Bangladesh must take “short and long” term plans to control dengue, an expert says, as the World Health Organization (WHO) in a wake-up call has urged the government to take “swift action”.
“We should start it now,” Prof Mahmudur Rahman, former director of the government disease monitoring agency, IEDCR, told Dhaka Tribune in an interview yesterdau.
The WHO reported that a significant surge in dengue fever cases gripped Bangladesh, calling for efforts to control the mosquito vector population and minimize individual exposure, such as by using mosquito repellents and wearing long-sleeved clothes.
With 11 more deaths reported from dengue in 24 hours till Sunday morning, the total fatalities from the mosquito-borne disease in Bangladesh rose to 398 this year. So far, the health ministry recorded 85,411 dengue cases and 75,280 recoveries this year. This is the highest in the period compared to any year. August and September are usually peak times.
Prof Rahman was the longest serving director of the Institute of Epidemiology, Disease Control and Research or IEDCR, when he retired in 2016. He sat on several expert committees of the WHO on infectious diseases.
He shared a detailed plan with Dhaka Tribune, saying that for long term action the “Wolbachia” method should be established without any delay.
“In 2019, there has been a decision to start the Wolbachia method. But it did not happen due to unknown reasons. If we could start that in 2019, this year we could expect some benefits,” he said, as 2019 was the worst year for dengue in Bangladesh’s history before this year.
According to the WHO, dengue was first recorded in the 1960s in Bangladesh (then known as East Pakistan) and was known as “Dacca fever”. Since 2010 cases of dengue appear to coincide with the rainy season from May to September and higher temperatures.
Bangladesh’s climate conditions are becoming more favorable for the transmission of dengue and other vector-borne diseases including malaria and chikungunya virus due to excessive rainfall, waterlogging, flooding, rise in temperature and the unusual shifts in the country’s traditional seasons. WHO finds.
There is no specific treatment for dengue. The timely detection of cases, identifying any warning signs of severe dengue infection such as severe abdominal pain, persistent vomiting, rapid breathing and bleeding gums or nose after fever subsides, and appropriate case management are key elements of care to lower case fatality rates to less than 1%.
Swift action
“Round the year targeted interventions involving the local elected representatives and community volunteers is the key to control the disease. Micro planning would be required for this,” Prof Rahman said.
“We have to establish a Web-based Dengue surveillance system involving the identified government, and private hospitals, and diagnostic centers. To avoid duplication telephone numbers could be used. Hospitals and diagnostic centers should be identified to represent all areas of the respective city corporations,” he said.
“The findings should be publicly made available on a real time basis. Regular reporting can be made a mandatory requirement for license renewal of hospitals and diagnostics by DGHS.”
“Establish zone wise Vector surveillance in all city corporation areas,” he recommended, adding that awareness building through mass media must be strengthened.
“Dengue management guidelines need to be followed strictly for better management of patients. This needs to be monitored through a task force,” he said.
“Strong monitoring of the quality of the diagnostic kits that are available in the market is also needed,” he said, since there are reports that patients with all the symptoms of dengue tested negative in diagnostic labs.
“At the same time, City Corporations should review their insecticide spraying policy. Time to time efficacy of insecticide needs to be tested by a third party,” he said.
“Urgent research needs to be undertaken to monitor the circulating serotypes,” he said, adding that all these actions need to be continued throughout the year,” he said.
Wolbachia
For long term action the Wolbachia method should be established, Prof Rahman said.
Wolbachia are safe, natural bacteria present in up to 50% of species, including some mosquitoes. However, Wolbachia is not usually found in the Aedes aegypti mosquito, the primary species responsible for transmitting viruses such as dengue, Zika, chikungunya and epidemic yellow fever.
According to the World Mosquito Programme, Australia, current evidence indicates that Wolbachia works in two ways within a mosquito. The first way is to boost the natural immune system of the mosquito to make it harder for the mosquito to support the dengue, Zika, chikungunya, Mayaro or yellow fever infection. If the mosquito can’t get infected, then it can’t transmit these viruses to people.
The second way Wolbachia works is by competing against viruses for key molecules like cholesterol. Both the viruses and Wolbachia need cholesterol to survive inside the mosquito. When Wolbachia is present, it consumes these molecules and makes it harder for the viruses to grow. If it’s harder for the viruses to grow, then it’s harder for them to be transmitted.
“We maintain colonies of Wolbachia carrying Aedes aegypti mosquitoes in our laboratories. We take relatively small numbers of these laboratory-grown mosquitoes and release them into a target location, where they will breed and pass the Wolbachia into the wild population. The Wolbachia will then spread and typically maintain itself in more than 90% of the wild mosquitoes indefinitely,” World Mosquito Programme said.
“It’s an effective solution globally accepted,”Prof Rahman said. “This method can protect communities from mosquito-borne diseases without posing risk to natural ecosystems.”