KUALA LUMPUR: There will be a surge in dengue fever cases by the year end based on the trend over the last decade, says a Health Ministry (MoH) public health medical specialist Dr Wan Ming Keong.
He reveals that this pattern typically reaches its peak every four to five years and is 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,” Dr Wan explains to Bernama in an interview.
However, he says, patients who recover from each serotype will gain lifelong protection against that specific serotype, limiting the maximum number of dengue infections a person can experience in their lifetime to just four times.
Nevertheless, patients who contract dengue for the second time will face more severe and serious complications.
He further points out that last year, there was no reported serotype change from DENV-3 to DENV-4. However, the situation has 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,“ explains Dr Wan, who serves in the Disease Control Division of the MoH.
He says another reason for the increase in dengue cases was that only one in four dengue patients displays symptoms, while others remain asymptomatic.
“For those who are asymptomatic, they 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,” he explains.
Subsequently, the virus they ingest will spread in the new area when Aedes mosquitoes bite other hosts, he adds.
Cumulative reported cases as of epidemiological week 36 total 82,485 cases, marking an increase of 43,297 cases. This is a 110 percent spike compared to the same period last year.
Meanwhile, cumulative deaths stand at 59 deaths compared to 24 deaths for the same period last year.
To keep the situation under control, MoH is enhancing the capabilities of district health offices and state health offices in managing this 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,“ says Dr Wan.
In the meantime, MoH is collaborating with relevant agencies to support dengue control and prevention activities.
“One example is the nationwide Gotong Royong Mega Perangi Aedes, held twice a year,“ he states.
MoH is also releasing Wolbachia-carrying Aedes mosquitoes in 28 locations across seven states to enhance dengue prevention and control efforts. - Bernama
