[Interview] Rumours linking livestock to COVID-19 unfounded, says expert

The novel coronavirus disease (COVID-19) pandemic is believed to be a zoonotic disease, meaning it probably originated from an animal source. The associated lockdown continues to alter daily lives, including food consumption choices, shaped by several factors. Among these are rumours linking livestock to the outbreak.

Researchers have reported that there is no evidence that the novel coronavirus SARS-CoV-2, responsible for the COVID-19 pandemic, infects pigs or other livestock. However, the pandemic’s impacts will necessitate upping the ante on necessary biosecurity infrastructure in commercial livestock farms and proper cleanliness and hygiene in smallholder farms and throughout the informal value chains.

While the race is on to track the animal origin and transmission of the outbreak and its transmission pathway, scientists stress that interaction of humans or livestock with wildlife exposes them to the risk of spillover of potential pathogens. For many zoonoses, livestock could serve as an “epidemiological bridge” between wildlife and human infections.

In an interview with Mongabay-India, Ram Pratim Deka, International Livestock Research Institute’s (ILRI) main scientist in northeast India, debunks rumours swirling around livestock and COVID-19 and how uniquely placed northeast India’s livestock sector is to address challenges of zoonotic pandemics and human-triggered climate change in safe, environmentally sustainable and affordable ways.

Ram Pratim Deka discusses concerns for zoonoses in northeast India, livestock disease surveillance, transboundary issues, strengthening the livestock sector to reduce the demand for bushmeat (meat of wild animals) and ramping up the biosecurity infrastructure in commercial farms and proper cleanliness and hygiene in smallholder farms and in fresh livestock product market (wet markets) in a post-COVID world.

He says as more than 95 percent of food of animal origin comes through informal market/wet market in the region, testing of such food should be a new norm in disease surveillance. The northeast region of India lies in the Himalayas and Indo-Burma biodiversity hotspots, bordering several countries. The association between people, livestock and wild animals and birds, is a close one here.

Almost 90 percent of the rural households in northeast India keep livestock of one species or the other. The region has and will continue to exhibit a relatively high demand for meat and meat products, he said, observing that more than 90 percent of the population here eats meat.

While research has emerged connecting COVID-19 to animal origins, are there concerns for people involved in livestock management in India?

Coronaviruses are a large family of viruses that cause illnesses ranging from epidemic diarrhoea in pigs, to the common cold in people. Some coronaviruses spread only in animals, some only in people and some are zoonotic, that means they can transfer from animals to human or vice versa. The virus, SARS-CoV-2, responsible for COVID-19 is reported to be originated from bats (perhaps via another animal), but now it spreads from person to person.

There is no research evidence that the novel coronavirus can transmit from livestock species to humans. Preliminary research even suggests that poultry and pigs are not susceptible to COVID-19. Therefore, people involved in livestock management in India need not worry about COVID-19 in livestock, other than following good hygienic practices that they should always do in livestock management, handling, and consumption of livestock products.

Of course, people who deal with pets, particularly with cats, may follow COVID-19 related advisories in dealing with cats as cat and tiger are found to be susceptible to SARS Cov-2. However, even in this case, cat infections seem incredibly rare with only a few cases found in the whole world. In all of these, people spread the virus to cats and there are no cases where cats infected people. And cats often have an important role in killing pests that spread disease and eat human food, so those who keep cats should still do this, at least unless more information comes that they are a risk.

Why is zoonotic disease surveillance particularly crucial for northeast India? What are the major concerns regarding livestock (foods of animal origin) and zoonosis in the region? What are the key livestock animals in the region?

Surveillance of zoonotic diseases is crucial in northeast India because of the close association of people and animals in the region that is mainly influenced by the smaller herd size of livestock, socio-cultural beliefs, smaller landholding and hilly terrain (in most part of the region).

