Nipah Virus Outbreaks in India: Epidemiological Insights, Response Measures, and the One Health Perspective

Background:
Nipah virus (NiV) remains a major zoonotic threat due to its high mortality and potential for rapid spread. Since its first detection in India in 2001, outbreaks have recurred intermittently, with Kerala emerging as a hotspot in recent years. Understanding the interplay between viral reservoirs, clinical outcomes, and public health responses is critical for strengthening preparedness and limiting future transmission.
Methodology:
This study adopted a descriptive, multi-source approach, integrating outbreak reports, clinical investigations, sero-epidemiological surveys, and wildlife reservoir assessments from Kerala between 2018 and 2023. Data were analysed to capture human case characteristics, surveillance outcomes, and bat sampling findings. Laboratory methods included qRT-PCR, ELISA, and genome sequencing, while epidemiological patterns were evaluated using descriptive statistics and comparative analysis across multiple outbreak years.
Results:
Investigations confirmed the persistence of NiV in Pteropus medius bats, with viral RNA and antibodies detected, alongside evidence of distinct viral lineages. Human case data revealed variability in outbreak severity: the 2018 Kozhikode event showed high fatality and nosocomial spread, while subsequent incidents in 2019 and 2021 were rapidly contained with minimal transmission. Public health interventions, including on-site diagnostics, strict contact tracing, and infection control, proved effective in reducing secondary spread. Sero-surveys among contacts indicated no subclinical infections during the 2019 outbreak, highlighting the impact of timely intervention.
Conclusion:
Findings underscore both progress and persisting vulnerabilities in NiV management. Strengthened laboratory capacity, rapid detection, and coordinated responses have contributed to reduced morbidity and mortality in recent outbreaks. However, the continued circulation of NiV within bat populations presents an ongoing risk. Sustained surveillance, proactive wildlife monitoring, and community-level prevention strategies remain essential for mitigating future spillovers and supporting global health security

Nipah Virus, Real-time reverse transcriptase

1. Chadha, M. S., Comer, J. A., Lowe, L., Rota, P. A., Rollin, P. E., Bellini, W. J., Ksiazek, T. G., & Mishra, A. C. (2006). Nipah Virus-associated Encephalitis Outbreak, Siliguri, India. Emerging Infectious Diseases, 12(2), 235. https://doi.org/10.3201/EID1202.051247 [Google Scholar] [Crossref]

2. Chandni, R., Renjith, T. P., Fazal, A., Yoosef, N., Ashhar, C., Thulaseedharan, N. K., Suraj, K. P., Sreejith, M. K., Sajeeth Kumar, K. G., Rajendran, V. R., Remla Beevi, A., Sarita, R. L., Sugunan, A. P., Arunkumar, G., Mourya, D. T., & Murhekar, M. (2020a). Clinical manifestations of nipah virus-infected patients who presented to the emergency department during an outbreak in Kerala State in India, May 2018. Clinical Infectious Diseases, 71(1), 152–157. https://doi.org/10.1093/CID/CIZ789, [Google Scholar] [Crossref]

3. Chandni, R., Renjith, T. P., Fazal, A., Yoosef, N., Ashhar, C., Thulaseedharan, N. K., Suraj, K. P., Sreejith, M. K., Sajeeth Kumar, K. G., Rajendran, V. R., Remla Beevi, A., Sarita, R. L., Sugunan, A. P., Arunkumar, G., Mourya, D. T., & Murhekar, M. (2020b). Clinical manifestations of nipah virus-infected patients who presented to the emergency department during an outbreak in Kerala State in India, May 2018. Clinical Infectious Diseases, 71(1), 152–157. https://doi.org/10.1093/cid/ciz789 [Google Scholar] [Crossref]

4. Hauser, N., Gushiken, A. C., Narayanan, S., Kottilil, S., & Chua, J. V. (2021). Evolution of Nipah Virus Infection: Past, Present, and Future Considerations. Tropical Medicine and Infectious Disease, 6(1), 24. https://doi.org/10.3390/TROPICALMED6010024 [Google Scholar] [Crossref]

5. John, T. J., Rajappan, K., & Arjunan, K. K. (n.d.). Communicable diseases monitored by disease surveillance in Kottayam district, Kerala state, India. [Google Scholar] [Crossref]

6. Luby, S. P., Gurley, E. S., & Hossain, M. J. (2012). TRANSMISSION OF HUMAN INFECTION WITH NIPAH VIRUS. Clinical Infectious Diseases, 49(11), 1743–1748. https://doi.org/10.1086/647951 [Google Scholar] [Crossref]

7. Madhukalya, R., Yadav, U., Parray, H. A., Raj, N., Lupitha, S. S., Kumar, V., Saroj, A., Agarwal, V., Kumar, D., Das, S., & Kumar, R. (2025). Nipah virus: pathogenesis, genome, diagnosis, and treatment. Applied Microbiology and Biotechnology, 109(1), 158. https://doi.org/10.1007/S00253-025-13474-6 [Google Scholar] [Crossref]

