Soaring cases, strained resources: A look at govt's dengue prevention strategy

The prevalence of dengue in Bangladesh has evolved from a seasonal concern to a year-round issue. Initially confined to Dhaka city, the disease has now permeated across the entire country, reaching even the remote villages.

In 2023, the number of dengue cases and deaths in the country exceeded the 23-year record. Among them were 166 children under 15 years of age.

Families face emotional and financial stress due to the loss of loved ones and medical expenses. 

The situation is worsened by a blame game among government agencies, experts said.

The health ministry argues that its role is treating patients, not mosquito control, while city corporations dispute health department data and focus on downplaying patient numbers in their respective areas. 

Besides, they said the absence of local government representation in dengue control discussions further hampers coordination. 

In the midst of this, a positive aspect is that the health ministry is drafting the National Dengue Prevention and Control Strategy (2024-2030) for the first time.

However, experts doubt the strategy's efficacy, citing an imbalance between curative and preventive measures. As dengue is a vector borne disease, they feel that this plan will not be very effective if vector control and prevention are not emphasised.

Dr Be-Nazir Ahmed, former director of Disease Control at Directorate General of Health Services, told The Business Standard, "Our main problem is that we are not trying to prevent dengue. Treating patients is not as challenging. More emphasis should be placed on prevention."

Bangladesh became the first country in the world to eradicate black fever in 2023. The health ministry worked alone to eradicate black fever, he said.

The health ministry needs to build significant capacity to eliminate dengue, the professor said. "This requires increased funding and the hiring of more staff."

"We have effectively tackled black fever and malaria with Global Fund support, but the attention and resources for dengue remain insufficient," Dr Be-Nazir added.

Brief history of dengue in Bangladesh

Dengue was first recorded in the 1960s in erstwhile East Pakistan and was known as "Dacca fever". First outbreak of dengue reported in Bangladesh during June to October 2000. 

Bangladesh has been experiencing episodes of dengue fever every year since 2000. All four serotypes have been detected. Since 2010 cases of dengue appear to coincide with the rainy season from May to September and higher temperatures. 

In 2019, there is another upsurge. In 2022 and 2023, the reported cases and deaths crossed all the previous records (2022: cases – 62,382; deaths 281 and 2023: cases 32,1179; deaths 1,705)

In winter, the incidence of dengue usually decreases. Because of this, the number of patients is slightly lower than at other times of the year, but still an average of one person dies of dengue every day. 

Earlier, dengue deaths were less in January. In 4 days of this year, 290 people were admitted to the hospital due to dengue and three people died.

Experts have been saying since last year that the dengue situation will worsen this year. In the meantime, the results of the latest post-monsoon mosquito survey of the Health Department also indicate that. 

The mosquito survey conducted on 8-18 December revealed that the presence of Aedes larvae in two cities of Dhaka has tripled compared to last year's post-monsoon period.

Wait for vaccine?

Vaccination has already started in countries where dengue prevalence is high like Bangladesh. But wait for a suitable vaccine for mass use may be somewhat longer for low and middle-income countries.

While cost remains a key concern, trials still remain incomplete for vaccine candidates designed to prevent all four serotypes of dengue to both previously-infected and yet uninfected individuals.

Dengue is present in countries with half of the world's population, with Asia accounting for 70% of all cases. Though the World Health Organisation has so far approved only two vaccines – Dengvaxia of French drugmaker Sanofi Pasteur, and Qdenga developed by Japan's Takeda Pharma – both are meant for those with previous dengue infection.

Dengvaxia is approved in the USA and about 20 countries in Europe, while Qdenga got approval in Indonesia, Brazil and some other European countries including the UK.

Brazilian city Dourados on 3 January launched a mass dengue vaccination campaign, targeting 1,50,000 people aged 4-59, the dengue vaccine will be administered in two doses, 3 months apart.

GlobalData's Price Intelligence says Qdenga costs between $95 and $158 in Europe and Australia. 

An article in Pharmaceutical Technology says Japan's Takeda chief executive hinted at significantly lowering Qdenga prices for emerging markets. The vaccine is being supplied at a lower price in Brazil, while Indonesia is expected to get it at a third of European price. The article suggests that international supports like the one GAVI had for Covid-19 vaccination could help countries like Bangladesh to include dengue vaccine in the national immunization system. 

Countries are trying to have their own vaccine for dengue. 

India's Serum Institute of India is advancing with its candidate Dengusiil, while Indian Immunologicals Limited expects to commercially launch its dengue vaccine by early 2026.

Bangladesh's leading health research firm icddr,b is working with Larner College of Medicine at the University of Vermont (UVM), USA to develop a single-dose tetravalent dengue vaccine candidate TV005. 

In September last year, the second phase trial of the dengue vaccine was successful for the first time in Bangladesh. The vaccine has shown success in generating antibodies against all four types of dengue virus.

Researchers then said the significance of TV005 is that it is single-dose and shows immune responses to all four of the dengue serotypes. 

Dengvaxia is a three-dose and Qdenga a two-dose vaccine. 

icddr'b and UVM researchers hoped their vaccine would contribute to dengue prevention in Bangladesh and South Asia. 

But it is not yet known when it will be able to hit the market.

Dengue control strategy

The draft of the National Dengue Prevention and Control Strategy says prevention and control strategies must include vaccines as an important element to anticipate and prepare for. 

Besides, there is a need for the integration of vaccines with other tools for dengue prevention and control, and investments in surveillance systems and safety monitoring of vaccines. 

It calls for the implementation of six strategies. 

These include- enhance capacity of doctors, nurses and hospitals; establish strong surveillance (disease & vector); ensure multi-sectoral participation; effective community engagement; early case detection; and prompt and effective case management.

Khabirul Bashar, medical entomologist and professor of zoology at Jahangirnagar University, told TBS, it is not enough to create a strategic plan, it should be implemented properly.

"For successful implementation of the strategy, the local government is a crucial player. Results will be achieved if the health ministry collaborates with the local government ministry," he opined.

He mentioned that there is a shortage of manpower. "Local government ministries should offer personnel, pesticides, machinery, and training to address the dengue issue."