Context: The recent rapid spread of the SARS-CoV-2 virus across the world has focused attention on the invisible processes that help pathogens originally found in wild animals, infect the humans.

Diseases of animal origin: Examples are Ebola, HIV, Severe Acute Respiratory Syndrome, Middle East Respiratory Syndrome, bird flu and swine flu. 

Underlying factors for the origin of COVID-19 like animal diseases:

  • The destruction of forests and trapping or farming of wild species has brought these animals closer to humans.
  • The viruses they harbour find ready hosts in domestic animals, moving to humans.
  • Rising activity:  such as road building and mining cutting through forests bring more people in close contact with animals. 
  • Global trade in wild species: for instance in Wuhan the trade ranges from wolf pups to rats, civets and foxes,  etc. and their sale in markets along with domestic animals.

Consequences of such pandemics: 

  • Unlike previous epidemics, COVID-19 has extracted a staggering toll, killing people, forcing a lockdown.
  • Economic devastation and recession. 
  • Short-term high growth trajectories can come to an abrupt halt with a pandemic.

What does these pandemics signify?

  • Maintain viable ecosystems: For instance, Nipah and Hendra viruses, involving transfer from bats to pigs in the former, and bats to horses, highlights the need of maintaining an ecosystem.
    • Eliminate the need for wild animals like bats to colonise human surroundings.
  • Conserve the biodiversity: Biodiversity in forests harmlessly retains dangerous viruses and other pathogens away from people. 
    • Stop viewing undisturbed landscapes as an impediment to economic growth.
  • Warning to hasty development process: hasty permissions granted for new roads, dams, mines and power projects in already enfeebled forests can unleash more scourges. 

Forest should be left undisturbed. Pristine forests with diverse species keep viruses virtually bottled up, out of man’s way.

Zoonotic diseases

Zoonotic diseases are an infectious disease caused by bacteria, viruses, or parasites that spread from non-human animals (usually vertebrates) to humans.

Modes of transmission:

  • Direct zoonosis: the disease is directly transmitted from other animals to humans through media such as air (influenza) or through bites and saliva (rabies).
  • Indirect zoonosis: transmission can also occur via an intermediate species (referred to as a vector), which carry the disease pathogen without getting infected. 

Examples of Zoonotic diseases: HIV, Ebola, Swine flu, Covid- 19 etc


Image Source: