Publications + Presentations

Soebiyanto RP, Anyamba A, Hutchinson S, et al. (2019, December) “El Nino-Southern Oscillation Teleconnections and Global Patterns of Disease Outbreaks”. American Geophysical Union (AGU) Fall Meeting, San Francisco. 

Climate variability associated with the El Niño-Southern Oscillation (ENSO) has marked effects on environmental conditions, favoring several infectious diseases outbreaks including plague, Rift Valley fever, hantavirus, chikungunya, dengue, and cholera. Although studies have linked ENSO events with a particular disease transmission, the impacts of ENSO on climate conditions and disease outbreaks at global scale remains elusive. We analyzed patterns of some disease outbreaks during the strong 2015/2016 El Niño event in relation to climate anomalies derived from satellite measurements. Our results indicate that disease outbreaks in El Niño-connected regions (southeast Asia, Tanzania, western US & Brazil) followed shifts in rainfall, temperature and vegetation, where both drought and flooding occurred in excess (14-81% rainfall departures from normal). Our results showed 2.5-28% increase in disease intensity during years with El Niño events than those without. Plague in Colorado and New Mexico, and cholera in Tanzania were significantly associated with above normal rainfall (p<0.05); while dengue in Brazil and southeast Asia were significantly associated with above normal land surface temperature (p<0.05). During this strong 2015/2016 El Niño event and under the umbrella of US interagency collaborative efforts, we issued alerts when elevated conditions for certain climate extremes were projected in regions with possible outbreaks of climate-sensitive diseases. The alerts led to Rift Valley fever vaccination in livestock in Kenya, averting a potentially damaging outbreaks and economic impacts. We continue to monitor reports of several climate-sensitive diseases worldwide from ProMED. After the 2015/2016 El Niño event, we observed a decreasing trend in intensity of several disease outbreaks. This work not only highlights the global impacts of ENSO in triggering or amplifying disease outbreaks but also demonstrates the prolonged impact of such climate perturbations. Given the changing and variable climate, climate observations and forecasts are going to be a critical tool in disease outbreak preparedness, prevention and control.