These Asian Countries Are Fighting Dengue in Ingenious Ways
On August 20, the world observed World Mosquito Day. The date is a commemoration of how British doctor, Sir Roland Ross, discovered on August 20, 1897 that only female mosquitos transmit malaria to humans. Over 120 years later, humans are still grappling with how to handle mosquitos.
Last week, the Philippine government officially declared Dengvaxia illegal, just as dengue cases soared to 188,000, more than twice the figure of 93,000 from August of last year. The ban was made despite the pleas of doctors from the Philippine Pediatrics Society and the Pediatric Infectious Disease Society of the Philippines for Dengvaxia to be used again.
Dengvaxia is the only vaccine against dengue, and is widely used in 11 dengue-susceptible countries such as Brazil, Indonesia, Singapore, and Thailand.
While Filipino politicians are still milking the Dengvaxia issue, other Asian countries have made strides in the fight against mosquito-borne diseases. Here are some promising solutions done by other Asian countries which the Philippines can follow.
1| Malaysia’s Anti-Mosquito Streetlamps
Malaysia has devised solar-powered and wind-powered streetlamps that attract and kill mosquitos, while providing sustainable lighting on the road.
The streetlamps are called Eco-Greenenergy Outdoor Lighting System developed by the University of Malaya in Kuala Lumpur. The streetlamps produce a fake human scent to attract mosquitos and eventually trap them by suction fan. The LED streetlamps mimic the fake human scent by combining titanium dioxide and ultraviolet light to produce CO2. The compound is irresistible to mosquitos.
“The mosquito trap takes advantage of the mosquito’s sensory abilities by tricking them with features that mimic the odors associated with humans,” says head researcher Chong Weng Tong in a report by The Guardian.
Fooled mosquitos enter the trap through capture windows. Once inside, they are sucked downward to a capture net where they are trapped.
2| Singapore’s Anti-Dengue Mosquito Army
Scientists at Singapore’s National Environment Agency (NEA) are breeding millions of mosquitos as biological weapons against dengue. It might sound counterproductive, but scientists at NEA’s lab are introducing Wolbachia bacteria into male mosquitos of the species Aedes aegypti, which is known to carry the dengue virus.
When these male mosquitos mate with their female counterparts, the resulting eggs will not hatch. Test sites in Singapore show an 80 percent reduction rate in dengue-carrying mosquitos.
The method is a masterstroke because humans no longer need to locate dengue carriers—the male of the species will already do that and infect the females with bacteria that sabotages their eggs’ viability.
Singapore’s Project Wolbachia is currently on its third phase of field study to determine if the suppression of Aedes aegypti mosquito populations can be sustained in larger areas. Tens of thousands of lab mosquitos were being released twice a week at study sites since August 5.
3| Malaysia’s Genetically Modified Mosquitos
Another promising solution to the dengue problem is Malaysia’s use of genetically modified mosquitos. Scientists concede that among all species of mosquitos, the dengue carrier species or Aedes aegypti is the most difficult to control because of its behavior and breeding patterns. Unlike other mosquitos that breed in swamps and marshes, the dengue mosquitos like to breed in small pools of clean water collected in plastic surfaces, potted plants, cans, tarpaulins, and other similar places. As adults, the mosquitoes huddle in small clusters and hide in dark areas such as behind curtains, under beds, and even laundry.
Malaysia’s genetically modified Aedes aegypti mosquitoes were developed by the University of Oxford in England and commercialized by a biotechnology company called Oxitec. The technique modifies the genes inside the male mosquitoes so that when they mate, their offspring die before they could reproduce.
Trials of the technique showed that dengue mosquito populations were reduced by 95 percent. The same technique of weaponizing mosquitos against mosquitos was tested in Brazil, Cayman Islands, and Panama where it had a similar success rate in reducing Aedes aegypti populations.
4| Taiwan’s Smart Mosquito Trap
Scientists at Taiwan’s National Health Research Institute have developed a mosquito trap powered by artificial intelligence. The smart mosquito trap is capable of identifying various species of mosquitos to determine whether they are vectors of diseases such as dengue, malaria, chikungunya, and Zika virus. Once a mosquito is trapped inside the device, the AI successfully identifies its species in just 0.07 seconds.
Taiwanese researchers built a massive database composed of tens of thousands of images of mosquito specimens. Each specimen of mosquito was photographed 10,800 times from 720 angles. The images were uploaded to the smart mosquito trap, which has an accuracy of 90 percent.
The smart mosquito traps will be installed in key places in Taiwan that are susceptible to outbreaks caused by mosquitos. Its purpose is to immediately alert the Taiwanese government to any increase in population of various mosquito species. That way, the government can act quickly before any outbreak occurs.
Local Politicians Use Frogs and Fish to Fend Off Mosquitos
Last week, Allan Franza, chair of Barangay Old Balara in Quezon City, released 1,000 frogs at a local creek to manage the mosquito populations in his community, for which he received mixed reactions. Mosquito larva and adult mosquitos are thought to be part of the bull frogs diet.
In Zambaonga City, city councilor Jihan Edding ordered 5,000 mosquitofish from Pangasinan. Mosquitofish are small freshwater fish that prey on mosquito larvae and mosquitos. They are known as one of the most voracious predators of the insects. They breed quickly and require little supervision. They plan on releasing the mosquitofish in stagnant water.
The National Government Must Take the Mosquito Problem Seriously
The efforts of local politicians to use natural methods to combat dengue is laudable, but a national crisis demands the concrete action of the national government. In July 2019, the number of dengue cases in the country was 140,000. In less than a month, that number ballooned to nearly 200,000.
The most affected age group in dengue cases are Filipino children aged 5 to 9 years old (23 percent). They are also the most affected age group in dengue fatalities (42 percent).
This is unprecedented. This is the worst dengue epidemic in the history of the Philippines.
Dengue is recognized as a notoriously tough disease to eliminate. Against it, we need a solid and effective national program that will enhance government preparedness, immunize Filipinos, and facilitate effective response to mitigate the effects of future outbreaks.