Evicting the Encroachers – The Battle against Zoonoses in India

The hunt for the missing piece in the puzzle is underway with epidemiologists, health authorities and virologists still looking for the ambiguity in the man and animal  connection that is leading to episodes of outbreaks of zoonotic infections. Zoonotic infections can have lethal implications leading to rising mortality rates and economic losses for the country. Recurring outbreaks in recent times have created an air of uncertainty around the exact cause of human transmission.

By Sonali Patranabish

Zoonoses has become a huge public health challenge in India, equally putting at risk both human and animal health. Rampant cases of zoonotic outbreaks in recent times highlight the urgent need for surveillance to curtail further outbreaks and deaths that ensue. India currently finds itself positioned in a vulnerable state according to the numbers that were released by the National Center for Disease Control (NCDC).

The number of lab-confirmed cases has doubled since 2018, which stands at 388 lab-confirmed zoonotic cases as of 2023. Zoonotic diseases like Japanese encephalitis, Leptospirosis, Nipah virus, Zika virus, Scrub typhus, Brucellosis, and West Nile virus are being increasingly reported year on year. While few of these are endemic zoonoses, Nipah virus, Zika virus, CCHF (Crimean-Congo Haemorrhagic fever) and KFD virus ( Kyasanur Forest disease) have raised concerns amongst officials, as they have been categorized as emerging diseases.

Key Initiatives - To Nab the Enemy

The rising number of zoonoses cases as well as emerging infections sounds a clarion call to all stakeholders in the healthcare sector and policymakers to nail the root cause of such deadly infectious diseases that are claiming the lives of many. Prevention and preparedness will have to be the core focus to gun down this menace. Creating a comprehensive blueprint that involves collective efforts of multiple sectors and a multidisciplinary approach is the key to combating the surge in zoonotic diseases.

“A key initiative should be the implementation of a One Health approach, integrating human, animal, and environmental health to prevent spillovers from animal reservoirs to humans,” opines Dr Muhammed Niyas VK, Consultant, Infectious Diseases, KIMSHEALTH Trivandrum.

Dr R Gopakumar, Senior Consultant and HOD, Internal Medicine, Apollo Adlux Hospital, Ernakulam states, "Timely initiatives are crucial for tackling these challenges effectively. Strengthening surveillance and monitoring systems, intensifying public awareness campaigns on disease prevention, and upgrading healthcare infrastructure—especially in rural areas—are essential steps."

Dr Swati Rajagopal - Consultant - Infectious Disease and Travel Medicine, Aster CMI Hospital, Bangalore shares that the impact of the COVID-19 pandemic is a reminder of the need to brace ourselves up to ensure that we have effective zoonotic disease control measures in place.

She further adds, "Improving early detection and surveillance systems is critical to identify potential zoonotic threats as soon as possible.”

She highlights that strengthening biosecurity measures in animal markets, farms, and wildlife habitats and interdisciplinary collaboration between human health, animal health, and environmental sectors is vital to reducing disease transmission risk.

Moving over from reactive to proactive

A proactive approach is needed to address the challenges to ensure improved public health outcomes w.r.t combatting zoonotic infections. Containing the spread of such infectious diseases in the early phases is crucial to curtailing further outbreaks. Such outbreaks are known to have an overbearing effect on the economy as well. In lieu of the cascading effects of such emerging zoonoses, collective and concerted efforts of governments, private entities, and policymakers are a critical loophole to nab this menace.

Dr Rajagopal suggests that individual accountability and consciousness in the form of maintaining good hygiene, vaccination of pet animals, protecting against vectors and staying informed are a few of the essential steps towards preventing zoonotic diseases.

Individual accountability and consciousness are the first steps in preventing zoonotic diseases.

As the age-old adage goes, prevention is better than cure, Dr Rajagopal further implies this by saying that awareness of disease transmission mechanisms and lessons learnt from previous outbreaks is the key to safeguarding our societies from further outbreaks.

Dr Gopakumar opines, “Healthcare preparedness is critical, involving specialised training for healthcare workers, public awareness campaigns, and ensuring hospitals are well-stocked with essential medical supplies.”

He further goes on, "Preparedness measures should be proactive and comprehensive, incorporating the establishment of specialized zoonotic disease control units, conducting regular practice drills and mock scenarios, and maintaining an updated inventory of necessary vaccines and medical supplies.”

Dr Anup Warrier, Group Chief of Medical Affairs, Aster DM Healthcare India stresses the awareness of care definitions among clinicians i.e. crucial signs that one should suspect in an emerging infectious disease.

Dr Warrier adds a few other essential practices to ensure the preparedness of the healthcare system, like SOPs on testing protocols that ensure ease of logistics, empowering private labs to perform testing under regulatory guidelines and supervision and accreditation bodies like NABH and JCI should ensure hospitals are well equipped to face such outbreaks.