The region is also considered as a biodiversity hotspot and interaction among livestock species and wild birds and animals is more common more particularly in the fringe areas of reserved forest, wildlife sanctuaries etc. Some of the tribal people in hilly states also consume dogs and few species of wild animals, which could increase the risk of spillover of diseases from animals.

In addition, livestock product markets are largely informal in nature, which can increase the risk of foodborne and zoonotic diseases (e.g. cysticercosis, brucellosis) as inspection and hygiene measures are not always good. Further, some of the people sell diseased animals/animals under treatment in the market that add to the risk of transmission of diseases.

All these, make northeast India more prone to foodborne and zoonotic diseases. Moreover, there is inadequate veterinary and diagnostic infrastructure and manpower in the region that makes it difficult to take adequate preventive measures (e.g. vaccination and deworming), disease reporting, diagnosis and treatment. Therefore, close disease surveillance is quite critical to prevent foodborne and zoonotic diseases (both emerging and re-emerging) in the region.

The key livestock species available in the region are cattle, pigs, poultry and goat (mainly in Assam).

What are the major zoonotic diseases that you see in northeast India, are there any emerging and re-emerging diseases? What are the transboundary linkages?

The major zoonotic diseases that are circulating in northeast India include Japanese encephalitis, tuberculosis, brucellosis, leptospirosis, salmonellosis, Q-fever, rabies, anthrax, cysticercosis, bird flu, etc. Of these, Japanese encephalitis is re-emerging and takes many lives every year, more particularly during each summer/monsoon season.

Northeast India shares an international border with Bangladesh, Myanmar, China, and Bhutan across which a lot of informal trading/smuggling of livestock and livestock products takes place, posing a risk of occurrences of transboundary diseases.

The known transboundary diseases (in livestock) in recent years include Porcine Respiratory and Reproductive Syndrome (PRRS) in pigs that are reported to be transmitted to northeast India from south-east Asia through Myanmar. Another emerging threat of transboundary disease in northeast India is African Swine Fever (ASF) that may transmit from Myanmar. Fortunately, these are not of zoonotic nature.

How can the northeast region play an important role in preventing future outbreaks?

Emergence and re-emergence of SARS, MERS, Ebola, bird-flue, swine flu etc. in the last couple of decades indicate that COVID-19 is not the end of the threat of zoonotic diseases to mankind but many more may come in future possibly because of changes in climate, habitation, food habits, human-animal interactions and so on and therefore like the rest of the world, northeast India also needs to position itself to deal with such diseases. In our fight against diseases in the future, another major challenge is the resistance being developed by humans and animals against various antimicrobials that will limit our actions against various microbes.

Under the given challenges, northeast can reduce the chances of occurrence of future outbreaks of zoonotic disease by proper surveillance, disease reporting and forecasting of animal diseases in livestock, pet animals and beyond and taking appropriate measures to address these in a time-bound manner. To keep an eye on the transmission of diseases from wild birds and animals to humans, the disease surveillance programme should especially emphasise on fringe areas of forest/ wildlife sanctuaries and in the market where products of animal origin (especially wild, if any) are traded. In this endeavour, the forest department and environmental professionals should also be roped in.

In addition, as more than 95 percent of food of animal origin comes through the informal market/wet market in the region, testing of such food should be a new norm under the disease surveillance programme. It should be beyond the scope of testing done by the Food Safety Officers for regulatory purposes. To make a specific and focused investigation on any emerging/ re-emerging foodborne or zoonotic disease, well designed epidemiological studies should also be conducted in order to identify the risk factors and to assess the impact of the disease on life, livelihood, and economics and to recommend future courses of action.

What areas need to be bolstered to check disease outbreaks? Are there specific animal species that need to be observed with greater stringency?

Northeast India needs to gear up to strengthen its laboratory infrastructure, manpower, resources and capacities to keep a strong vigil on foodborne and zoonotic diseases including transboundary diseases. Besides, animal husbandry department, public health services department, forest department and municipal corporation/town committee should also join hands together under the spirit of ‘One Health‘ in order to address the problem of common interest.

