In August and September this year, a team of doctors in Kozhikode was taken aback when they were faced with a mystery illness that claimed two lives and affected a few others. When a state-level surveillance was undertaken, the disease—which affected the patients’ respiratory system and, in some cases, nervous system as well—could be traced to the zoonotic Nipah virus.
The disease is known to spread from bats (reservoirs) to humans directly, or via pigs or horses (intermediate hosts), or through consumption of food contaminated with the saliva, urine, or excreta of an infected animal, or direct human-to-human transmission. Its prevention and treatment are challenging.
The recent cases in Kerala constitute a study in the evolution of zoonotic disease risk, a problem exacerbated by rapid development in ecologically sensitive areas. As more and more people around the globe live close to bats and other wildlife that host potentially harmful pathogens, transmission of these pathogens from wild animals to people is becoming more frequent, often with lethal consequences.
The disease outbreak in Kerala has shown its zoonotic underpinnings, which has emphasised the need for co-ordinated efforts at various levels. Zoonotic diseases that have the potential for human-to-human transmission spread rapidly once they latch on to a human host, Covid-19 being the most glaring example of this phenomenon.
Evidence suggests that preserving the natural habitats of hosts or reservoirs of pathogens (in this case, bats) plays an important role in preventing the spillover and spill-back of zoonotic diseases. The key is to understand the dynamics of disease emergence and spread through the human-livestock-wildlife interface and subsequently design interventions to respond efficiently.
This is where the One Health approach comes in. It calls for bringing different sectors together to address health issues, economic losses, and food security challenges. The approach has major implications for India, which has immense diversity of wildlife, one of the largest livestock populations in the world, and a high density of human population. The One Health approach recognises that the health of humans, animals, and the wider environment are closely linked and inter-dependent.
The outbreak of the Nipah virus was tackled through a spectrum of interventions by the state health department with support from the Ministry of Health and Family Welfare, the Indian Council of Medical Research, the National Institute of Virology, Pune, and the National Institute of Epidemiology, Chennai. This multi-disciplinary coordination and response highlighted the importance of the One Health approach for streamlined actions using existing resources. The approach can improve preparedness among different stakeholders across the implementation area and public awareness in containing outbreaks.
NGOs like WWF-India that have been working on biodiversity conservation for decades have been supporting wildlife monitoring and protection efforts, addressing human-wildlife conflict, securing connectivity in conservation landscapes, strengthening community stewardship for conservation action, and restoring wildlife habitats. Healthy ecosystems contribute to the overall well-being of both animals and humans, hence reducing the risk of diseases that arise at the human-animal-ecosystem interface. Thus, our efforts towards conservation of natural ecosystems are aligned with the One Health approach.
Understanding the dynamics of disease transmission at the wildlife-livestock-human interface is critical in preventing disease emergence and spread. In coordination and collaboration with the stakeholders, the One Health approach is visualised through the lens of designing interventions and integrating them with conservation actions to achieve the overall goal of improving well-being of animals and human beings, sustainable and resilient livelihoods, and biodiversity conservation.
Government authorities, along with NGOs, are conducting disease monitoring and surveillance of livestock populations in some states. Surveys are also being conducted among poultry farmers and forest department staff to gauge their awareness of zoonotic diseases like Avian Influenza and their readiness to handle disease outbreaks. Integrating One Health with wildlife conservation in forest fringe areas will require strong collaboration and a shared understanding of the interconnectedness of human, animal, and environmental health.
Dr Shelly Mittal is an Associate Coordinator in the One Health programme at WWF-India