COVID-19 Origin: Poor Bats Can’t Prove Their Innocence

A recent study suggests increased risk of formation of coronavirus hotspots caused due to deforestation and livestock revolution leading to zoonotic transmission of coronavirus from bats to humans. The study seems to sow enough subliminal seeds in the minds of people in support of zoonotic transmission of the novel coronavirus (SARS CoV-2), that has led to the cataclysmic COVID-19 pandemic.

Scientists have been grappling to find out the origin of SARS CoV-2 that has led to the global pandemic resulting not only in loss of millions of lives but also bringing the economy of several countries to almost a standstill. The recent Nature paper by Hayman and colleagues¹ provides a comprehensive analysis of regions in the world populated by horseshoe bats (species that are hosts to SARS related coronaviruses). The area spans over 28.5 million square km-majority of which is in China. The analysis suggests fragmentation of habitat by human intervention and settlements (increase in cropland distribution and livestock density) that has led to increased interaction between humans, livestock and wild-life (in this case bats), that may have led to the zoonotic transmission of virus from bats to humans. 

However, deforestation, agricultural use of land and urbanisation are going on since Neolithic period when humans transformed from a hunter-gatherer to settled life involving livestock revolution. The pace of urbanisation has increased drastically in the last few decades that involved further land use change to accommodate the needs of growing global population. Some amount of zoonotic transmission of pathogens from animals to humans via an intermediate species is a known knowledge anyway as was seen in SARS (bats to civets to humans) and MERS (bats to camels to humans) viruses². But, how did the SARS virus become highly virulent and transmissible to become SARS CoV-2 to infect humans without a known intermediary species found so far?  

The analysis presented by Hayman and colleagues¹ neither proves nor disproves the theory of transmission of SARS CoV-2 from bats to humans. Their analysis seems to sow enough subliminal seeds in the minds of people in support of zoonotic transmission of the novel coronavirus (SARS CoV-2), that has led to the cataclysmic COVID-19 pandemic.

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References: 

1. Rulli M C, D’Odorico P, Galli N et al. Land-use change and the livestock revolution increase the risk of zoonotic coronavirus transmission from rhinolophid bats. Nat Food (2021). https://doi.org/10.1038/s43016-021-00285-x 

2. Soni R. Did the SARS CoV-2 Virus Originate in Laboratory? Available online at https://www.scientificeuropean.co.uk/covid-19/did-the-sars-cov-2-virus-originate-in-laboratory/ 

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