Veterinarian response to the COVID-19 crisis : Animal health

Dr K Rashbehari Singh
The Coronaviruses have characteristic ‘corona’ (crown) of spike proteins which surround their lipid envelope, and hence called coronaviruses. Coronavirus (CoV) infections are common in both animals and humans and some coronavirus strains can cause zoonotic diseases (infectious diseases that can be transmitted between humans and animals). Coronaviruses can cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (caused by MERS-CoV) and Severe Acute Respiratory Syndrome (caused by SARS-CoV) in humans. It was demonstrated that MARS-CoV and SARS-CoV viruses were transmitted to humans from dromedary camels and civets respectively.
A novel coronavirus  disease  2019 (COVID-19), classified as zoonotic disease,  caused by  Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2 ) was identified from humans in Wuhan, China in 2019 and quickly led to a global pandemic and has subsequently devastated economies and healthcare systems worldwide.
Covid-19 is a new infection and time is the key to understand how it will evolve.   As per WHO report (2006), about 61 per cent of human pathogens are zoonotic in origin, while zoonoses account for a whopping 80 percent of the global emerging diseases in humans in the past three decades. COVID-19 is a zoonotic disease, originated from animals, jumped to humans, and spread by person to person transmission.
WILDLIFE VIRAL SURVEILLANCE
Through the years veterinary epidemiologists and virologists have been dealing with the circulation of pathogenic viruses among wild animals. Studies on the virus evolution, spread and pathogenesis in domestic and wild animals provided essential inputs for the integrated surveillance studies on the etiology of viral zoonoses and their impact on the health of animals, humans, and the ecosystem.
Coronaviruses appear to have origins in a variety of bat species and, to date, over 200 novel coronaviruses have been identified in bats. But they need intermediate hosts   before jumping to humans. Indeed, coronaviruses are very keen to jump species barriers (inter-species transmission), to evolve, and to find new ecological niches. This spill-over was confirmed for SARS-CoV and MARS-CoV, with masked palm civets and dromedary camels as an intermediate host, respectively. However, the zoonotic source of SARS-CoV-2 remains unidentified to date. The surveillance of coronavirus in wild life, notably in hot spots marked by risky human-animal interfaces, need to be integrated with human medicine with the aim to advance interdisciplinary research studies,  to understand and predict potential spill-over phenomena and to prevent or limit future human pandemics.
VETERINARIANS AND ANIMAL INFECTIOUS EPIDEMICS
Veterinarians have gained extensive field experience in the control of past epidemics of infectious and contagious diseases of animals and zoonotic diseases, transmissible from animals to humans. Veterinary epidemiologists have successfully applied a variety of surveillance methods to understand the ways in which viral agents spread, and to support evidence-based, effective, sustainable and timely measures for the reduction of the level of prevalence or the elimination of infectious diseases in animal populations.
The human health system, traditionally, focuses on the treatment of the individual patients and rarely the measures are directed to the whole population. In veterinary medicine, on the contrary, the health control strategy is directed to the whole animal population (e.g. livestock and poultry), since epizootic diseases cause high costs for general agriculture and livestock sectors, though with limited risk to public health.
Controlling an infectious outbreak requires understanding of the nature, scale, and dynamics of the epidemic, with the aim to reduce the disease prevalence and to provide swift evidence to the decision-makers for implementing measures able to mitigate the economic and animal health burden.
Considering the experience gained by the veterinarians in the epidemiology of animal diseases within populations, using active and passive surveillance systems and risk analysis, veterinary medicine might provide a valuable contribution of knowledge to public health for the control of infection in the human population. (To be contd)