DENGUE fever cases are expected to surge at the year’s end based on the trend of the last decade, a Health Ministry (MOH) public health specialist Dr Wan Ming Keong said.

He said infections typically reach a peak every four to five years, a pattern believed to be due to changing dominant serotypes in a particular area.

“The last reported peak was in 2019. We anticipate that cases will peak again by the year end or early next year. A contributing factor is the virus serotype afflicting an area.

“Dengue has four serotypes (DENV-1 to DENV-4), and whenever the dominant serotype in a particular area switches to a different one, cases increase because the local population’s immunity towards the new serotype is still low. This makes them more susceptible to the infection,” Wan said in an interview with Bernama.

Patients who recover from each serotype will gain lifelong protection against that specific serotype, limiting the number of dengue infections a person can experience in their lifetime to just four. But patients who contract dengue for the second time face more severe complications.

Wan said last year did not see a serotype change from DENV-3 to DENV-4. However, the situation changed this year.

“What we’ve observed this year is that DENV-4 has shifted to DENV-2. As long as the dominant serotypes in an area keep changing, cases will continue to persist and rise.”

He said three in four dengue patients were asymptomatic.

“Those who are asymptomatic will not seek treatment because they are unaware they have been infected. When they move to new areas, mosquitoes that do not yet carry the virus will feed on the blood of dengue-infected patients.”

This causes the virus to spread, he said.

There were 82,485 dengue cases reported in epidemiological week 36, an increase of 43,297 cases, or 110% spike compared to the same period last year.

Deaths stood at 59, more than double the 24 deaths in the same period last year.

MOH is enhancing the capabilities of district health offices and state health offices to manage the outbreak.

“For all areas affected by the dengue outbreak, we will conduct risk assessment activities related to the environment and entomology, such as relevant indices. Based on this, we will take action, including source reduction activities,” said Wan.

MOH is also working with other agencies to support dengue control and prevention activities.

“One example is the nationwide Gotong-Royong Mega Perangi Aedes, held twice a year.”

Wolbachia-infected Aedes mosquitoes have been released in 28 locations in seven states to enhance dengue prevention and control efforts. – Bernama, October 3, 2023.