PETALING JAYA: National dengue numbers have overtaken last year’s full total.
Health experts warn that El Nino weather patterns and the dominant DENV-3 strain will trigger further severe infections.
According to the Health Ministry’s iDengue portal, cases reached 55,855 as of Tuesday, slightly exceeding 2025 recorded cases that stood at 55,399.
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They said warmer temperatures during El Nino can accelerate mosquito development, allowing the virus to replicate faster.
Public healthcare specialist Prof Dr Sharifa Ezat Wan Puteh of Universiti Kebangsaan Malaysia said dengue was associated with the El Nino-Southern Oscillation (ENSO), and cases were expected to spike.
“Dengue is already endemic in Malaysia and with the four serotypes now co-circulate, this makes Malaysia hyperendemic.
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She said dengue affects both rural and urban areas, particularly densely populated and developed areas.
Prof Sharifa Ezat added that particular attention was now being focused on DENV-3, which has emerged as a dominant serotype in Malaysia.
“It is associated with more cases and deaths, as previous infections with strains such as DENV-1 and DENV-2 do not provide protection against DENV-3, meaning those previously infected may still be vulnerable.
“On the other hand, it can trigger a serious immune response and may lead to dengue haemorrhagic fever,” she said.
Prof Sharifa Ezat said people should clean their surroundings and prevent breeding sites, as mosquito larvae could breed in containers around homes, workplaces and schools.
“Those who may develop symptoms such as fever, rashes, bleeding tendency, myalgia, joint pain and headaches should seek doctor’s help to determine whether it is dengue or something else, as dengue can mimic other viral and bacterial infections.
“Some patients may need admission with IV fluids, or even platelet and plasma transfusions in severe cases.
“The risk of severe dengue is higher among young children, pregnant women and the elderly,” she said.
She said the tetravalent dengue vaccine Qdenga was available at certain private facilities and worked against all four serotypes.
Universiti Malaya virologist Dr Sazaly Abu Bakar said DENV-2 has been the predominant serotype in previous years and past exposure protected against severe reinfection.
However, the emergence of DENV-3 meant there was no existing immunity or protection against the serotype, he added.
“More concerning, previous infection with DENV-2 may enhance a subsequent DENV-3 infection, increasing the risk of severe dengue.
“If not treated early and appropriately, it would result in high mortality,” he warned.
Dr Sazaly said healthcare facilities needed to prepare staff to recognise severe dengue cases, stock up on ICU supplies and ensure sufficient beds.
While cases were expected to rise, he said they were unlikely to reach the more than 120,000 recorded annually in 2023 and 2024, but such levels could be seen next year or the following year.
Public health medicine specialist Datuk Dr Zainal Ariffin Omar urged the public to spend 10 minutes every week searching for and destroying mosquito breeding sites.
Other measures include keeping water containers covered and sealed, using repellent when leaving the house and wearing long-sleeved shirts and long pants during the day.
