An early warning system for diarrheal diseases with seasonal to sub-seasonal (S2S) lead time is urgently needed to prevent disease outbreaks in communities impacted by extreme weather events that are increasing in frequency, duration, and intensity. While the overall burden of diarrheal diseases has been declining, in large part due to oral rehydration therapy (ORT), countries in the Asia Pacific Region still experience elevated rates of diarrheal disease morbidity and mortality, with more than 873,000 deaths/year reported in South Asia alone. 

Despite considerable interest, success has been limited primarily because of the shortcomings of weather-based and climate projection-based warning systems. Weather-based warnings (7 to 10 days lead time) do not provide enough time for public health professionals and communities to plan for the threats, while climate projection-based warnings (50 to 100 year time horizon) are too distant in the future to guide meaningful public health preparedness discussions at present. Through collective engagement over the past decade, our team has learned that public health practitioners are seeking early warning systems with seasonal to sub-seasonal lead times as they can provide adequate time to prepare for and respond to projected climate change-related threats that are looming on the horizon. 

To address this need, our interdisciplinary team of Swiss and U.S. scientists will partner with scientists, NGOs, governmental, and community organizations from the Asia Pacific Region, including Taiwan, India, China, Vietnam, Nepal, Bangladesh, and Indonesia (hereafter referred to as our focus area) to establish a multinational consortium that will perform comparative analyses of diarrheal disease risk associated with extreme weather events. Our consortium will develop a transferable solution — S2S early warnings for diarrheal disease — that will be implemented across the focus area to reduce extreme weather-related diarrheal disease burdens and improve community resilience to climate change. We will achieve these overall objectives through the: creation of uniform exposure metrics (extreme heat and extreme precipitation events) for the focus area (Work Package (WP) 1); development of an empirical relationship between phases of the El Niño-Southern Oscillation (ENSO) and frequency of extreme heat and extreme precipitation events, and further characterization of how this relationship varies by geographic location and season (WP2); establishment of a historical database of diarrheal diseases in the focus area (WP3); characterization of the relationship between extreme heat and precipitation events and risk of diarrheal disease, and how this relationship differs across geographic and socio-demographic factors (WP4); and development of an S2S diarrheal disease early warning system and risk maps at sub-national levels (WP5). Our focus areas include countries within the Asia-Pacific Region because this region accounts for the highest-burden of diarrheal disease morbidity globally and includes countries that are considered to be among the most vulnerable to the threats of climate change. 

Resources

1. CNN. More than 100 dead and 6 million affected by flooding across South Asia. 7-16-2019. https://www.cnn.com/2019/07/16/india/nepal-india-bangladesh-floods-intl-hnk/index.html 
2. BBC. Monsoon floods displace millions in India. 7-16-2019. https://www.bbc.com/news/world-asia-48979668
3. Climate Change 2014- Mitigation of Climate Change. Working Group III Contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, Uk, and New York, USA: Cambridge University Press; 2014.
4. Managing the risks of extreme events and disasters to advance climate change adaptation: Special report to the Intergovernmental Panel on Climate Change. Cambirdge, UK; New York, USA: Cambridge Uniersity Press; 2012.
5. Luber G, Knowlton K, Balbus J, Frumkin H, Hayden M, Hess J et al. Climate Change Impacts in the United States. In: Melillo JM, Richmond T, Yohe G, editors. The Third National Climate Assessment. Washington DC: US Global Change Research Program; 2014. p. 220-56.
6. GBD 2016 Diarrhoeal Disease Collaborators. Estimates of the global, regional, and national morbidity, mortality, and aetiologies of diarrhoea in 195 countries: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Infect Dis 2018 November;18(11):1211-28.
7. Eckstein, D., Hutfils, ML, and Winges, M. Global Climate Risk Index 2019. Bonn. Germany: GERMANWATCH; 2019.
8. Cai W, Borlace S, Lengaigne M, van Rensch P, Collins M, Vecchi G, Timmermann A, Santoso A, McPhaden MJ, Wu L, England MH, Wang G, Guilyardi E, Jin FF. Increasing frequency of extreme El Nino events due to greenhouse warming. Nature Clim Change 2014 February;4(2):111-6.