This project was funded by the Pacific Community (SPC) and was developed through a close collaboration between SPC and the Research Institute for Sustainable Development (IRD).

Model leptospirosis

The prediction model for leptospirosis in tropical island was derivated from Douchet et al. (2024) (1).

Variables definitions

Model exploration and fitting

We used svm models to estimate leptospirosis dynamics in tropical islands.

Alert threshold definition

The alert threshold was defined relative to the season. The default values 25%, 75% and 90% cut the dynamic in 4 groups being :

• Lower than usual: number of cases and incidence that belongs to the 25% lowest observed values for the given month

• As usual: number of cases and incidence that are part of the endemic channel, i.e. that are similar to the season (defined as the median).

• Higher than usual: number of cases and incidence that belong to the 25% highest values observed for the given month but are not within the 10 % highest values

• Extreme values: number of cases and incidence that belong to the 10% highest values observed for the given month

References

(1) Douchet, L., Menkes, C., Herbreteau, V., Larrieu, J., Bador, M., Goarant, C., & Mangeas, M. (2024). Climate-driven models of leptospirosis dynamics in tropical islands from three oceanic basins. PLOS Neglected Tropical Diseases, 18(4), e0011717.

Health data

The data presented on this website consists of laboratory-confirmed cases of leptospirosis reported through national and regional disease surveillance systems in Fiji (1), New Caledonia, Futuna and French Polynesia. The leptospirosis case data has been aggregated on a monthly basis and organized by administrative divisions, such as islands, districts, and communes.

Acknowledgments

We thank the various stakeholders that provided leptospirosis data:

• The Institut Pasteur and the Department of Health and Social affairs kindly provided leptospirosis data for New Caledonia,

• For French Polynesia, spatio-temporal surveillance data were kindly provided by the Government of French Polynesia and by the Direction of Health of French Polynesia,

• Dr Mike Kama from the Fiji Ministry of Health kindly provided Fiji surveillance data,

• Clément Couteaux from Agence de Santé de Wallis & Futuna kindly provided data for Futuna.

Population data

Climate data

ERA5 climate data are downloaded from Copernicus database (2). These gridded climate reanalysis are downloaded at a resolution of 25km and resampled at a resolution of 100km to match the resolution of the seasonal forecasts. The displayed daily climate data (temperature and precipitation) are averaged over the island.

Boundaries of the pacific islands

References

(1) Rees, E. M., Lotto Batista, M., Kama, M., Kucharski, A. J., Lau, C. L., & Lowe, R. (2023). Quantifying the relationship between climatic indicators and leptospirosis incidence in Fiji: A modelling study. PLOS Global Public Health, 3(10), e0002400.

(2) Hersbach, H., Bell, B., Berrisford, P., Biavati, G., Horányi, A., Muñoz Sabater, J., Nicolas, J., Peubey, C., Radu, R., Rozum, I., Schepers, D., Simmons, A., Soci, C., Dee, D., Thépaut, J-N. (2023): ERA5 hourly data on single levels from 1940 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS), DOI: 10.24381/cds.adbb2d47 (Accessed on 10-06-2024)