Emergence of a Zoonotic Pathogen - Novel Coronavirus (SARS-CoV-2) in the Context of Changing Environment

  • Sajal Bhattacharya Associate Professor, Post Graduate Department of Zoology, Asutosh College (University of Calcutta), Kolkata, West Bengal, India
  • Shakya Sinha Post Graduate Student, Post Graduate Department of Zoology, Dinabandhu Andrews College (University of Calcutta), Kolkata, West Bengal, India
  • Debasmita Baidya Research Scholar, Post Graduate Department of Zoology, Asutosh College (University of Calcutta), Kolkata, West Bengal, India.
  • Rina Tilak Scientist ‘G’, Dept. of Community Medicine, Armed Forces Medical College, Pune, Maharashtra, India. https://orcid.org/0000-0003-3781-0210
Keywords: SARS-CoV-2, Reservoir Host, Man-animal Encounter, Climate Change, Deforestation, Travel and Trade


A newly discovered strain of coronavirus is the causal agent of COVID-19 pandemic. Preliminary findings suggest that this novel coronavirus - Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) might have originated in bats, and thereafter crossed the species barrier from an intermediate host; eventually spreading within humans. Bat coronaviruses are older than the coronaviruses identified in other animals and have shown a consistent growth rate. The diverse natures of coronaviruses in different bat species have witnessed repeated introductions and occasional establishment in other animal species. The dispersion of animal diseases and zoonotic pathogens is facilitated by rapid globalization, international trading and the ever-growing flow of goods and people. Climate change coupled with globalization and extensive deforestation can act as a significant selection pressure which can lead to onsets of future coronavirus transmission cycles. Climate change alters the availability of viable habitat for the hosts as well which results in the redistribution of host ranges and host densities relative to habitat resources. An attempt has been made in this review to assess and analyze the possible causes of the emergence of a zoonotic pathogen having pandemic potential, the novel coronavirus (SARS-CoV-2) and its subsequent spill over to humans causing COVID-19.

How to cite this article:
Bhattacharya S, Sinha S, Baidya D, Tilak R. Emergence of a Zoonotic Pathogen - Novel Coronavirus (SARS-CoV-2) in the Context of Changing Environment. J Commun Dis 2020; 52(2): 67-73.

DOI: https://doi.org/10.24321/0019.5138.202021


Johnson C, Hitchens P, Evans T et al. Spillover and pandemic properties of zoonotic viruses with high

host plasticity. Sci rep 2015; 5: e14830.

Lu H, Stratton CW, Tang YW. Outbreak of pneumonia of unknown etiology in Wuhan, China: The mystery and

the miracle. J Med Virol 2020; 92(4): 401-402.

World Health Organization. 2020. WHO Director-General’s Remarks at the Media Briefing on 2019-

nCoV. 2020.

Fan Y, Zhao K, Shi ZL et al. Bat Coronaviruses in China. Viruses 2019; 11(3): 210.

Vijaykrishna D, Smith GJD, Zhang JX et al. Evolutionary insights into the ecology of coronaviruses. J Virol 2007;

(15): 8371.

Lu R, Zhao X, Li J et al. Genomic characterization and epidemiology of 2019 novel coronavirus: implications

for virus origins and receptor binding. Lancet 2020; 395(10224): 565-574.

Cutler SJ, Fooks AR, van der Poel WH. Public health threat of new, reemerging, and neglected zoonoses

in the industrialized world. Emerg Infect Dis 2010; 16(1): 1-7.

World Health Organization, 2020. www.who.int (Accessed on 25th April, 2020). Available from:


Kahn JS, McIntosh K. History and recent advances in coronavirus discovery. Pediatr Infect Dis J 2005; 24(11

Suppl): S223-6.

Drosten C, Günther S, Preiser W et al. Identification of a novel coronavirus in patients with severe acute

respiratory syndrome. N Engl J Med 2003; 348(20): 1967-1976.

Ksiazek TG, Erdman D, Goldsmith CS et al. A novel coronavirus associated with severe acute respiratory

syndrome. N Engl J Med 2003; 348(20): 1953-1966.

Peiris JS, Lai ST, Poon LL et al. Coronavirus as a possible cause of severe acute respiratory syndrome. Lancet

; 361(9366): 1319-1325.

Song HD, Tu CC, Zhang GW et al. Cross-host evolution of severe acute respiratory syndrome coronavirus in

palm civet and human. Proc Natl Acad Sci U S A 2005; 102(7): 2430-2435.

Lau SK, Woo PC, Li KS et al. Severe acute respiratory syndrome coronavirus-like virus in Chinese horseshoe

bats. Proc Natl Acad Sci U S A 2005; 102(39): 14040-14045.

Li W, Shi Z, Yu M et al. Bats are natural reservoirs of SARS-like coronaviruses. Science 2005; 310(5748):


Zaki AM, van Boheemen S, Bestebroer TM et al. Isolation of a novel coronavirus from a man with pneumonia in Saudi Arabia. N Engl J Med 2012; 367(19): 1814-1820.

Guo YR, Cao QD, Hong ZS et al. The origin, transmission and clinical therapies on coronavirus disease 2019

(COVID-19) outbreak - an update on the status. Mil Med Res 2020; 7(1): 11.

Guan Y, Zheng BJ, He YQ et al. Isolation and characterization of viruses related to the SARS

coronavirus from animals in southern China. Science 2003; 302(5643): 276-278.

Reusken CB, Raj VS, Koopmans MP et al. Cross host transmission in the emergence of MERS coronavirus.

Curr Opin Virol 2016; 16: 55-62.

