Short-term effect of temperature and precipitation on the incidence of West Nile Neuroinvasive Disease in Europe: a multi-country case-crossover analysis

Moirano, Giovenale; Fletcher, Chloe; Semenza, Jan C.; Lowe, Rachel

doi:10.1016/j.lanepe.2024.101149

Published January 1, 2025 | Version v1

Journal article Open

Short-term effect of temperature and precipitation on the incidence of West Nile Neuroinvasive Disease in Europe: a multi-country case-crossover analysis

1. Barcelona Supercomputing Center
2. University of Turin
3. Pompeu Fabra University
4. University of Heidelberg
5. Umeå University
6. Catalonian Institute for Acances Studies and Research
7. London School of Hygiene & Tropical Medicine

Background

In recent years, Europe has experienced several outbreaks of West Nile Virus (WNV), a mosquito-borne pathogen. This study aims to quantify the impact of weekly mean temperature and cumulative precipitation on human cases of West Nile Neuroinvasive Disease (WNND), to assess the feasibility of climate-informed early warning systems for severe forms of WNV infection.

Methods

Using a space-time-stratified case-crossover design, the short-term effects of meteorological factors on WNND cases reported in Europe from 2014 to 2022 were examined. Distributed lag nonlinear models were implemented in conditional logistic regressions to assess the delayed and nonlinear effects of temperature and precipitation on WNND risk as well as to estimate the Attributable Fraction (AF) of cases to extreme values of the two meteorological factors.

Findings

Between 2014 and 2022, Europe reported 3437 WNND cases. Both meteorological factors recorded in the 8 weeks before symptom onset showed positive and delayed effects on WNND risk. The strongest effect was found for weekly mean temperatures at 2 weeks lag (Odds Ratio (OR): 1.15; 95% Confidence Interval (CI) 1.12–1.19) and for weekly cumulative precipitation at 3 weeks lag (OR: 1.12; 95% CI 1.09–1.16). Of all WNND cases analyzed, 36.4% (95% CI, 31.3%–40.3%) could be attributed to weekly mean temperatures exceeding the 25 °C, while 13.1% (95% CI, 9.5%–16.4%) to weekly cumulative precipitations exceeding 40 mm.

Interpretation

These findings emphasize the significance of short-term variations in temperature and precipitation in driving WNND incidence in Europe. Meteorological factors can be used to operationalize early warning systems to reduce the disease burden from WNV infections, which are continually increasing across the continent.

Funding

European Union’s Horizon Europe research and innovation programme.

Technical info

Data sharing statement

Human cases data are available upon request at The European Surveillance System (https://www.ecdc.europa.eu/en/publications-data/european-surveillance-system-tessy). Meteorological data are available at the Copernicus Climate Change Service (https://climate.copernicus.eu/). An example dataset and a sample of the code to reproduce the analysis is available: https://earth.bsc.es/gitlab/ghr/wnv_casecrossover.

Notes

Contributors

Conceptualization: GM, RL; Data curation: GM; Formal analysis: GM; Funding acquisition: RL; Investigation: GM, CF, JS, RL; Methodology: GM, RL; Software: GM, CF, RL; Supervision: JS, RL; Validation: CF, RL; Visualization: GM, CF, JS, RL; Writing—original draft: GM, JS, RL; Writing– review & editing: GM, CF, JS, RL.

Other

Acknowledgements

The authors acknowledge funding from the European Union’s Horizon Europe research and innovation programme under grant agreements No. 101086640 (E4Warning, https://www.e4warning.eu) and No. 101057554 (IDAlert, https://idalertproject.eu). IDAlert is part of the EU climate change and health cluster (https://climate-health.eu). The authors acknowledge the European Surveillance System and ECDC. The views and opinions of the authors expressed herein do not necessarily state or reflect those of ECDC. The accuracy of the authors' statistical analysis and the findings they report are not the responsibility of ECDC. ECDC is not responsible for conclusions or opinions drawn from the data provided. ECDC is not responsible for the correctness of the data and for data management, data merging and data collection after provision of the data. ECDC shall not be held liable for improper or incorrect use of the data.

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