Yangon is a tropical metropolis susceptible to infectious disease outbreaks. The Lepto Yangon Platform was developed to integrate climate and environmental risk information from satellites into health surveillance systems to develop early warnings and guide disease control. The platform was developed to provide early warnings of the suitable environments for leptospirosis transmission, in order to improve its surveillance. Leptospirosis is a common bacterial zoonosis that remains rarely diagnosed in Southeast Asia despite a high morbidity, as shown in several active investigations. Outbreaks of leptospirosis are strongly associated to water and often follow heavy rainfall and flooding events. The integrated data platform was developed by the French National Research Institute for Sustainable Development (IRD) and partners of the ClimHealth project, funded by the French National Centre for Space Studies (CNES) and accredited by the Space Climate Observatory (SCO) international initiative. It builds on the ECOMORE 2 project,137 coordinated by the Institut Pasteur, and funded by the Agence Française de Développement (AFD). In Yangon, this project supported the National Health Laboratory and hospitals of the Yangon metropolitan area to develop the diagnosis of leptospirosis and increase awareness.

The platform aims to model suitable climate and environmental conditions for leptospirosis through Earth observation, over the agglomeration of Yangon, Myanmar. The ECOMORE 2 project retrospectively analysed the locations of leptospirosis confirmed cases (versus non-leptospirosis controls) in 2019 and 2020. Time series of vegetation, water and moisture indices from Sentinel-2 satellite imagery (available at 10-meters spatial resolution, every 4 days, from the European Space Agency’s Copernicus Programme) were produced to describe the dynamics of the environment around the locations of residence. This process relied on the use of the Sen2Chain processing chain developed in previous projects. The most relevant indices were used to build a spatiotemporal prediction model of positive versus negative locations. This model was spatialized on homogeneous landscape units from the point of view of land use and describing the whole study area. The acquisition of Sentinel-2 images, their processing and the modelling were then automated as soon as a new image becomes available (every 5 days). An online information system was created to display this dynamic mapping of suitable environments for leptospirosis transmission and to inform the epidemiologists and physicians of the study. The online platform has been developed with the open-source software R and R-Shiny, and the processing chains are coded in Python, to be part of an open science approach.

Lepto Yangon is an online early warning system providing information about the suitable environment for leptospirosis transmission in the metropolitan area of Yangon. A new risk map is produced every five days, as soon as a new Sentinel-2 image is available. The tool allows retrospective consultation of any date since the first image was available in March 2016 (over seven years ago). By clicking on the map, the user can select a landscape unit and view the temporal dynamics of the risk for that unit (that is, whether the risk is increasing or decreasing).138 The user can also view the vegetation, water and moisture indicators to get an idea of the environmental data more specifically. The platform is designed to be used by epidemiologists and physicians to visualize the most at-risk areas and those where the risk is increasing, to raise physicians’ awareness of leptospirosis, which is often confused with other fevers.

Implementing this tool in other territories is facing methodological challenges regarding the volume of satellite data to be processed. Detailed knowledge of the ecology of leptospirosis and exposure factors to adapt the models in different contexts is also needed. This already operational risk monitoring tool provides proof of concept for the development of climate and environmental monitoring systems to increase the vigilance of health personnel and populations to the risk of leptospirosis.

Lepto Yangon provides actionable and real-time (5-day) updates of leptospirosis transmission risk to epidemiologists and hospitals in Yangon.