By Invitation. Let’s be prepared for the unknown virus

Emerging infections, particularly viral diseases, have been the single largest challenge to global health security. The recent surfacing of the Nipah Virus (NiV) in Kerala is a perfect example.

It was contained with an exemplary public health response, averting a catastrophe, and gives us an opportunity to reflect on the challenges caused by unknown viral threats, besides our preparedness to deal with such emergencies.

Most emerging viruses are RNA viruses, jumping from animals to humans. The tendency of diseases to jump species dates back to the times of hunters and nomads. Nomads becoming settlers resulted in and even sustained human-to-human transmission of diseases.

But the pattern of virus jumping from animals to humans continues to evolve, and rapidly, due to increasing deforestation as part of development, unplanned urbanisation and climate change.

The rate of emergence of viral diseases has increased exponentially over the past decade, partly due to the availability of newer scientific tools for detection. Many of the recent deadly viruses such as Severe Acute Respiratory Syndrome Corona virus (SARS-CoV), Avian Influenza (Bird flu), Middle East Respiratory Syndrome Corona Virus (MERS-CoV), Nipah Virus, Hendra Virus, Hanta Virus and Ebola Virus are from animals or birds.

There is an increasing body of evidence that bats are reservoirs of emerging viral infections, such as Nipah and Ebola. Fruit-eating bat represent the biggest risk for human contact as most of the flesh of fruit is discarded from the mouth of the feeding bat, giving ample opportunity for virus spread. And the proximity of human habitats to that of the bats and poor hygiene practices result in the flaring up of transmission.

Murine rodents (relating to or affecting mice or related rodents) are one of the most successful animals in evolution and widely distributed in all continents. They are the natural hosts for a variety of arenaviruses and hantaviruses. Climate and environmental changes have an impact on their reproductive cycle. And again, they live in close proximity to humans and consume at least a fifth of the world’s grain, ensuring conducive conditions for virus transmission to humans.

Pigs are associated with viral outbreaks, like in Japanese Encephalitis, Nipah and Ebola Ruston viruses. They are also susceptible to both human, avian and swine influenza viruses and act as a mixing pot for emergence of influenza viruses with pandemic potential. As economic ventures like pig farming take centre stage, the focus on public health and hygiene also needs to assume a larger role. The situation is compounded by the ease of travel, particularly air travel, a major cause for the global spread of viruses as any infectious disease can reach any part of the globe in just 36 hours. Hence, to expect the unexpected, we need to be prepared. Many of the viruses, including Zika, were first discovered during the extensive exploratory animal surveillance in African forests and elsewhere through The Rockefeller Foundation, following World War II.

Generating a database

So the need of the hour is to conduct nation-wide, well-planned and coordinated animal and vector surveys to identify possible viruses they are hosting — using advanced technology such as next generation sequencing and multiplex serosurvey. This will help India generate the database of potential viruses that may emerge in the coming days, and prepare for their early detection if they emerge. Further, we need to promote disease surveillance on a one-health platform with enhanced laboratory capacity built into the existing revamped Integrated Disease Surveillance Programme (IDSP). Promoting the culture of laboratory confirmation of diseases at lower-level hospitals can help detect unusual disease clusters.

Today, an outbreak of an unusual virus or an emerging disease can take a country hostage. It can interrupt the economy of the country and threaten to derail international relations. Hence, an investment in public health and hygiene to anticipate and be prepared for a potential viral disease is not just justified. It is an absolute public health necessity.

Arunkumar Govindakarnavar h eads the Manipal Centre for Virus Research, Manipal Academy of Higher Education. Views are personal

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