Where dengue mosquitoes breed in Sri Lanka depends on the district, not on a single national checklist of sites, a specialist at the National Dengue Control Unit has said — a point with direct consequences for how control campaigns are targeted.
Dr Prashila Samaraweera, Consultant Specialist at the unit, told the Daily Mirror that prominent breeding grounds differ from one area to another according to local conditions and water management practices, in an interview published on Saturday.
The regional pattern
Two examples given are specific enough to act on:
- In Batticaloa and Kalmunai, shallow wells can serve as breeding sites.
- In Gampaha and Kalutara districts, pineapple plantations and the coconut shells used to collect latex in rubber plantations provide suitable conditions.
Dr Samaraweera also said certain water management systems in some areas can create conditions favourable to breeding.
That is a different list from the one householders are usually given. A campaign built around discarded tyres and roof gutters in Colombo would not find the sites that matter in a rubber-growing division.
Around the home
For domestic settings, Dr Samaraweera grouped the risk into discarded items that collect water, broadly divided into degradable waste, non-degradable waste, and items set aside temporarily before disposal — the third category being the easiest to overlook.
“Water can accumulate in and around homes, including in refrigerator trays, while broken and discarded material can collect water and become mosquito breeding sites. Items, such as paint buckets, are kept for possible reuse and can become breeding sites when they collect water.”
She also corrected a common misreading of the advice to look for clean water:
“Mosquitoes carrying the dengue virus breed in clean water. By clean water, we mean clear water and not necessarily potable water.”
Why cross-country comparisons mislead
Dr Samaraweera said Sri Lanka has adopted aspects of Thailand’s dengue management model, and described both countries as having strong systems in the South Asian and Southeast Asian regions.
She cautioned against reading national case totals side by side. In Sri Lanka a case can be classified as suspected dengue when two symptoms are present, while some countries apply different criteria and weight confirmed cases more heavily. Reported numbers therefore reflect the surveillance and classification rules in use as well as actual transmission.
Sri Lanka recorded 10,157 cases in August, after daily counts fell sharply through the middle of the year.
Not reported
The interview does not give current case figures, name the districts reporting the most cases now, or say whether the unit’s inspection guidance has been revised district by district to match the variation described.
