The dengue situation, which was alarming in 2019, is comparatively more severe in the country this year, according to the latest pre-monsoon survey conducted by the Directorate General of Health Services (DGHS).
The density of Aedes mosquitoes, the primary vectors of dengue, and the number of potential hotspots have surged to the highest levels in the past five years.
Out of the 98 wards within the two city corporations of Dhaka, 55 wards are at high risk of dengue, in stark contrast to the 21 high-risk wards identified in 2019.
According to the DGHS and the pre-monsoon survey, Aedes mosquitoes, which carry the dengue virus, are prevalent in all areas of Dhaka's two city corporations.
There are fears that the dengue outbreak could last as long as it did last year. Despite the city corporation's efforts, the situation may worsen if residents do not take precautions.
This year, until Tuesday, the death toll from dengue fever has reached 61, with a total of 9,871 reported cases of infection. The number of deaths and cases detected within a 24-hour period, from Monday 8:00am to Tuesday 8:00am, was the highest recorded this year.
During this time, five individuals lost their lives, and 678 people were admitted to hospitals. This situation is unprecedented during the first six months of any year in the country. In 2019, eight deaths and 2,208 reported cases were recorded during the same period.
The National Malaria Elimination & Aedes Transmitted Diseases Control Programme run by Communicable Disease Control under DGHS conducts mosquito surveys in Dhaka north and south city corporation areas three times a year.
The surveys are conducted before monsoon, during monsoon and after monsoon. This year's pre-monsoon survey was conducted from 17 June to 27 June. The survey was conducted in 3,149 houses of total 98 wards of two cities of Dhaka. The results of this pre-monsoon survey were released yesterday.
All indexes are alarming this year
The index for measuring the density of Aedes mosquito larvae is known as 'Breteau index'. And how many houses have the presence of Aedes mosquitoes, the measurement of it is the house index.
An alarming picture of the dengue situation has emerged in these two indicators of the pre-monsoon survey.
Nazmul Islam, director of the CDC, said that out of 98 wards of the two cities of Dhaka, the Breteau index is more than 20 in 55 wards. This means that more than 20 containers out of 100 of these areas have mosquitoes or larvae. Last year only 3 out of 98 wards had Breteau index above 20.
The surveyors conducted visits to 40 wards of Dhaka North City Corporation (DNCC) and 58 wards of Dhaka South City Corporation (DSCC). During their visits to a total of 3,149 houses in these wards, Aedes mosquito larvae were discovered in 549 houses. Among them, 271 houses in DNCC and 278 houses in DSCC were found to have Aedes mosquito larvae.
The areas with the highest mosquito density in DNCC were identified as Moghbazar, Adabar, Mohammadpur, Manipur, and North Badda. In DSCC, the areas with the highest mosquito density were Nawabpur, Distillery Road, Azimpur, Hazaribagh, Kanthal Bagan, and Science Lab.
The current house index, which represents the percentage of houses where Aedes mosquitoes were found, is a cause for concern. Typically, a house index exceeding 10 in a ward is considered alarming. This time, out of the 98 wards, the house index exceeds 10 in 80 wards, highlighting the severity of the situation. In comparison, only 19 wards had a house index above 10 last year.
During the survey release, Ahmedul Kabir, the additional director general of the DGHS, expressed the gravity of the situation. The survey findings indicate a significant increase in mosquito density compared to the previous year (2019-20). This year, due to delayed monsoons that are anticipated to extend further, the dengue season is expected to be prolonged, surpassing the duration of the previous year.
Population of Aedes mosquito higher in high-rise buildings
Based on the survey data, a higher percentage of Aedes mosquito larvae were discovered in multi-storied buildings- approximately 44 per cent. Single-unit houses and buildings under construction accounted for the next highest number of larvae, comprising around 40 per cent. The larvae were predominantly found in waterlogged areas, plastic drums, pots, and flower pots.
Kabirul Bashar of Zoology Department of Jahangirnagar University said that the process of containing Aedes mosquito is complex. Access to multi-storied building is difficult. It will be difficult to handle the dengue situation if the city dwellers are not involved. Dengue hotspots (areas of high transmission) should be given special attention. Special measures should be taken to repel mosquitoes in hotspots.
Director general of the DGHS Abul Bashar Mohammed Khurshid Alam presided over the release of the survey. Additional director general of DGHS Rasheda Sultana, director of Institute of Epidemiology, Disease Control and Research (IEDCR) professor Tahmina Shirin and directors of various hospitals in Dhaka were present on the occasion.
Dissatisfaction over mosquito repelling drives
Despite the prior warning issued by the health directorate regarding the dengue situation a few months ago, journalists have highlighted the objections raised by the two cities of Dhaka regarding the authorities' alleged lack of proper initiatives in response to the issue.
Lieutenant Colonel Golam Mostafa Sarwar, deputy chief health officer of Dhaka north, said, "I am not satisfied with my work in containing mosquitoes. The city corporation is making maximum efforts to increase public awareness. The city corporation will conduct a special operation from 8 July to 13 July. On the other hand, Dhaka south chief health officer (Acting) Fazle Shamsul Kabir said that they are continuing mosquito control drives.
In contrast, Ahmedul Kabir, the additional director general of DGHS, stated that the efforts of the city corporation to combat dengue should be amplified.
Apprehension of worsening the situation
Delay in hospitalisation of dengue patients significantly increases the risk of death. A review conducted by the Communicable Disease Control (CDC) under the Directorate General of Health Services (DGHS) analysed data from 50 dengue-related deaths this year.
The study revealed that approximately 80 per cent of the patients died within one to three days of being admitted to hospital.
According to Mushtaq Hussain, a public health expert, the number of dengue cases and fatalities in the first six months of this year has exceeded any previous records. Typically, the dengue outbreak in the country tends to intensify after June. Consequently, there is a likelihood of a rise in the number of infection in the upcoming days. With a high number of infections, there is a significant risk of increased fatalities as well.
He emphasises that immediate action is crucial to prevent the situation from deteriorating further in the days ahead.