Our dance with dengue: Missteps and knee-jerk reactions

On July 7 this year, Bangladesh witnessed its first dengue death.

Sayeeda Nasrin Bably, 35, an assistant professor of the history department at Jagannath University, who was on life support, died at the capital's Square Hospital around 4am.

Deputy Attorney General Barrister Abdullah Al Mahmoud, husband of Sayeeda Nasrin, at the time said his wife was admitted to Square Hospital with dengue fever on 20 June. The following day, she was shifted to the ICU. Later, she was kept on life support as her condition deteriorated.

Despite the evidence, officials of the Directorate General of Health Services (DGHS) claimed they were yet to receive any report of a death by dengue.

In July, dengue cases had jumped by almost 600%, with three deaths being officially confirmed.

On August 2, Bangladesh recorded the highest number of dengue patients in a single, with 287 new patients being hospitalised.

Amid the Covid-19 pandemic, the dengue disease had taken a backseat. But the menace had not disappeared; it was more likely forgotten about.

For years, experts have been saying that the main tool for controlling vector-borne diseases (VBDs) was vector control. Any other method would work only if those complemented vector control.

In 2016, Margaret Chan, former Director-General of the World Health Organization (WHO), warned the world during a famous address at the 2016 World Health Assembly on the Zika epidemic, saying it was "the price being paid for a massive policy failure that dropped the ball on mosquito control in the 1970s."

That steep price is still being paid to this day.

Always stuck in the planning stages

In Bangladesh, the war against Aedes mosquito can be termed as ineffective. It is akin to the USA's war against the Taliban in Afghanistan; the minute you rest easy on your laurels, is the minute you are most susceptible to attack.

Fines and fogging are a regular feature of anti-mosquito drives.

While both steps, along with the work being done are laudable, however, despite years of experience dealing with the dengue outbreak, Bangladesh is yet to formulate an effective vector policy.

Thus, every year the viral dengue fever has surged in the country.

In 2019 alone, one lakh people were infected with dengue and at least 179 died.

The lack of an integrated vector control policy and a research centre has only exposed the failure further.

The Mosquito Control Department in Dhaka, established in 1948 during the fight against malaria, had done some great work. It conducted extensive research, carried out drives and focused on researching mosquito control activities.

Once the department came under the purview of the LGRD in the early 80s, it seemingly lost its lustre.

Nowadays, the department offices is used as a warehouse for insecticide drums, with chemicals being the favourite options of Dhaka mayors who are leading the fight against the dengue menace.

At the end of 2019, after dengue had ravaged much of the capital, a vector management policy and modernising the Mosquito Control Department were revisited.

Two years later, only a draft on the matter had been finalised and even by July this year, it was yet to be sent public administration and finance ministries.

Revisit, revise, redesign

The fight against mosquitoes is conducted using a three-pronged approach: insecticide, pesticide fogging; awareness campaigns and fining those who create environments conducing to the breeding of Aedes mosquitoes.

In a recent initiative, Dhaka North City Corporation Mayor Atiqul Islam announced incentivising activities against mosquitoes.

"We will give Tk50 for the unused commode and discarded tires and will give Tk5 for each coconut shell, pots, and chips packet. Anyone can collect money by submitting it to the councilor office or zonal offices," said the DNCC mayor.

Meanwhile, Dhaka South City Corporation (DSCC) Mayor Sheikh Fazle Noor Taposh asked city dwellers to provide information about Aedes mosquito larvae or breeding sources on their website or control room numbers.

"We will take immediate steps to destroy the breeding sources after getting the information," he said through a video message.

In 1998, Singapore's Institute of Environmental Epidemiology, under the Ministry of the Environment, made some important findings. One of them was that there was no evidence that emergency control measures, particularly the use of chemical insecticides, are effective after cases have already been detected.

Singapore, meanwhile, had been stringent in fighting the mosquitoes, but even they, too, failed as this year the infection reemerged once again.

But, instead of doing the same thing over and over again, the Singaporean authorities acted fast and designed news way to deal with an emerging crisis.

Fogging was just one of the options there and studies show that it isn't always the best option.

According to a research published last year in the peer-reviewed journal BMC, the authors, who specifically studied the dengue fever and insecticide in Aedes mosquitoes in South Asia, concluded that, "Although insecticides were once effective in controlling mosquito-borne diseases, the increasing trends of mosquito-borne diseases may indicate an increasing resistance to or ineffectiveness of insecticides in controlling the transmission of the diseases."

They urged authorities concerned to revisit the practice and formulate new ways of dealing with the infection.

From suggesting the use of more diversified products to turning to natural mosquito predators, such as fish, water bugs and frogs, the authors stressed the need to rethink how to eradicate mosquitoes.

As for fines to the public, numerous research has shown that without the presence of constant checks, the public may not be motivated to prevent mosquito breeding.

What, however, may work, is an example from Vietnam. Closely engaging the public, stressing on how they maintain even their water storage tanks – a breeding ground for Aedes mosquito -- helped fight the infections better.

This is something that the two mayors are doing, but whether they can do it all alone is another question.

At the height of a dengue outbreak in Singapore, the country began to consider dengue as an environmental disease, with a focus on removal of water containers from in and around homes, solid waste management, and limited use of insecticides.

It also enlisted its environment ministry to engage in the battle, quickly adding more boots on the ground.

That, coupled with community engagement, proved to be a model worth replicating.

Mosquitoes without borders

Much like Covid-19, the only way to fully eradicate the threat of Aedes mosquitoes is to take a regional approach.

In a research paper by Dr Ooi, the-then program director for Biological Defense at the Defense Medical and Environmental Research Institute, Singapore, he said that, "A bolder, but possibly more rewarding, approach would be for Singapore to take the lead in strengthening disease surveillance and vector control in the Southeast Asian region, where dengue remains hyperendemic…"

He went on to say that both symptomatic and asymptomatic – and there are many – carriers of dengue who entered Singapore would only go on to spread the infections further. The constant importation of the infection would mean there would always be surges.

One country, alone, especially in such an interlinked world would not be able to stop the spread of the infection.

As Covid-19 continues to dominate headlines and discussions, it is prudent to remember that dengue remains one of the most infectious diseases in the world. It is also important to remember that there is not yet any vaccine for the infection.

Without a concentrated regional effort, the scourge of dengue will remain for many years to come.