The global toll of dengue fever is becoming well known, with rising temperatures contributing to severe outbreaks that made 2019 the worst year on record for the disease.
In 1970 only nine countries faced severe dengue outbreaks. But the disease, which is spread by mosquitoes that can only survive in warm temperatures, is now seen in more than 100 countries. There are thought to be 390m infections each year
More than a million of those cases were in south-east Asia, hitting the poorest households hard and stretching health services.
The epidemic is exacerbated by poor infrastructure and lack of access to healthcare, with struggling health services overwhelmed by outbreaks.
Photographer Luke Duggleby and journalist Laure Siegel