WASHINGTON, United States (CMC) – The Pan American Health Organization (PAHO) is urging Caribbean countries to strengthen disease surveillance and prepare health services for possible increases in dengue and chikungunya, amid renewed transmission in parts of the Americas and the anticipated intensification of the El Niño phenomenon.

In an epidemiological update issued on Wednesday, PAHO reported 1.69 million suspected dengue cases across the Americas as of mid-September, including 3,413 severe cases and 571 deaths.

Although the cumulative number of reported cases was 58 per cent lower than during the same period in 2025, the agency said the decline had not been consistent across the region.

Increases had been observed in recent weeks in the Andean, Central American and Caribbean subregions, while all four dengue virus serotypes were circulating in the Americas in 2026.

PAHO also raised concerns about chikungunya, reporting increased transmission between late 2025 and 2026, including renewed circulation in countries and territories where the virus had not been detected for several years.

As of mid-September, 213,919 suspected chikungunya cases had been reported across 20 countries in the region. Of these, 78,481 were confirmed, with 88 deaths recorded.

The agency also pointed to transmission in new areas, outbreaks outside historically affected seasons, longer periods of transmission and increased reports of more severe clinical manifestations.

PAHO is calling on countries to strengthen epidemiological, virological and entomological surveillance, expand diagnostic capacity and ensure that cases are detected early and patients receive timely care.

It also recommended stronger integrated measures to control Aedes mosquitoes, which transmit both diseases.

Health services should be prepared to respond to potential increases in cases at all levels of care, PAHO said, with particular attention to strengthening primary healthcare workers’ ability to recognise dengue warning signs early and prevent progression to severe illness.

Hospitals should also be ready to manage patients with warning signs and severe cases, the agency added.

PAHO further urged countries to improve environmental management, remove containers that collect water and encourage communities, families, local authorities and other sectors to participate actively in mosquito prevention and control.

Eliminating mosquito breeding sites remains a key measure in reducing mosquito populations, the agency said.