KUALA LUMPUR: Dengue cases could see a downward trend after the Health Ministry kicked off its programme to release Aedes mosquitoes infected with the Wolbachia bacteria in an effort to eliminate the disease.
Being the second country to use the biocontrol strategy after Australia, this programme follows a successful pilot project in 2017 carried out in eight areas in Selangor that showed reductions of between 50% and 80% in dengue cases in each location.
Health Minister Datuk Seri Dr Dzulkefly Ahmad said releasing Wolbachia-infected mosquitoes could also reduce dependence on the use of insecticides to control the mosquito population.
“Insecticides may have side effects,” he said.
The Wolbachia bacteria stops the dengue virus from replicating, making the mosquito unable to spread the virus when it bites.
This new dengue-fighting strategy involves placing containers with Aedes mosquito eggs injected with the bacteria at 11 locations in Kuala Lumpur, Putrajaya and Selangor before releasing the hatched insects in phases.
When the infected mosquitoes mate with wild, uninfected ones, they are likely to produce Wolbachia-infected offspring or lay eggs that will not hatch.
For example, when an infected female mosquito mates with an uninfected male, they will produce Wolbachia-infected mosquitoes.
It is the same when both infected mosquitoes mate.
But when a Wolbachia-infected male mosquito mates with an uninfected female, the eggs will not hatch.
The bacteria does not pose any danger to humans.
The Health Ministry is expected to extend the programme to other states by September.
“While the ministry is taking every effort to fight dengue, residents should continue to destroy potential Aedes breeding grounds in their areas,” Dzulkefly said at the launch of the programme at Apartment Sri Rakyat in Bukit Jalil where 35 cases of dengue were detected last year.
Residents there also had to deal with at least three episodes of the disease this year with 15 cases recorded.
Between 2014 and 2018, the area had 123 cases.
Dzulkefly also said that there was a 92.4% increase in dengue cases nationwide in the first six months of this year.
“There were 62,421 dengue cases between Jan 1 and June 29 with 93 deaths compared to 32,435 cases with 53 deaths in the same period last year,” he said.