PETALING JAYA, June 6 — Public health experts have warned that Aedes aegypti mosquitoes are becoming more resilient and efficient in spreading dengue, as Malaysia recorded a 17 per cent increase in dengue deaths last year.
The country reported 122,323 dengue cases and 117 deaths in 2024, according to Ministry of Health (MOH) data — a 0.53 per cent decrease in cases but a 17 per cent increase in fatalities compared to the previous year. Dengue was the third most common communicable disease in 2023, after Covid-19 and hand, foot and mouth disease (HFMD).
Prof Dr Zulkifli Ismail, chairman of Dengue Prevention Advocacy Malaysia (DPAM) and consultant paediatrician and paediatric cardiologist at KPJ Specialist Selangor Hospital, said that traditional control methods such as fogging are becoming less effective, and called for greater public participation in environmental cleanliness and prevention efforts.
“Fogging kills the flying mosquitoes, but not the eggs. It also kills a lot of other things like tadpoles and frogs. That’s why all these years of fogging haven’t really done much to reduce the incidence of dengue,” Dr Zulkifli said at the launch of the End Dengue Deaths (ENDD) campaign last May 22, led by DPAM, in association with Immunise4Life (IFL).
The event was officiated by Dr Ismuni Bohari, deputy director-general of health (public health), on behalf of Deputy Health Minister Lukanisman Awang Sauni.
Prof Dr Zamberi Sekawi, clinical microbiologist at Universiti Putra Malaysia and DPAM dengue vaccine position chairman, said that Aedes mosquitoes are intermittent feeders, allowing them to infect multiple people in a short time.
“These mosquitoes have always been smart. They are what we call intermittent meal takers, meaning when they feed on someone, they won’t take a full meal, unlike other mosquitoes that take one bite until they’re full, then fly away.
“But for mosquitoes like Aedes, it takes up to five people. It bites one person for one to five seconds, then moves to another. So that’s a very efficient way of spreading the virus,” Dr Zamberi said.
“The second thing is that the eggs are very resistant to drying, meaning when they lay eggs and there’s no more water, the eggs can withstand up to six months. All it needs is just a bit of water, and the eggs will hatch and breed mosquitoes.”
Dr Koh Kar Chai, past president of the Malaysian Medical Association (MMA) and chairman of the ENDD campaign, said increasing resistance to fogging chemicals indicates that the mosquitoes have evolved.
“These mosquitoes have been smart all the way through, but what we’re seeing now is resistance. Even with fogging, we find that it’s not having the desired effect,” Dr Koh said.
New Technologies And Community Action Key To Dengue Control
With conventional measures falling short, Malaysia is turning to new approaches, including the release of Wolbachia-infected mosquitoes and genetically modified mosquitoes.
Dr Zulkifli said the Wolbachia method, which has been implemented in over 10 localities, has proven effective in reducing dengue cases by 50 to 80 per cent. Dr Zamberi added that genetically modified mosquitoes, which are sterilised to prevent reproduction, are also being explored.
Dr Benedict Sim, infectious disease consultant and representative of the Malaysian Society of Infection Control and Infectious Diseases (MyICID), said entomological investigations following dengue deaths often reveal multiple breeding grounds.
“When there’s a dengue mortality, there is always a big discussion at the state level. Public health officers will begin surveying the surroundings to determine where they think the person contracted the virus or was bitten by the mosquito, and entomologists will sample water collection areas to identify how many breeding sites there are.
“It’s almost inevitable that for every dengue death, when they go around looking, they find a lot of breeding grounds for the dengue virus,” Dr Sim said. “It almost always happens in areas where people have left rubbish, tyres, or abandoned cars — or in places where clean water collects and mosquitoes can breed.”
Experts say many households overlook water collection outside the home, which remains a major source of mosquito breeding. They also urge local councils and event organisers to reduce the use of single-use plastics to prevent improper waste disposal that can create breeding sites.
Dr Sim stressed that the presence of Aedes mosquitoes in any area should be taken seriously. “If you see Aedes mosquitoes, it means there’s a breeding ground nearby,” he said. “Each of us has a role to play at home, in the neighbourhood, or in the workplace.”
Dengue Strikes Families, Not Just Individuals
At the launch of the ENDD campaign, organisers screened a video featuring dengue survivors to highlight the far-reaching impact of the disease. A recurring theme that emerged was that dengue rarely affects just one person in a household — it often strikes multiple family members at once.
Julaikha was six years old when she contracted dengue. At the same time, both her parents were also infected and hospitalised. Her mother was admitted to the intensive care unit (ICU) in critical condition.
Too young to fully understand the situation, Julaikha was separated from her parents and placed in the care of her aunt. “No child should have to go through that,” she said.
Another survivor, Jovita, was admitted to hospital with elevated liver enzyme levels due to dengue. But her biggest concern was not her own condition as her mother was also warded in the ICU with multi-organ failure from severe dengue.
“Doctors told us she might not make it. It was a nightmare,” she said. “Thankfully, we both survived, and I’m grateful to the doctors who treated us. But the experience left us drained — physically, mentally, and emotionally.”
Firdaus shared the most tragic account, having lost both his parents to severe dengue within days. “People think dengue is just a fever. But for me, it took both my parents — just like that,” he said.
Dr Sim said severe dengue can affect anyone, and managing critical cases remains difficult. “Despite the best medical efforts, severe dengue can be fatal. Prevention is always better than cure,” he said.
Dr Sim also addressed common misconceptions about the disease. “Many people think once you’ve had dengue, you’re protected. That’s not true. There are multiple dengue virus serotypes, and reinfection can actually increase your risk of severe disease,” he said.
He added that another false belief is that only older or vulnerable individuals are at risk. “In fact, nearly 45 per cent of dengue deaths in 2023 occurred among adults aged 20 to 49,” he said.
National Campaign Targets Zero Dengue Deaths
The DPAM recently launched the ENDD campaign, aiming to mobilise public awareness and action. The campaign aligns with the World Health Organization’s (WHO) goal of zero preventable dengue deaths by 2030.
Dr Zulkifli said DPAM supports the MOH’s dengue control efforts by engaging policymakers, health care professionals, and the public.
“We’ve been empowering health professionals through workshops, and now we’re turning to the public through the ENDD campaign,” he said. “Every death from dengue is a preventable tragedy.”
Dr Koh, who chairs the ENDD campaign, outlined four key steps for the public: destroy mosquito breeding sites, prevent mosquito bites, get vaccinated, and seek early treatment.
“These steps can truly save lives,” Dr Koh said. “The community must act. Together, we can break the chain of transmission.” Information on dengue prevention is available in Bahasa Malaysia and English via the campaign’s website at enddenguedeaths.dpam.org.my.
