How did COVID-19 get to a tiger? Therein hangs a tale

The news from the Bronx Zoo in New York that Nadia, a four-year-old female Malayan tiger, tested positive for novel coronavirus is shocking. It needs a thorough evaluation in the wake of the Covid-19 pandemic.

Nadia contracting the virus seems to be closely connected with the burning issues of global climatic change and unprecedented human activities for trade and commerce.

Nadia, a captive-bred big cat, lacks natural instincts found in tigers in jungles. As against wildlife, the immune system in captive-bred animals is comparatively low.

A considerable number of people in the US have fallen prey to Covid-19. The source of the virus in Nadia seems to be the zookeepers. Unlike in India, the zookeepers in the US hug and kiss the captive-bred animals. This practice strengthens the suspicion that the zookeepers may have transmitted the virus to Nadia.

The theory that viruses like the novel coronavirus normally infect wild animals as they stay away from human environs can’t be ruled out easily. Still, this virus infecting wild animals is actually hard to digest.

Such diseases are transmitted from one living organism to another while their impact may be different in different organisms. Like Ebola and SARS, the novel coronavirus has been transmitted from animals such as bats and snakes. It has been established that trees and insects cannot transmit this virus.

Unlike in the human world, the novel coronavirus doesn’t wreak havoc in wildlife due to high immunity in wild animals. Micro-organisms have always played a major role in natural selection and have shaped species and speciation in evolution.

These micro-organisms, including viruses, are all part of the ecosystem of the earth. Some are favourable to humans while some are not. The effectiveness of pathogens is limited by ecological factors as well as geographical boundaries.

When the early explorers travelled across the globe, they not only decimated indigenous peoples by the pathogens they carried with them but they also brought back to their homes many new pathogens, which had a devastating effect on both sides of the globe.

Normally, humans and wildlife evolve with their respective immunological defences. When these pathogens are transmitted from one cluster or community to another, breaking natural barriers, every life form becomes susceptible.

Viruses causing rabies and filariasis are, sometimes, detrimental to African wild dogs, lions and hyenas. Several wild animals died in India as this virus infected wolves and buffaloes in forests.

Many diseases are transmitted from domesticated animals to humans, on the one hand, and to animals in forests, on the other. Transmission can effectively happen when wild animals consume domesticated animals. Buffaloes, deer or animals that prefer to live in groups are vulnerable to transmission.

Since animals like tigers and leopards stay alone and maintain distance, transmission is hard to occur. These, actually, are zoonotic diseases that are caused by germs. They are transmitted between animals and people. A critical analysis of the entire process makes it clear that unprecedented human activities play a crucial role in spreading these diseases.

Zoonotic diseases spread primarily due to human activities. Deforestation, environmental pollution and global trade and commerce play dominant roles in spreading zoonotic diseases.

The novel coronavirus and its cascading effects have unfolded global changes, hopes and challenges. The contribution of poisonous gases by the global population is tremendous. Heavy winds and rains fuelled by these gases result in certain changes.

Uncontrolled human greed and activities are over-exploiting almost all the ecosystems of the world. Timber and non-timber forest produce, wildlife for pet markets, bush meat trade for food and traditional medicine, etc., can pick up the baggage from anywhere and transform alien pathogens across the globe to any corner of the world.

Wild animals are primary hosts for pathogens like Ebola and AIDS. These pathogens successfully found human hosts as the bush meat trade became global.

Environmental challenges

When trade and commerce are preferred over other processes, environmental challenges take a back seat, triggering global warming. These activities gift pandemics like Covid-19 to human society. With our high population density, transmission of diseases is always probable, indeed inevitable.

Almost all these are linked to global climatic change. We cannot just look at solving a small unit of the crisis that we are facing today. The unit as a node is linked to multiple entities which have to be looked at holistically.

The lockdown and subsequent standstill of human activities is quickly containing contamination in the ecosystem. Though it is interesting to ascertain the impact of this purification on forests, it is mostly impossible to assess upheavals or changes in nature due to the purification process in a short span of time

The present crisis draws attention to the two most significant factors. First, there is an urgent need to contemplate upon the causes for the contemporary crisis. Second, if we really want to tread the righteous path, then it is inevitable to seriously consider global climatic changes.

The novel coronavirus has taught the human world the biggest lesson ever: There will be devastating effects if the blind development path is preferred over the ecosystem.

The global leaders should finally learn a lesson that humans are just one part in the entire ecosystem and that every living being has an equal right to live on the earth. Leaders with a sense of responsibility and conscious of these truths will create a ray of hope.

(Krupakar-Senani are wildlife experts, conservationists and filmmakers)