Sri Lanka has recorded more than 56,422 dengue cases from January to July, adding pressure to the country’s healthcare system as the caseload continues to increase.
Niroshan Peters, 54, a resident of Dematagoda, a densely populated suburb in Colombo, has no option but to live and work in an environment frequently polluted due to careless waste disposal. He blames authorities for not having an effective waste management system, which results in people getting exposed to unhygienic environments.
“Last week, workers from the Colombo Municipal Council (CMC) came to fumigate this area but that alone is not enough,” Peters told Mongabay.
“Every time there is a surge in dengue they suddenly remember to carry out fogging and launch dengue prevention drives. But during the rest of the year people continue to dump waste in abandoned lands and contribute to a never-ending problem.” As of July 1, Sri Lanka’s National Dengue Control Unit (NDCU) has recorded a total of 56,422 dengue cases and 35 deaths. In 2025, a total of 51,000 cases were reported, indicating an alarming increase in incidence this year.
Speaking at a recent briefing, Nalinda Jayatissa, Sri Lanka’s minister of health and media, told Colombo-based journalists that the increasing number of dengue patients could overwhelm hospitals, adding “severe pressure to the healthcare system.”
A dominant serotype
In Sri Lanka, there are four dengue serotypes — a distinct variation within a species of bacteria or virus — and different serotypes emerge during different peak seasons, said Preshila Samaraweera, consultant community physician at NDCU. However, since 2017, when Sri Lanka experienced one of its major dengue outbreaks resulting in more than 186,000 suspected cases and more than 400 deaths, DENV-2 and DENV-3 were identified as the dominant serotypes, she said.
“Our studies indicate that the current infection rate due to DENV-2 is much higher,” Samaraweera told Mongabay. She said dengue cases have been reported every day, indicating a spike in disease transmission.
Reasons for this spike vary from environmental factors to people’s behaviours. According to Samaraweera, Sri Lanka has a tropical climate with warmer and humid environments, typically between 26-30° Celsius (78.8 to 86.0° Fahrenheit) and above 60 per cent humidity levels. High humidity levels allow the dengue mosquito to extend its lifespan to several weeks. These favourable environmental conditions help the Aedes mosquito to thrive, causing rapid transmission, she added.
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