Modus operandi - Groundwork

Given the complex interplay of various risk factors like socio-economic, genetic, anthropogenic, and genetic factors, surveillance needs to top the list when a blueprint or roadmap is being charted out to limit the spread of zoonoses. Strengthening surveillance, promoting data sharing, enhancing laboratory testing capabilities, and fostering joint outbreak responses in both the human and animal health sectors will establish the necessary infrastructure to effectively prevent, predict, detect, and respond to emerging health threats, thereby reinforcing global health security.

Dr Rajagopal suggests a few key strategies to contain disease outbreaks, detecting zoonotic diseases early on, launching public awareness campaigns to inform people about the dangers of zoonotic infections, and strengthening cooperation between the veterinary and public health sectors.

She reiterates the need for improved sanitation for both rural and urban regions and supports research projects aimed at understanding the dynamics of zoonotic disease transmission.

Dr Muhammed adds that decentralised molecular diagnostic capabilities, including sequencing technologies, are crucial.

“Currently, molecular testing and sequencing are concentrated in a few national labs, which can delay outbreak response. Decentralising these services to state-level laboratories would facilitate faster, more precise detection and tracking of zoonotic pathogens and their variants,” opines Dr Muhammed.

Dr Warrier uses a root cause approach to address the risk factors and create a roadmap based on this. He opines, “Addressing the larger issues of global warming/climate change and its impact on animal ecosystems, review of government policies of expansions of human habitation that encroaches upon and increases the human-animal interface has to be thought of.”

He further adds that arboviral diseases (spread through insects like mosquitoes) have to be addressed through a strong focus on solid and liquid waste management - especially in urban areas.

Breaking all barriers: Extensive experimentation and exploration

Research and development activities are underway w.r.t vaccine development for emerging viruses.

The University of Oxford is currently undertaking human clinical trials for the Nipah virus vaccine. India is currently awaiting human clinical trials of the novel Nipah monoclonal antibody which can afford immediate protection against infection. Funded by the Coalition for Epidemic Preparedness Innovations (CEPI), the human trials are awaiting approval and are expected to commence by 2025.

In a recent development, Indian Immunologicals Limited (IIL) has signed an MoA with the Indian Council of Medical Research (ICMR) for the clinical development of India's first codon-deoptimised Zika virus vaccine.

While IIL will be working on the vaccine front, other researchers like Dr Rajanish Giri (Assistant Professor) IIT Mandi have worked on studying the Zika virus proteome. His innovative ideas on Zika virus capsid enfolding and inhibitor discovery will help fetch better insights into the entry of the virus and help with drug development.

Dr Warrier states, “Special methodologies of developing clinical evidence through global networking and performance of multi-centric randomised control trials in treatment strategies and accelerated development of effective vaccines hold the hope for future.”

He further adds, “A fully integrated and connected laboratory system (public and private) that is available for the general public to review the cases reported in real-time (as these are 'notifiable' diseases) will improve the public awareness and clinician preparedness based on this surveillance data.”

Several studies are also underway w.r.t Chandipura virus, transmitted through sand flies and mosquitoes. Studies are currently being carried out with mosquito cell lines to enable to early detection. Efforts are in progress to develop a vaccine for the virus, as per reports of two candidate vaccines are currently under development.

Virologists at the Banaras Hindu University are researching the pathogenic processes of the virus that will provide them with crucial information enabling diagnosis and drug development.

Foundation for Neglected Disease Research (FNDR) and Spanish firm DevsHealth have partnered on a collaborative project to develop broad-spectrum antiviral agents for zoonotic infections caused by flaviviruses such as dengue, Zika, West Nile virus, and Japanese encephalitis.

Outlook

The complexity of disease dynamics, multiple risk factors, tracing contact transmission and lack of awareness are a few of the on-ground difficulties while dealing with emerging zoonotic diseases.

“The gaps and limitations in our understanding of zoonotic illnesses have increased the number of cases and outbreaks,” opines Dr Rajagopal. She further states that thorough research on risk factors and modes of transmission must be initiated.

“Despite the vast amount of data generated annually on zoonotic diseases in both sectors, there is minimal coordination and sharing of this crucial information between human and animal health agencies. This lack of collaboration leads to inefficiencies in controlling zoonotic outbreaks. The issue is not just about breaking the silos but fostering effective communication between them,” opines Dr Narayanan SB, Joint Secretary, Indian Veterinary Association Kerala.

Dr Narayanan further goes on to suggest and opines, "A well-coordinated 'One Health approach, which integrates efforts across human, animal, and environmental health, is essential for managing zoonotic diseases in a timely and effective manner, reducing the gaps and cracks that allow outbreaks to persist.”

In alignment with Dr Rajagopal’s statement, "Dr Warrier states that the war on zoonoses will require to dive deep into lacunae and loopholes, especially about lack of adequate training/exposure in clinical case definitions lead to missing of cases, lack of access to easy laboratory testing often dissuades the clinician to take up the efforts to test and identity, communication of the disease manifestations, and difficulty in logistics of lab testing through solely government sources are also barriers.

“Since the two major background reasons for emerging infectious diseases are global warming and increased man-animal interfaces (due to widening of human habitation), a big picture view on these would also help,” opines Dr Warrier.