Global climate anomalies and potential infectious disease risks: 2014-2015

Authors: CHRETIEN, JEAN-PAUL - Armed Forces Health Surveillance Center (AFHSC); ANYAMBA, ASSAF - Goddard Space Flight Center; SMALL, JENNIFER - Goddard Space Flight Center; Gibson, Seth; SANCHEZ, JOSE - Armed Forces Health Surveillance Center (AFHSC); HALBACH, ALAINA - Armed Forces Health Surveillance Center (AFHSC); TUCKER, COMPTON - Goddard Space Flight Center; Linthicum, Kenneth - Ken

Submitted to: PLoS Current Outbreaks
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2015
Publication Date: 1/26/2015
Citation: Chretien, J., Anyamba, A., Small, J.L., Britch, S.C., Sanchez, J.L., Halbach, A.C., Tucker, C.J., Linthicum, K. 2015. Global climate anomalies and potential infectious disease risks: 2014-2015. PLoS Current Outbreaks. 7(1):1-16.

Interpretive Summary: The global climate phenomenon known as El Niño/Southern Oscillation (ENSO) can significantly impact human infectious disease risk worldwide through droughts, floods, and other climate extremes. Throughout summer and fall 2014, El Niño Watch, issued by the US National Oceanic and Atmospheric Administration, assessed likely El Niño development during the Northern Hemisphere fall and winter, persisting into spring 2015. We identified geographic regions where infectious disease transmission may increase if the predicted El Niño occurs using El Niño indicators monitored with earth-orbiting satellites. Ocean Temperatures in the equatorial Pacific (the key indicator of El Niño conditions) and western Indian Oceans were significantly elevated during August-October 2014, consistent with a developing weak El Niño event. Indications are that drier than average conditions will occur across Indonesia and coastal southeast Asia, and wetter than average conditions will occur across northern China, the western Indian Ocean, central Asia, north-central and northeast Africa, Mexico/Central America, the southwestern United States, and the northeastern and southwestern tropical Pacific. Persistence of these conditions could increase transmission of cholera, dengue, malaria, Rift Valley fever, and other infectious diseases in regional hotspots as during previous El Niño events. The current development of weak El Niño conditions has significant potential implications for global public health in winter 2014-spring 2015. Enhanced surveillance and other preparedness measures in predicted infectious disease hotspots could mitigate health impacts.

Technical Abstract: Background: The El Niño/Southern Oscillation (ENSO) is a global climate phenomenon that impacts human infectious disease risk worldwide through droughts, floods, and other climate extremes. Throughout summer and fall 2014, El Niño Watch, issued by the US National Oceanic and Atmospheric Administration, assessed likely El Niño development during the Northern Hemisphere fall and winter, persisting into spring 2015. Methods: We identified geographic regions where infectious disease transmission may increase if the predicted El Niño occurs using El Niño indicators (Sea Surface Temperature [SST], Outgoing Longwave Radiation [OLR], and rainfall anomalies) and literature review of El Niño-infectious disease associations. Results: SSTs in the equatorial Pacific and western Indian Oceans were anomalously elevated during August-October 2014, consistent with a developing weak El Niño event. Teleconnections with local climate is evident in global precipitation patterns, with positive OLR anomalies (drier than average conditions) across Indonesia and coastal southeast Asia, and negative anomalies across northern China, the western Indian Ocean, central Asia, north-central and northeast Africa, Mexico/Central America, the southwestern United States, and the northeastern and southwestern tropical Pacific. Persistence of these conditions could increase transmission of cholera, dengue, malaria, Rift Valley fever, and other infectious diseases in regional hotspots as during previous El Niño events. Conclusions: The current development of weak El Niño conditions has significant potential implications for global public health in winter 2014-spring 2015. Enhanced surveillance and other preparedness measures in predicted infectious disease hotspots could mitigate health impacts.