8. Ramachandran, R., Jose, M. S., Sahay, R. R., & Shete, A. (2022). Sero-prevalence of Nipah antibodies among close contacts of the index case during 2019 Ernakulam outbreak. Journal of Family Medicine and Primary Care, 11(6), 2479–2482. https://doi.org/10.4103/jfmpc.jfmpc_1731_21 [Google Scholar] [Crossref]

9. Sadanadan, R., Arunkumar, G., Laserson, K. F., Heretik, K. H., Singh, S., Mourya, D. T., Gangakhedkar, R. R., Gupta, N., Sharma, R., Dhuria, M., Jain, S. K., Nichol, S., Gupta, P., & Bhargava, B. (2018a). Towards global health security: Response to the May 2018 Nipah virus outbreak linked to Pteropus bats in Kerala, India. In BMJ Global Health (Vol. 3, Issue 6). BMJ Publishing Group. https://doi.org/10.1136/bmjgh-2018-001086 [Google Scholar] [Crossref]

10. Sadanadan, R., Arunkumar, G., Laserson, K. F., Heretik, K. H., Singh, S., Mourya, D. T., Gangakhedkar, R. R., Gupta, N., Sharma, R., Dhuria, M., Jain, S. K., Nichol, S., Gupta, P., & Bhargava, B. (2018b). Towards global health security: Response to the May 2018 Nipah virus outbreak linked to Pteropus bats in Kerala, India. BMJ Global Health, 3(6). https://doi.org/10.1136/BMJGH-2018-001086, [Google Scholar] [Crossref]

11. Sadanadan, R., Arunkumar, G., Laserson, K. F., Heretik, K. H., Singh, S., Mourya, D. T., Gangakhedkar, R. R., Gupta, N., Sharma, R., Dhuria, M., Jain, S. K., Nichol, S., Gupta, P., & Bhargava, B. (2018c). Towards global health security: Response to the May 2018 Nipah virus outbreak linked to Pteropus bats in Kerala, India. BMJ Global Health, 3(6). https://doi.org/10.1136/BMJGH-2018-001086, [Google Scholar] [Crossref]

12. Sahay, R. R., Yadav, P. D., Gupta, N., Shete, A. M., Radhakrishnan, C., Mohan, G., Menon, N., Bhatnagar, T., Tk, S., Kadam, A. V., Pt, U., Anu Kumar, B., Ap, S., Vk, S., Khobragade, R., Gangakhedkar, R. R., & Mourya, D. T. (2020). Experiential learnings from the Nipah virus outbreaks in Kerala towards containment of infectious public health emergencies in India. Epidemiology and Infection, 148, e90. https://doi.org/10.1017/S0950268820000825 [Google Scholar] [Crossref]

13. Sanker, V., Vellekkat, F., & Dave, T. (2024a). Nipah Virus Outbreaks in Kerala: An Impending Doom? Health Science Reports, 7(11), e70195. https://doi.org/10.1002/HSR2.70195 [Google Scholar] [Crossref]

14. Sanker, V., Vellekkat, F., & Dave, T. (2024b). Nipah Virus Outbreaks in Kerala: An Impending Doom? Health Science Reports, 7(11), e70195. https://doi.org/10.1002/HSR2.70195 [Google Scholar] [Crossref]

15. Sudeep, A. B., Yadav, P. D., Gokhale, M. D., Balasubramanian, R., Gupta, N., Shete, A., Jain, R., Patil, S., Sahay, R. R., Nyayanit, D. A., Gopale, S., Pardeshi, P. G., Majumdar, T. D., Patil, D. R., Sugunan, A. P., & Mourya, D. T. (2021). Detection of Nipah virus in Pteropus medius in 2019 outbreak from Ernakulam district, Kerala, India. BMC Infectious Diseases, 21(1). https://doi.org/10.1186/s12879-021-05865-7 [Google Scholar] [Crossref]

16. T Jacob John, K Rajappan, & K K Arjunan. (2002, July). Communicable diseases monitored by disease surveillance in Kottayam district, Kerala state, India | Request PDF. https://www.researchgate.net/publication/8365217_Communicable_diseases_monitored_by_disease_surveillance_in_Kottayam_district_Kerala_state_India [Google Scholar] [Crossref]

17. Thomas, B., Chandran, P., Lilabi, M. P., George, B., Sivakumar, C. P., Jayadev, V. K., Bindu, V., Rajasi, R. S., Vijayan, B., Mohandas, A., & Hafeez, N. (2019). Nipah virus infection in Kozhikode, Kerala, South India, in 2018: Epidemiology of an outbreak of an emerging disease. Indian Journal of Community Medicine, 44(4), 383–387. https://doi.org/10.4103/ijcm.IJCM_198_19 [Google Scholar] [Crossref]

18. Verma, A., Jain, H., Sulaiman, S. A., Pokhrel, P., Goyal, A., & Dave, T. (2024). An impending public health threat: analysis of the recent Nipah virus outbreak and future recommendations – an editorial. Annals of Medicine & Surgery, 86(2), 638–642. https://doi.org/10.1097/ms9.0000000000001627 [Google Scholar] [Crossref]

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