El Niño Southern Oscillation as an early warning tool for dengue outbreak in India

Abstract

Background Dengue is rapidly expanding climate-sensitive mosquito-borne disease worldwide. Outbreaks of dengue occur in various parts of India as well but there is no tool to provide early warning. The current study was, therefore, undertaken to find out the link between El Niño, precipitation, and dengue cases, which could help in early preparedness for control of dengue. Methods Data on Oceanic Niño Index (ONI) was extracted from CPC-IRI (USA) while the data on monthly rainfall was procured from India Meteorological Department. Data on annual dengue cases was taken from the website of National Vector Borne Disease Control Programme (NVBDCP). Correlation analysis was used to analyse the relationship between seasonal positive ONI, rainfall index and dengue case index based on past 20 years’ state-level data. The dengue case index representing ‘relative deviation from mean’ was correlated to the 3 months average ONI. The computed r values of dengue case index and positive ONI were further interpreted using generated spatial correlation map. The short-term prediction of dengue probability map has been prepared based on phase-wise (El Niño, La Niña, and Neutral) 20 years averaged ONI. Results A high correlation between positive ONI and dengue incidence was found, particularly in the states of Arunachal Pradesh, Chhattisgarh, Haryana, Uttarakhand, Andaman and Nicobar Islands, Delhi, Daman and Diu. The states like Assam, Himachal Pradesh, Meghalaya, Manipur, Mizoram, Jammu & Kashmir, Uttar Pradesh, Orissa, and Andhra Pradesh shown negative correlation between summer El Niño and dengue incidence. Two - three month lag was found between monthly ‘rainfall index’ and dengue cases at local-scale analysis. Conclusion The generated map signifies the spatial correlation between positive ONI and dengue case index, indicating positive correlation in the central part, while negative correlation in some coastal, northern, and north-eastern part of India. The findings offer a tool for early preparedness for undertaking intervention measures against dengue by the national programme at state level. For further improvement of results, study at micro-scale district level for finding month-wise association with Indian Ocean Dipole and local weather variables is desired for better explanation of dengue outbreaks in the states with ‘no association’.

Spatial and temporal trends of dengue infections in Curaçao: A 21-year analysis

“…These findings diverge from previous research that mainly focused on the positive correlation between dengue outbreaks and El Niño, the warming phase of ENSO ( Vincenti-Gonzalez et al, 2018 ; Xiao et al, 2017 ; Pramanik et al, 2020 ). The contrast in our results underscores the complexity of the relationship between ENSO and dengue infections, indicating that different ENSO phases may have varying effects on dengue transmission dynamics.…”

“…On the other hand, studies in Curaçao ( Limper et al, 2010 ; Limper et al, 2016 ) and Guadeloupe ( Gharbi et al, 2011 ) identified a decrease in mean temperature to be related to more dengue cases. Relevant to this aspect is the occurrence of El Niño Southern Oscillation (ENSO), as there are multiple studies ( Vincenti-Gonzalez et al, 2018 ; Xiao et al, 2017 ; Pramanik et al, 2020 ) that revealed a link between dengue and the warming phase of ENSO.…”

A Review of Dengue’s Historical and Future Health Risk from a Changing Climate

“…Extreme prolonged climatic events can also drive the potential for dengue transmission by influencing human behavior, such as droughts that may result in people increasing water storage practices that could serve as breeding grounds for mosquitos [ 77 ]. Broader climate phenomena such as sea surface temperature or Oceanic Niño Index, can influence weather patterns (i.e., changing temperature or precipitation), and depending on the geography can further contribute towards localized impacts as mentioned, thereby altering transmission dynamics [ 78 , 79 ].…”

Climate Anomalies and Spillover of Bat-Borne Viral Diseases in the Asia–Pacific Region and the Arabian Peninsula

“…ENSO-related climate variability is also a known driver of the emergence and outbreaks of infectious diseases [ 3 , 10 ]. Outbreaks of numerous infectious diseases, such as cholera [ 11 ], Rift Valley fever [ 12 ], visceral leishmaniasis [ 13 ], dengue [ 14 , 15 ], Zika virus [ 16 ], and malaria [ 17 ], among others, have been linked to the ENSO. The emergences of some viral diseases of bat origin, such as the Hendra virus (HeV) in Australia and the Nipah virus (NiV) in Malaysia, have also been associated with El Niño events [ 18 , 19 ].…”