Colombia, located in the north of South America, is divided into 32 departments and has more than 51.5 million residents. According to the Ministry of Health in 2022, Colombia reached 99.6% health insurance coverage in its population. However, being the second most unequal country in Latin America and having a multidimensional poverty rate of 12.9%, the country still has significant challenges regarding quality and access to health services.

The Colombian population has been highly affected by vector-borne diseases. In 2020, two of the highest fatality rates reported in the country were due to Chagas disease and leishmaniasis, as per the 2023 health data in the country. In the same year, the highest incidence rates were dengue fever and severe dengue fever, however, the fatality rate of these cases in 2020 was lower than 2019 - as per the official statistics of the Ministry of Health. The health authorities reported arboviruses as the most frequently occurring vector-borne diseases in the country, including dengue, chikungunya, Zika, malaria, leishmaniasis, and Chagas disease. The transmission of these diseases in Colombia is persistent in urban and rural areas, most of which are endemic-epidemic events.

Tolima, located at the centre of Colombia, is a department strongly affected by vector-borne diseases and has therefore been included in the HARMONIZE project. With 1546 cases reported in 2021, dengue is Tolima's most frequent vector-borne disease, followed by leishmaniasis (282 cases reported in 2021) and chikungunya (7 cases reported in 2021). The local health institutions have created different strategies to manage the spread of these diseases. For instance, in 1995, due to the increase in dengue cases in the region, the Tolima Public Health Laboratory created the Entomology Department, aiming to control and collect data on vector-borne diseases.

Tolima is known for having mountain ranges and volcanic reliefs and for being a territory crossed by key water sources, such as the Magdalena River. Its particular geography and its socioeconomic reality- the poverty level in the region exceeded 43% of the population in 2021, as per national statistics, making Tolima a particularly vulnerable region to vector-borne diseases and changes in climate. The area has a varied demographic make-up, that includes indigenous, afro-colombian, palenquero, raizal and rom communities. Most of the population (69%) is concentrated in the urban municipalities. One of the aims of HARMONIZE in Colombia is to understand the changes in vector-borne diseases along an altitudinal gradient. The work in Tolima will help us to better understand the different pressures, both environmental and climate-related, on the transmission cycles of these diseases. The selected hotspots are located on the Eastern side of the Central Andean region in the department of Tolima. There, the HARMONIZE team identified three places with differentiated land use, and that in turn, have different responses to a changing climate.

The main objective of the project in Colombian is to collect environmental information through drone images, and climate information using satellite images and weather stations installed in the three sampling sites, in order to understand the transmission dynamics of vector-borne diseases in the context of a changing climate along an altitudinal gradient. This detailed understanding will allow us to develop computing tools to help stakeholders' decision-making. Two annual field campaigns will be carried out to achieve this objective, where drone flights will occur, and the weather stations will be monitored. Field data will then be processed and used to construct the computing tools needed.

In addition, our team will develop qualitative research to connect the computing tools with the local needs of the communities involved in the project. This will include the perceptions and experiences of decision-makers and data users that work for health and climate institutions, as well as the perspective of the hotspot dwellers. In particular, the HARMONIZE team will work in Tolima on the:

• Installation and monitoring of three weather stations
• Collection of environmental images using drones
• Workshops development with the community on new technological tools for public health monitoring
• Automation of data processing
• Development of predictive mathematical models
• Development of computational tools
• Development of an interactive e-book on perceived links between climate and health in each community involved in the project
• Promote a media campaign, co-created with local consultative community members to raise public awareness about HARMONIZE.