Medical professionals urged to beware of dengue mimicry in silent spread across Malaysia
Medical professionals have been reminded to maintain a high index of suspicion for dengue, as the mosquito-borne virus often presents with misleading symptoms or none at all.
Experts said dengue is now endemic in Malaysia and not seasonal, with cases occurring year-round across all states. Yet its ability to mimic other viral infections — such as influenza — and that up to 75 per cent of infections may be asymptomatic make early detection difficult.
During a recent panel discussion on dengue, Prof Dr Zulkifli Ismail, chairman of Dengue Prevention Advocacy Malaysia (DPAM) and consultant paediatrician and paediatric cardiologist at KPJ Specialist Selangor Hospital, shared a case where a patient presented with high fever, body aches, and dehydration — symptoms that initially pointed to dengue, despite two negative test results. The diagnosis was later confirmed to be influenza.
In other instances, actual dengue cases were “misdiagnosed” or downplayed as a “common fever” and only identified after the patient’s condition deteriorated.
“I think we should not use the word ‘misdiagnose’ because dengue is quite a complicated disease actually because it can mimic other diseases,” said Dr Koh Kar Chai, past president of the Malaysian Medical Association (MMA) and chairman of DPAM’s End Dengue Deaths (ENDD) campaign.
“It comes with different representations, so it needs a very high degree of suspicion on the part of the medical practitioner. I think patients play an important role as well. They should not be complacent and say it’s a normal fever,” Dr Koh added.
Dr Zulkifli urged clinicians to keep their differential diagnoses open. “You cannot make a diagnosis just by looking at the patient or asking questions. That’s why the NS1 test is useful — it’s simple, available, and provides results within minutes for a small fee,” he said.
“What we encourage is for all doctors who have that (NS1 antigen test) in stock to use it early. It’s easier to manage when you can detect early because you know when to intervene by looking at subsequent blood tests,” he added.
Dengue No Longer Seasonal, With Cases Every Day
Dr Zulkifli said dengue is no longer confined to outbreaks every few years.
“In the early 80s, when I first started work, we used to see dengue as a seasonal thing which occurs every four years. We used to joke how it coincided with the World Cup. But of late, it hasn’t been every four years. Every year there’s dengue, and it’s not just here — Thailand, the Philippines, Indonesia are all saying the same thing.
“And when you look at the map, you look at dengue, you look at the red spots, it was originally from Southeast Asia, and now it’s everywhere. It’s in South Asia, you can see it in Miami, you can see it in Brazil, so the whole world is almost red now. That’s how it has spread and that’s why even the World Health Organization (WHO) listed dengue as one of the 10 threats to global health in 2019,” Dr Zulkifli said.
Prof Dr Zamberi Sekawi, clinical microbiologist at Universiti Putra Malaysia, described dengue as a “hyper-endemic”, noting that cases occur daily across the country — not just during perceived outbreaks.
“We see cases every day. Every now and then, you will see outbreaks. I think that is the misconception you see, that outbreak is what you perceive as seasonal. I hope that will correct the misconception,” Dr Zamberi said.
Vaccination: An Important Shield Against Severe Dengue
Dr Zamberi, who also chairs the Dengue Vaccine Position Paper committee, said vaccination remains a vital tool in the fight against severe dengue.
He highlighted TAK-003, a dengue vaccine currently available in private clinics and hospitals in Malaysia, which has demonstrated over 80 per cent effectiveness in preventing symptomatic dengue and more than 95 per cent effectiveness in reducing hospitalisation within the first year after vaccination.
“This vaccine has a strong safety profile, backed by 4.5 years of clinical study,” Dr Zamberi said. Common side effects include mild pain or redness at the injection site, while serious adverse reactions such as anaphylaxis are extremely rare. Patients are advised to remain at the clinic for at least 15 minutes after vaccination for observation.
TAK-003 has been used in several dengue-endemic countries, including Indonesia, Brazil, and Vietnam. In East Kalimantan, Indonesia, over 8,800 school children have received the vaccine. In Vietnam, one vaccination centre recorded 150,000 doses administered nationwide within just three months.
“Vaccination doesn’t just help prevent symptomatic dengue, it helps keep people out of hospitals,” Dr Zamberi said. “Everyone aged four and above should seriously consider getting protected.”
When asked by CodeBlue about plans to include the dengue vaccine in Malaysia’s National Immunisation Programme (NIP), Dr Zulkifli said there is no current update. He acknowledged that vaccine adoption in Malaysia has historically taken time, citing delays in the inclusion of pneumococcal and rotavirus vaccines.
However, he and other panelists continued to encourage uptake of the dengue vaccine to build community protection and support efforts to reduce severe disease burden.
Category: MJN enews
