For Kasun Chameera, who lives in Sri Lanka’s densely populated capital Colombo, dengue fever is a disease which has afflicted many loved ones, including his brother.

“We fear death when we hear about dengue,” Chameera said. “It's present almost everywhere in my district, and spreads faster in the city than in the villages.”

His brother “suffered a lot from it,” Chameera said. “For at least one to two months, he would be tired walking just 10 steps. We were very scared.”