Aedes mosquitoes spreading fast in villages

The prevalence of Aedes mosquitoes has seen a sharp rise in rural areas nationwide this year, coinciding with a notable increase in dengue cases in villages over the past few months, according to a survey by the Directorate General of Health Services (DGHS).

The dominant strain responsible for the transmission of dengue in village areas is Aedes albopictus, the survey found.

The Aedes mosquito is the vector responsible for the transmission of dengue. The species comprises two main types – Aedes aegypti and Aedes albopictus.

Aedes aegypti is predominantly found in urban areas, whereas Aedes albopictus is more active in rural settings. These mosquitoes lay their eggs in various locations, including tree trunks, banana plant barks, and small accumulations of water on leaves, they said.

According to entomologists, managing Aedes albopictus presents greater challenges compared to Aedes aegypti. This complexity makes dengue control efforts in rural areas more difficult. Aedes albopictus thrives in natural reservoirs.

DGHS survey

On 11 July, the DGHS conducted a survey encompassing 10 households in Baldia union of Nesharabad, Pirojpur. The results revealed Aedes larvae presence in seven of these houses. Among the 16 containers inspected within these households, eight were discovered to contain larvae.

Subsequently, on 23 July, Aedes mosquito larvae were detected in seven out of the 10 houses in a village of Angaria union of Dumki, Patuakhali. Among the 37 containers inspected in these houses, Aedes larvae were identified in 10.

Furthermore, Aedes larvae were discovered in 11 of 20 households in Jashore municipality area. The survey revealed that the average Breteau Index (BI) in the municipality was 80.

The Breteau Index indicates the number of positive larvae containers per 100 houses inspected. Under normal conditions, the index of an area should be below 20.

A survey conducted on 75 households across five wards within the Rajshahi city area between 5 and 9 July  found Aedes larvae present in 37.3% houses. The average Breteau Index for Rajshahi city was calculated to be 46.67.

Within the Rajshahi City Corporation area, the composition of Aedes mosquitoes was determined to be 20% Aedes aegypti and 80% Aedes albopictus.

From 23 July to 28 July, the DGHS carried out an extensive survey across 41 out of the 47 wards within Gazipur City Corporation. The results revealed that the Breteau Index exceeded 20 in 24 out of these 41 wards.

The distribution of Aedes mosquitoes in Gazipur indicated a prevalence of 23.6% Aedes aegypti and 76.4% Aedes albopictus.

Between 30 July and 3 August, a survey was conducted in 705 households spanning 27 wards within the Narayanganj City Corporation. Among these houses, Aedes larvae were discovered in 95 of them.

Khalilur Rahman, former chief entomologist of the Directorate General of Health Services (DGHS), told The Business Standard, "Greater emphasis must be placed on dengue control within rural areas compared to urban regions. It is essential to extend spraying campaigns to villages as well. Community awareness regarding maintaining a clean environment is also crucial."

The entomologist added that the dengue situation will see improvement following the onset of winter this year.

Abdul Awal, executive director of the Noakhali Rural Development Society (NRDS), emphasised the necessity for a comprehensive national initiative aimed at dengue control. 

"Drawing parallels to the government's past endeavours in eradicating malaria, a similar nationwide programme is an imperative for addressing the dengue challenge. Engaging the community through a national campaign is vital in this effort," he said.

Moreover, he suggested that a proactive approach involving extensive vaccination should be considered to curb the proliferation of dengue.

Citing examples from other countries like Indonesia that have initiated dengue vaccine administration, he stressed the urgency of introducing a dengue vaccine in our context as well.

17 dengue patients die in 24 hours

Seventeen more dengue patients died and 2,308 were hospitalised across the country in the 24 hours till Thursday morning.

According to the latest figure, 593 dengue patients died in the country and 123,808 were admitted to hospitals this year, according to  DGHS data.

Of the new cases, 875 were reported in Dhaka city and 1,433 were from various parts of the country.

A total of 8,378 dengue patients, including 3,817 in Dhaka, are now receiving treatment at hospitals across the country, according to the DGHS data.