To make this happen, there is a need for strong administrative and political will, otherwise, every department/university/research institute would continue to work in isolation which may jeopardise the required collective initiative.

In addition to disease surveillance and reporting, each state government in northeast India should have a mechanism to act quickly and decisively as suggested by such studies/investigations. Also, each state should focus on controlling the prevailing disease by way of mass vaccination and deworming. Awareness and capacity building of each value chain actor on good clean and hygiene practices that they should always follow in production, handling, marketing and consumption of livestock products is critical to prevent diseases.

Therefore, northeast states should develop a customised training course for each value chain actor and build their capacity through a systematic process of training, monitoring and certification in order to ensure the adoption of good practices.
Among the livestock species, dairy animals and pigs need to be kept under strong vigil to control most prevalent zoonotic diseases in the northeast as more zoonotic diseases prevailing in the region are associated with both the species.

How can the issue of bushmeat sale be tackled sensitively to prevent disease spillovers and at the same time ensure livelihood security of communities?

ILRI is not in the right position to advise on this as the local/national government would work as per their prevailing policies and practices. However, in order to reduce the demand for bushmeat, it is important to strengthen the livestock sector so that animal-sourced food security can be sustained. In addition, it is important to generate awareness among market actors and consumers about the health risk associated with the production, handling, marketing and consumption of meat of unnatural source.

In a post-COVID scenario, what are the major changes that need to be brought in livestock management and disease surveillance?

Post COVID-19, some of the important practices that farmers and other value chain actors should follow include proper biosecurity infrastructure in commercial farms, use of quarantine system for all newly introduced and diseased animals, proper disposal of farm waste/dead carcass/aborted materials, restriction of entry of visitors to livestock farms and prevent the entry of rodents, wild birds and animals.

In addition, following better hygienic measures in livestock production, product handling, marketing and consumption, use of personal protective clothing (e.g mask, gloves, apron, gumboot/shoe cover etc.) in livestock farms and livestock product marketing, and following good antimicrobial and pesticides use practices, among others will be important.

All these have already been included in our customised training manuals, protocols and SoPs that we have developed to train all the market actors involved in dairy and pork value chains for improved control of foodborne zoonotic diseases under the World Bank-sponsored APART [Assam Agribusiness and Rural Transformation Project] in Assam. The same materials may also be useful for other states in the northeast region and beyond.

In addition, we are also supporting the Assam government to strengthen their laboratory capacities to conduct milk and pork safety tests with special focus on assessing foodborne and zoonotic diseases under the APART project. Further, ILRI and Assam government are finalising another MoU to support the Animal Husbandry and Veterinary Department in strengthening the disease diagnostic capacities and on conducting epidemiological studies.

Post COVID-19, there is a need for a mechanism for sharing information and taking collective action by all relevant departments, research organisations and universities associated with animal health, human health and environmental health in regards to foodborne and zoonotic diseases. There may also be allocation of a special fund for investigation of any such disease at the quickest possible time in future. COVID-19 experience also suggests that time is a critical factor in addressing such disease, therefore disease reporting systems must be very prompt and effective.

Creation of a brigade of community-level animal health workers in all the northeast states could be an extended wing of the veterinary department for disease monitoring and reporting from hilly terrain and remote rural areas.

What is the one rumour surrounding COVID-19 and animal health that you would want to debunk?

There is a rumour that broiler (chicken) can transmit COVID-19 owing to which many people have stopped consumption of broiler. There is no scientific evidence that SARS-CoV-2 virus that causes COVID-19 can transmit from broilers or any other livestock to humans. I suggest people consume livestock products as usual by following good hygiene and cooking practices. Consumption of healthy food will help people to maintain good health that may generate a better immune response against COVID-19.

Banner image: Herding bulls in Nagaland, India. Photo by ILRI.