On September 29, Bangladesh witnessed the number of dengue cases surpass 200,000.
Subsequently, in the next 51 days, dengue-related hospitalizations soared to over 300,000, highlighting a substantial increase of over 100,000 cases within a relatively short time frame.
The unprecedented number shattered the previous record set in 2019 when 101,554 cases were recorded.
Till Tuesday morning, the DGHS recorded 303,536 dengue cases and 297,512 recoveries this year.
Although dengue is endemic in Bangladesh with recurrent outbreaks, experts point out that the recent surge highlights the alarming shift in its prevalence, transforming it into a year-round threat.
Consequently, there is a pressing need to formulate an action plan extending to 2030, as relying solely on the dengue vaccine appears impractical given the current circumstances.
The cumulative data reveal that since 2000, the number of dengue patients admitted to hospitals has witnessed a staggering increase.
Before 2018, the number of dengue hospitalization never exceeded 10,000. However, the situation has intensified since 2021, with patients consistently admitted each month.
Cases outside Dhaka doubled
This year, the number of patients outside Dhaka has doubled compared to those within the capital, indicating a concerning spread of the disease beyond urban areas.
Contrary to its earlier classification as a “city disease”, dengue has permeated rural areas, with all districts reporting cases in 2023.
This year, almost twice as many patients were found outside Dhaka as compared to Dhaka.
Experts attribute this expansion to the prevalence of Aedes albopictus, a mosquito species with distinct breeding habits, posing a challenge to traditional prevention measures.
Infection time changed
A retrospective analysis of infection patterns reveals a shift in the timing of dengue outbreaks. Once confined to specific months, cases are now reported consistently throughout the year, indicating a substantial change in the temporal dynamics of the disease.
Entomologists attribute the sustained rise in cases to unaltered mosquito behavior, compounded by favorable breeding conditions and pre-existing viral presence.
Entomologist Dr GM Saifur Rahman said: “We saw till 2013 that dengue patients were found in March-April. From 2013 to 2016, dengue patients were found in almost every month except two months. From 2016 onwards, the number of patients surged dramatically.”
He also said that the breeding of Aedes mosquitoes increased recently. As the rainy season is getting longer, the breeding season is getting prolonged as well.
Dengue outbreaks are usually supposed to decrease in September, but last year it was prolonged till November, which is also the case for this year as well.
A recent post-monsoon (last year) survey of the DGHS mentioned that the presence of Aedes mosquitoes is more in Dhaka South compared to Dhaka North.
Among the houses where Aedes mosquitoes were found, 39.8% were high-rise buildings and 32% were under-construction buildings.
Patient management
With 1,554 fatalities reported this year, the highest death toll in Bangladesh's history since the first detection in 2000, the country is also struggling to control the number of deaths.
Notably, deaths due to dengue peaked in September 2023, with 396 fatalities in a single month, an unprecedented occurrence in Bangladesh.
Health experts underscore the importance of effective patient management to mitigate the impact, as mosquito control efforts prove to be time-consuming.
Public health expert Dr Mushtaq Hossain said that the number of fatalities would be lower if the patients were managed in a better way.
“The reality is mosquito control is quite time-consuming. The peak point was in October last year. I fear that it may last till November. Then it might decrease,” he added.
What experts say
Recognizing the gravity of the situation, public health experts advocate for the formulation of a national strategy with targets for dengue control by 2030, backed by adequate funding.
Former director of the Department of Health and public health expert Dr Be-Nazir Ahmed said: “What we can understand from this situation is that dengue will remain throughout the year.”
He also cautioned that relying on vaccination would be realistically difficult.
“So far, no vaccine has been developed that can protect all people. Even if a vaccine is developed, it will be difficult to reach 180 million people. We saw that during Covid-19 pandemic,” Dr Be-Nazir added.
Professor Dr Ahmadul Kabir, Additional Director General of the Department of Health, said: “We are a direct victim of climate change. Even as November and December go by, we don't see any sign of the temperature dropping.”
He also said that the number of patients across the country as it is at present has never been seen before.
“If we can't fix the strategy, the rate of infection will be much higher in the future. Now there are fewer patients in Dhaka and patients are decreasing outside Dhaka as well. Expect a lot to come down in the next two weeks,” he added.