# Climate change and the rising threat of vector-borne diseases in the Andes

## TL;DR

Climate change is enabling vector-borne diseases to spread to high-altitude regions in the Andes, threatening vulnerable populations.

## Contribution

The paper introduces the climate–vector–inequity triad to explain how climate and social factors jointly increase disease risk in highland areas.

## Key findings

- Vector-borne diseases are now appearing in Andean regions above 2000 m due to climate change.
- Social vulnerabilities like poverty and poor health access worsen outbreak impacts in highland communities.
- Altitude-sensitive surveillance and One Health policies are needed to address this emerging threat.

## Abstract

Vector-borne diseases such as dengue, malaria, leishmaniasis, and Chagas disease continue to cause millions of infections and thousands of deaths each year, particularly in low- and middle-income regions of South America. In recent years, climate change has profoundly altered the distribution and behavior of arthropod vectors, promoting their expansion into new ecological niches, including high-altitude areas of the Andes once considered unsuitable for transmission. Countries such as Colombia, Ecuador, Peru, and Bolivia have reported outbreaks of dengue and malaria in populations residing above 2000 m above sea level, revealing an unprecedented epidemiological shift. Importantly, this emerging scenario reflects more than an environmental process: it also exposes deep social vulnerabilities linked to poverty, deforestation, and limited access to health services, which can magnify outbreak impacts and constrain timely response. Within this context, the climate–vector–inequity triad offers an integrative perspective to understand how climatic and structural factors converge to amplify risk. Addressing this challenge requires altitude-sensitive surveillance systems, ecosystem restoration, and health policies grounded in the One Health approach to strengthen prevention, diagnosis, and response capacity in highland regions of the Andes, particularly in vulnerable indigenous and rural communities across Ecuador, Colombia, Peru, and Bolivia where socioeconomic disparities exacerbate transmission risks.

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•Vectors have expanded to higher-altitude areas due to the influence of climate change.•Andean countries have reported cases of vector-borne diseases in regions where they previously did not exist.•It is necessary to establish entomological surveillance in high-altitude areas.

Vectors have expanded to higher-altitude areas due to the influence of climate change.

Andean countries have reported cases of vector-borne diseases in regions where they previously did not exist.

It is necessary to establish entomological surveillance in high-altitude areas.