EGU21-14259, updated on 29 Dec 2022
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

The 2018–2019 weak El Niño: Predicting the risk of a dengue outbreak in Machala, Ecuador

Desislava Petrova1, Xavier Rodó1, Rachel Sippy2, Joan Ballester1, Raul Mejía3, Efraín Beltrán-Ayala4, Mercy Borbor-Cordova5, G. Mauricio Vallejo6, Alberto A. Olmedo6, Anna Stewart-Ibarra2, and Rachel Lowe7,1
Desislava Petrova et al.
  • 1Barcelona Institute for Global Health (ISGLOBAL), Climate and Health Programme, Barcelona, Spain (
  • 2Institute for Global Health and Translational Science, SUNY Upstate Medical University, Syracuse, New York
  • 3Instituto Nacional de Meteorología e Hidrología, Guayaquil, Ecuador
  • 4Facultad de Medicina, Universidad Tecnica de Machala, Machala, Ecuador
  • 5Facultad de Ingeniería Maritima y Ciencias del Mar, Escuela Superior Politecnica del Litoral (ESPOL), Guayaquil, Ecuador
  • 6Department of Epidemiological Surveillance, Ministry of Health of Ecuador, Quito, Ecuador
  • 7Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK

Sea surface temperature conditions in the central-eastern tropical Pacific indicated a mild El Niño event in October 2018, which continued throughout the spring of 2019. The global El Niño Southern Oscillation (ENSO) forecast consensus was that these generally weak warm patterns would persist at least until the end of the summer. El Niño and its impact on local climatic conditions in southern coastal Ecuador influence the inter-annual transmission of dengue fever in the region. In this study, we use an ENSO model to issue forecasts of El Niño for the year 2019, which are then used to predict local climate variables, precipitation and minimum temperature, in the city of Machala, Ecuador. All these forecasts are incorporated in a dengue transmission model, specifically developed and tested for this area, to produce out-of-sample predictions of dengue risk. Predictions are issued at the beginning of January 2019 for the whole year, thus providing the longest forecast lead time of 12 months. Preliminary results indicated that the mild El Niño event did not provide the optimum climate conditions for dengue transmission, with the model predicting a very low probability of a dengue outbreak during the typical peak season in Machala in 2019. This is contrary to 2016, when a large El Niño event resulted in excess rainfall and warmer temperatures in the region, and a dengue outbreak occurred 3 months earlier than expected. This event was successfully predicted using a similar prediction framework to the one applied here. With the present study, we continue our  efforts to build and test a climate service tool to issue early warnings of dengue outbreaks in the region.

How to cite: Petrova, D., Rodó, X., Sippy, R., Ballester, J., Mejía, R., Beltrán-Ayala, E., Borbor-Cordova, M., Vallejo, G. M., A. Olmedo, A., Stewart-Ibarra, A., and Lowe, R.: The 2018–2019 weak El Niño: Predicting the risk of a dengue outbreak in Machala, Ecuador, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14259,, 2021.


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