Decrease in Aedes Aegypti Mosquito Population in St. Thomas

The St. Thomas Health Department is reporting a reduction in the population of the Aedes aegypti mosquito, the primary vector for the dengue virus.

This positive development follows coordinated interventions after the passage of Hurricane Melissa on October 28, 2025.

Chief Public Health Inspector for the parish, Pauline Ellington, made the disclosure at the first meeting of the St. Thomas Municipal Corporation for the year, held on January 8 in Morant Bay.

“With respect to environmental health for the period under review, our Breteau Index this month that tells us about the abundance of the aedes aegypti mosquito was 22.3 per cent, down from 25 per cent last month,” she reported.

She noted that the parish is within its target for mosquito control.

“The service level agreement for that particular indicator is 25, between the Ministry of Health and Wellness and the Regional Health Authorities (RHAs), so we are within target for the Breteau Index for the Aedes aegypti mosquito,” she pointed out.

Turning to the Aedes Index, which is a separate but related measure of mosquito breeding sites, Ms. Ellington noted that while the current index of 11.4 per cent is above the desired threshold, it represents the lowest level recorded over the past four years.

She said that the RHA will continue its “enhanced programme to interrupt transmission, as much as possible, of dengue fever.”

In the meantime, Ms. Ellington praised the consistently high quality of the parish’s municipal water supply.

She highlighted that St. Thomas has maintained the international standard of at least 0.5 parts per million (ppm) for free chlorine residual, which is the internationally recommended optimal concentration for disinfecting drinking water in distribution systems.

“St. Thomas has consistently done well in that regard, and I think the parish council is to be commended for that, in particular,” she stated.