Chatterjee R, Bhattacharya S. Could novel corona virus (SARS-CoV-2) be the evolving face of a new generation

of genetically complex epidemiological challenges? Malaysian J. Med Res 2020; 4(2): 49-52.

Ji W, Wang W, Zhao X et al. Cross-species transmission of the newly identified coronavirus 2019-nCoV. J Med

Virol 2020; 92(4): 433-440.

Cheng ZJ, Shan J. 2019 Novel coronavirus: where we are and what we know. Infection 2020; 48(2): 155-163.

Zheng J. SARS-CoV-2: an emerging coronavirus that causes a global threat. Int J Biol Sci 2020; 16(10): 1678-

Shi J, Wen Z, Zhong G et al. Susceptibility of ferrets, cats, dogs, and other domesticated animals to SARScoronavirus 2 [Published online ahead of print, 2020 Apr 8]. Science 2020; eabb7015.

Salata C, Calistri A, Parolin C et al. Coronaviruses: a paradigm of new emerging zoonotic diseases. Pathog

Dis 2019; 77(9): ftaa006.

Wang LF, Shi Z, Zhang S et al. Review of bats and SARS. Emerg Infect Dis 2006; 12(12):1834-1840.

Banerjee A, Kulcsar K, Misra V et al. Bats and coronaviruses. Viruses 2019; 11(1): 41.

Griffin DR. Migrations and homing in bats In Wimsatt WA (ed.) Biology of bats, Academic Press, New York,

USA. 1970; 233-264.

Calisher CH, Childs JE, Field HE et al. Bats: important reservoir hosts of emerging viruses. Clin Microbiol Rev

; 19(3): 531-545.

Yadav PD, Aich AS, Nyayanit DA et al. Detection of coronaviruses in Pteropus & Rousettus species of bats

from different States of India. Indian J Med Res 2020.

Angelsen A, Kaimowitz D. Rethinking the causes of deforestation: lessons from economic models. World

Bank Res Obs 1999; 14(1): 73-98.

Sehgal RN. Deforestation and avian infectious diseases. J Exp Biol 2010; 213(6): 955-960.

Leroy EM, Kumulungui B, Pourrut X et al. Fruit bats as reservoirs of Ebola virus. Nature 2005; 438(7068):


Afelt A, Lacroix A, Zawadzka-Pawlewska U et al.Distribution of bat-borne viruses and environment

patterns. Infect Genet Evol 2018; 58: 181-191.

Walsh MG, Wiethoelter A, Haseeb MA. The impact of human population pressure on flying fox niches and

the potential consequences for Hendra virus spillover. Sci Rep 2017; 7: 8226.

Brown C. Emerging zoonoses and pathogens of public health significance--an overview. Rev Sci Tech 2004;

(2): 435-442.

Mavroidi N. Transmission of zoonoses through immigration and tourism. Vet Ital 2008; 44(4): 651-656.

Dobson AP, Kutz S, Pascual M et al. Pathogens and parasites in a changing climate. Adv Appl Biodivers

Sci 2003; 4: 33-38.

Harvell CD, Mitchell CE, Ward JR, et al. Climate warming and disease risks for terrestrial and marine biota.

Science 2002; 296(5576): 2158–62.

Patz JA, Graczyk TK, Geller N et al. Effects of environmental change on emerging parasitic diseases.

Int J Parasitol 2000; 30(12-13): 1395-405.

Halford WP, Gebhardt BM, Carr DJ. Mechanisms of herpes simplex virus type 1 reactivation. J Virol 1996;

: 5051-5060.

Mehta SK, Cohrs RJ, Forghani B et al. Stress-induced subclinical reactivation of varicella zoster virus in

astronauts. J Med Virol 2004; 72(1): 174-179.

Morse SS. Factors in the emergence of infectious diseases. Emerg Infect Dis 1995; 1(1): 7-15.

Wang LF, Cowled C. Bats and viruses: a new frontier of emerging infectious diseases. John Wiley Sons Inc,

Hoboken, NJ, USA. 2015.

Monchatre-Leroy E, Boué F, Boucher JM et al. Identification of alpha and beta coronavirus in wildlife

species in france: bats, rodents, rabbits, and hedgehogs. Viruses 2017; 9(12): 364.

Chen W, Yan M, Yang L et al. SARS-associated coronavirus transmitted from human to pig. Emerg

Infect Dis 2005;11(3): 446-448.

Bhattacharya S. Development and disease: Interpretation of inter relationship in the context of

mosquito-borne maladies. Sci Cult 2012; 78 (1-2): 47-53.

Hueffer K, Murphy M. Rabies in Alaska, from the past to an uncertain future. Int J Circumpolar Health 2018;

(1): 1475185.

Ostfeld R, Keesing F. Biodiversity and disease risk: the case of Lyme disease. Conserv Biol 2000; 14: 722-728.

LoGiudice K, Ostfeld RS, Schmidt KA et al. The ecology of infectious disease: effects of host diversity and

community composition on Lyme disease risk. Proc Natl Acad Sci U S A 2003; 100(2): 567-571.

Wood CL, Lafferty KD. Biodiversity and disease: a synthesis of ecological perspectives on Lyme disease

transmission. Trends Ecol Evol 2013; 28(4): 239-247.

Keesing F, Holt RD, Ostfeld RS. Effects of species diversity on disease risk. Ecol Lett 2006; 9(4): 485-498.

Luis AD, Kuenzi AJ, Mills JN. Species diversity concurrently dilutes and amplifies transmission in a

zoonotic host-pathogen system through competing mechanisms. Proc Natl Acad Sci U S A 2018; 115(31):