The Nipah virus outbreak in Kerala in 2018 was, in retrospect, the first true outbreak people had witnessed in living memory. For a population fed, on screen, with pacy narratives, dizzying tales of disease, horror and death, the 2018 Nipah virus (NiV) outbreak was a horrifying reel-to-real conversion. In the latest outbreak in Kozhikode, six have tested positive and two died. NiV, with its periodic outbreaks in Kerala (fourth, now), has come to symbolise the fear and paralysis that encircle emerging diseases in modern times.
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A zoonotic disease that jumped from animals to humans as a consequence of a ‘zoonotic spillover’, NiV underlines the fact that anthropogenic causes are driving the new pandemics of the world. As these diseases emerge with stunning regularity, with their power to disrupt life, and alter the social fabric, it is incumbent upon those who rule, and those who heal, to acknowledge the dramatically changing disease factors, and the need to address health care more holistically.
‘Nipah’ comes from the Malaysian village where the first such outbreak was reported in 1998. There were reportedly over 250 cases among farm and workers in slaughter houses. Sayantan Banerjee et al record in Intractable Rare Disease Research, in 2019, that initially encephalitis-like symptoms came to notice, but doctors soon discovered that apart from the neurological manifestations, there was acute respiratory distress syndrome and respiratory failure with multi-organ dysfunction syndrome. Slowly, the world learnt of this new strain of disease where the pathogen was a paramyxovirus, and the vectors included pigs and fruit bats. Since then, India has seen several outbreaks of NiV, mainly in Kerala (2018, 2019, 2021 and 2023), but also in Siliguri in 2001, and a relatively small outbreak in 2007 in Nadia, West Bengal.
No licensed treatment
The closest reservoirs of infection in Kerala are fruit bats, and it is believed that consumption of fruits or berries contaminated with bat spittle might have caused the outbreaks. In other areas — Bangladesh and West Bengal — the consumption of date palm sap, again contaminated by bats, was behind the outbreaks. As far as therapy goes, the Centers for Disease Control and Prevention notes that currently there are no licensed treatments available for the NiV infection. Treatment is limited to supportive care, including rest, hydration and treatment of symptoms as they occur. A few doctors have reported that the anti-viral, Favipiravir, has some activity against NiV. The m102.4 monoclonal antibody is under development and evaluation.
It was when NiV hit Kozhikode district, in Kerala, in 2018, where 21 of 23 persons infected died, that the attention of not merely the health system, but also the public in general was willy nilly drawn towards the virus. Notably, Kerala’s handling of the outbreak also provided solid lessons for public health emergencies — isolating patients, contact tracing, quarantining, triaging, implementing infection control protocols, etc.
Human-to-human transmission turned out to be how Patient Zero — Mohammed Salih — of Perambra in Kozhikode contracted his infection. His brother had died just the previous week, and had had similar symptoms. Health care workers were also affected, even in the recent outbreak, so it can be transmitted via the nosocomial route too. The high mortality rates, along with the risk to health care workers and plausible multimodal transmission, emerged as causes for concern.
It is clear now that a piecemeal handling of the particular outbreak will not do. Larger factors are at play, and a more comprehensive approach towards health care itself is needed. Nations must be cognisant that anthropogenic activity, in terms of rapidly expanding agricultural fields, and destruction of the original habitats of wild animals, and overall pan-seasonal changes wrought by climate change are contributory factors. Increasingly, the One Health approach is being advocated. According to the WHO, ‘One Health’ is an integrated, unifying approach to balance and optimise the health of people, animals and the environment. It is key to prevent, predict, detect and respond to health threats.
Ideally, it involves mobilising multiple sectors, disciplines and communities at varying levels of society to work together to address root causes and create long-term, sustainable solutions. One Health involves the public health, veterinary, and environmental sectors, and is particularly relevant for control of zoonoses.
