Global disease outbreaks associated with the 2015-2016 El Niño event

Authors: ANYAMBA, ASSAF - Universities Space Research Associaton; CHRETIEN, JEAN-PAUL - Department Of Defense; Gibson, Seth; SOEBIYANTO, RADINA - Universities Space Research Associaton; SMALL, JENNIFER - Goddard Space Flight Center; JEPSEN, RIKKE - Goddard Space Flight Center; FORSHEY, BRETT - Department Of Defense; SANCHEZ, JOSE - Department Of Defense; SMITH, RYAN - United States Air Force; HARRIS, RYAN - United States Air Force; TUCKER, COMPTON - Goddard Space Flight Center; KARESH, WILLIAM - Ecohealth Alliance; Linthicum, Kenneth - Ken

Submitted to: Nature Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2018
Publication Date: 2/13/2019
Citation: Anyamba, A., Chretien, J., Britch, S.C., Soebiyanto, R.P., Small, J.L., Jepsen, R., Forshey, B.M., Sanchez, J.L., Smith, R.D., Harris, R., Tucker, C.J., Karesh, W.B., Linthicum, K. 2019. Global disease outbreaks associated with the 2015-2016 El Niño event. Nature Scientific Reports. https://doi.org/10.1038/s41598-018-38034-z.
DOI: https://doi.org/10.1038/s41598-018-38034-z

Interpretive Summary: Fluctuations in weather and climate regulates how ecosystems function which in turn affects abundance of plant and animal life, in particular populations of disease vector insects such as mosquitoes which influence the potential for occurrence of disease outbreaks. From year to year the El Niño-Southern Oscillation (ENSO) phenomenon has profound impacts on global climate and weather, often defining major peaks in drought and flood conditions. These extremes in precipitation and temperature resulting from ENSO events are now known to be the drivers of a range of insect vector- and water-borne diseases whose peaks in activity coincide, lag, or follow precipitation and temperature departures from normal. The persistence of extreme conditions of either temperature or precipitation impacts the ecology and habitat size of different insect vectors; vector population growth rates and dynamics, distribution, and seasonality. In this paper we describe how the 2015-2016 El Niño event created environmental conditions that caused worldwide regional clusters of disease outbreaks, including such diseases as chikungunya, hantavirus, Rift Valley fever, cholera, plague and Zika.

Technical Abstract: Interannual climate variability patterns associated with the El Niño-Southern Oscillation phenomenon result in climate and environmental anomaly conditions worldwide that directly favor outbreaks of variety of diseases of public health concern including chikungunya, hantavirus, Rift Valley fever, cholera, plague, and Zika. We analyzed locations of these key disease outbreaks during the strong 2015-2016 El Niño event in relation to weather and ecological anomalies derived from satellite measurements. Disease outbreaks in multiple El Niño-connected regions worldwide (including Southeast Asia, Tanzania, western US, and Brazil) followed shifts in rainfall, temperature, and vegetation in which both drought and flooding occurred in excess (34% - 58% precipitation departures from normal). These shifts favored ecological conditions appropriate for pathogens and their vectors to emerge and propagate clusters of diseases. Our analysis indicates that intensity of disease activity was approximately 10% – 33% higher during years with El Niño events than those without. Routine and ongoing global satellite monitoring of key climate variable anomalies calibrated to specific regions could identify regions at risk for emergence and propagation of disease vectors. Such information can provide sufficient lead-time for outbreak prevention and potentially reduce the burden and spread of ecologically coupled diseases.