 in suspension and after drying on surfaces: a possible source of hospital-acquiredinfections,” Journal of Hospital Infection, vol. 46, no. 1, pp. 55–60, 2000.
{Refer: 6} The Effects of Temperature and Relative Humidity on the Viability of the SARS Coronavirus K. H. Chan , J. S. Malik Peiris, S. Y. Lam, L. L. M. Poon, K. Y. Yuen, and W. H. Seto Department of Microbiology, The University of Hong Kong, Queen Mary
Hospital, Pokfulam, Hong Kong
{Refer: 7*}WHO Report, “First data on stability and resistance of SARS coronavirus compiled by members of WHO laboratory network,” http://www.who.int/csr/sars/survival_2003_05_04/en/#.
{Refer: 8*}M. Y. Lai, P. K. Cheng, and W. W. Lim, “Survival of severe acute respiratory syndrome coronavirus,” Clinical Infectious Diseases, vol. 41, no. 7, pp. e67–e71, 2005.
{Refer: 9*}K. Lin, D. Y. K. Fong, B. Zhu, and J. Karlberg, “Environmental factors on the SARS epidemic: air temperature, passage of time and multiplicative effect of hospital infection,” Epidemiology and Infection, vol. 134, no. 2, pp. 223–230, 2006.
{Refer: 10*}C. B. Hall, R. G. Douglas, and J. M. Geiman, “Possible transmission by fomites of respiratory syncytial virus,” Journal of Infectious Diseases, vol. 141, no. 1, pp. 98–102, 1980.
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