Environmental Norms for Zoonotic Diseases

  Reasons for shift of diseases from Wild to Man

  Zoonotic Disease

Diseases that have jumped from animals to humans are known as Zoonotic diseases and the process is called Zoonosis

It is derived from the word Zoo means animal and nosis means disease

Intimate and prolong contact between man and animal facilitates the transmission of various communicable diseases between them and then they becomes a part of human system and surroundings

Examples – Nipah, HIV, Ebola, Zika, SARS, MERS, bird flu and COVID-19

High-risk individuals: pregnant women, adults aged 65 or older, children 5 years old or younger, people with a weak immune system

As we all know about the past trend of jumping of these diseases from animal to human, its high time to understand the underlying cause of the problem. Mobilising human and financial resources can not help us in eradicating the problem.

Approach to Deal: bringing together experts from multi disciplines i.e. human-animal-plant health and the environment. Understanding one component can not help in solving the problem.

  CORONA – a wake up Call

Corona is a wake-up call asking us to think again seriously about the human-nature relationship

Humans are root drivers of such pandemics - growing food demands for agriculture and livestock needs more and more of land which is coming from the destruction of wild habitat. We are paying huge hidden cost of so-called economic development

Habitat destruction by human and interferences in the wild leads to more of man and wild interaction and spread of the animal virus to human

It is believed that SARS-CoV-2 is a bat-origin virus (horseshoe bat) with  96.2 per cent genetic similarity

Bats are a natural unique reservoir of many viruses. The body of bat has a natural immunity to these viruses, but when they jump to the human they suffer as the body has no mechanism and antibodies to fight this animal virus.


  Reasons for shift of diseases from Wild to Man

The major reason for zoonotic diseases is close contact between man and wild. This could be eating them, being in close proximity, contamination by their droppings and food half consumed by them (example fruits half consumed by bats). 

Destruction of wild habitat forces the animal to move near to human settlements in search of food

Wet market (for example Wuhan in China) can be the main source of disease transmission. Not just China but also bush meat stall in Africa, Indonesia, and also in North-east India can become this source if not regulated.

Apart from the wet market the trade of wild animals also creates similar favourable conditions for the spread of zoonotic diseases. Even after mutual agreements nationally and internationally the illegal poaching and trade of wild animals are rampant in many countries.

Out of 335 diseases emerged between 1960-2004; 60% came from animals (Emerging Infectious Disease, 2017)







  Transmission from Wild to Man

The transmission of disease from wild to man has been illustrated in the diagram given below. The primary host for the virus is the body of a wild animal. The virus can get into the human body by various ways of close contact (discussed previously). The virus then decides and reproduce in the human host. As their number grows human body tries to fight back which causes inflammation in the lungs and difficulty in breathing.

The close contact of an infected person then spread the disease in other people. Therefore, social distancing is considered to be a key weapon to fight this disease.

  Environmental Factors and Diseases

Air pollution can worsen the situation cause respiratory illness makes people prone to infections like COVID – 19. The probability of death due to SARS was twice in people who breathed dirtier air.

Climate change is also indirectly affecting the spread of disease from wild to man. One reason being the virus or any vector always looks for a healthy host (in the form of human) and another being the favourable climatic conditions for the vector. More and more of forest fires and forest diversion affects the animals in many ways. 

Habitat destruction causes Forest spillover of diseases. The overlap in wild and man habitat increases the risk of transmission. Monkey fever and Ebola are some examples of such diseases.

Rare becoming possible

COVID- 19 has also reported a rare event of mutation.  Virus mutate and adapt in its secondary host i.e. human system 

  Environmental Norms for Safety

  • A global effort to identify emerging strains (viruses in wildlife) that could likely emerge in the future (active surveillance)
  • Climate Change can further exacerbate the situation, thus Sincere commitments on climate change
    • by pushing animal populations to move into different areas
    • by compromising the health of animals through a reduced range of habitat 
    • Increasing population density of human and animals
  • Permanent Ban on wet markets
  • Stringent norms on wildlife trade
  • Healthy and sustainable lifestyle with no-wildlife in plate
  • Strict norms for treating bio-medical waste otherwise the situation can worsen
  • Proper management and treatment of pharmaceutical residue
  • Safe management of domestic hazardous waste i.e. Disposable masks, gloves, tissue, and other contaminated domestic waste which generally go to Municipal Solid Waste
  • Safe disposal and strict management of wastewater as the virus can survive in wastewater
  • Online air quality monitoring as it affects the immunity to resist the infection
  • Overall Harmony with nature to co-exist

What we are looking for today can be just the tip of the iceberg and many such pandemics can originate in the future. We need to get future-ready to stop such Pandemics.

Plans to protect air and water, wilderness and wildlife are in fact plans to protect man.”       Stewart Udall