“I didn’t know a second dengue infection could be more severe, or that having hypertension could make things worse”
As dengue cases climb, Emergency Physician Dr Ganasan Chelladurai warns that people living with chronic illness may face a higher risk of severe dengue and should not wait for it to look serious.
Malaysia has recorded 56,752 dengue cases as of 13 August 2026, with 49 deaths reported as of 9 August 2026.1
The Health Ministry has linked the increase to dengue’s cyclical pattern and a change in the virus type, with DENV-3 now dominant nationwide.2 Against this rising caseload, people living with chronic health conditions may face greater risk once infected.
A 2026 study of hospitalised adults in northern Vietnam found that they were about twice as likely to develop severe dengue.³ Another study in Brazil found that, among hospitalised dengue patients aged 9 to 45, the death rate was 11 times higher in those with certain chronic conditions.⁴
“The patients I see affected most are often older adults living with obesity and diabetes. When they come to us late, management becomes much more difficult,” said Dr Ganasan, Consultant Emergency Physician.
His message for World Mosquito Day is simple: Do not wait for dengue to look dramatic before taking it seriously.
The Danger Can Begin As the Fever Falls
Dengue may begin with familiar symptoms such as fever, body aches and tiredness or lethargy. But for some, the illness may worsen just as the fever subsides.Warning signs, including persistent vomiting or diarrhoea more than three times, severe abdominal pain, spontaneous bleeding, difficulty breathing, noticeable weakness, lethargy or confusion, poor appetite or sudden deterioration, require urgent medical attention.5, 6
Dr Ganasan recalled a young man who arrived at the emergency department with vomiting, diarrhoea and exhaustion, but no fever.
Only when questioned did he mention having had a fever three days earlier. His blood pressure and platelet count were low, and testing confirmed dengue.
As an emergency physician, he often meets patients at this turning point, when worsening symptoms, bleeding or dangerously low blood pressure may require rapid treatment or intensive care.
Dr Ganasan explained that the fever can disappear just as complications begin.
In older people and those living with chronic illness, he said, deterioration may be faster and more severe.
When the Body Is Already Under Strain
In simple terms, a chronic condition can leave the body with fewer reserves to cope with an infection. Conditions such as diabetes, hypertension, heart or kidney disease and obesity have been associated with a greater likelihood of severe dengue, although the level of risk differs between conditions and individuals. 7,8,9
Dr Ganasan stressed that this does not mean everyone with a chronic condition will develop severe dengue or that otherwise healthy people are not at risk.
However, people with underlying conditions should seek medical advice early and may need closer monitoring.
One case still weighs heavily on Dr Ganasan.
A man in his early 50s, who lived with diabetes and obesity and also smoked, continued working through two days of fever and body aches because he was his family’s sole breadwinner.
By the fourth day, he could barely get out of bed, eat or drink, yet he feared that being admitted to hospital would cost him his next job and the income his family depended on.
He sought emergency care only after vomiting blood. Despite blood transfusions and intensive care, he passed away.
In a matter of days, the family lost more than a husband and father.
They lost the person they relied on every day, the plans they had built together and the sense of security they had worked hard to create for their children.
His wife was suddenly left to care for two young children without savings or a financial safety net. Dr Ganasan remembers her asking, “Doctor, I don’t know how to take care of my children. I don’t know how to move on.”
For Dr Ganasan, the case is a painful reminder that dengue’s consequences do not end with the patient. It can alter the course of an entire family’s life.
Grace’s Second Dengue Infection
Grace Ooi, 45, knows how quickly dengue can disrupt a life. Now living with diabetes and hypertension, she has had dengue twice.
She first contracted dengue in secondary school and spent several days in hospital.
Years later, when dengue struck again in 2013, the experience was far more severe, turning what she thought was a familiar illness into one of the most difficult health battles she had ever faced.
Her fever rose and fell for almost a week, and she sought care more than once before dengue was diagnosed.
By the time she was admitted, her platelet count was in the single digits. She needed a blood transfusion and spent three days in intensive care.
“I didn’t know a second dengue infection could be more severe, or that having hypertension could make things worse,” she recalled.
Grace spent her birthday in the ICU, instead of celebrating with loved ones.
She was away from work for two weeks and carried a heavy sense of guilt, knowing her mother was already stretched thin caring for her unwell father.
“I wasn’t afraid for myself as much as I was afraid of leaving people behind,” she said. “That hit me the hardest.”
A previous dengue infection generally provides long-lasting protection only against the infecting virus type, not all four. A later infection with a different virus type can carry a greater risk of severe disease.5,6
Why A Shift in Virus Type Still Matters
DENV-3 is not automatically more infectious or dangerous than the other virus types. Its significance lies in population immunity: people who have not been infected with this specific virus type remain susceptible to it, and the infection could be more severe if they have been infected previously with a different virus type. 2,5
A virus type shift may leave more people susceptible and contribute to wider spread; chronic illness is a separate factor that may affect how severely an individual becomes ill.
For Dr Ganasan, whatever the circulating virus type, the clinical priority is to consider the whole person: their age, underlying conditions, previous dengue history and how quickly their condition is changing.
Protecting ourselves from dengue takes more than one measure. Removing stagnant water, covering water containers, using repellents and screens, wearing protective clothing and joining neighbourhood clean-ups all remain important.5
Dr Ganasan said vaccination can add another layer of protection by reducing the risk of dengue illness and dengue-related hospitalisation. Where appropriate, people can speak to a healthcare professional about whether vaccination is suitable for them under Malaysian guidance.10
“Dengue does not affect only the person who falls ill. The cases I have seen show how it can disrupt an entire family – the people caring for the patient, the children who depend on them and the plans they have made together,” Dr Ganasan said.
“That is why prevention matters. It is not one action, and it is not the responsibility of one household or one authority. We each need to prevent breeding, protect ourselves from bites and act early when symptoms appear.”
For people living with chronic illness, taking extra precautions is not about panic.
It is about recognising that the stakes may be higher and protecting not only their health but also their families’ security and the moments they still hope to share.
References:
- Ministry of Health Malaysia and Malaysian Space Agency. iDengue 3.0 Dashboard. Data through 12 August 2026; deaths through 9 August 2026. Accessed 13 August 2026. https://idengue.mysa.gov.my/
- Nationwide Dengue Cases Up 20.7 Pct, Says Dzulkefly. 14 June 2026. Accessed 4 August 2026. https://www.bernama.com/en/general/news.php?id=2568437
- Doan TN, Cap DM. Metabolic and cardiovascular comorbidities as predictors of severe dengue in Vietnamese adults: a retrospective study, 2022–2024. Osong Public Health Res Perspect. 2026;17(2):136–144. Adjusted odds ratio for any pre-existing comorbidity: 2.06 (95% CI 1.20–3.53). https://doi.org/10.24171/j.phrp.2025.0316
- Werneck GL, Macias AE, Mascarenas C, et al. Comorbidities increase in-hospital mortality in dengue patients in Brazil. Mem Inst Oswaldo Cruz. 2018;113(8):e180082. Crude relative mortality risk: 11 (95% CI 9–15) among hospitalised dengue patients aged 9–45 with common comorbidities versus those without. https://doi.org/10.1590/0074-02760180082
- World Health Organization. Dengue and severe dengue: questions and answers. Updated 2 October 2024. Accessed 12 August 2026. https://www.who.int/news-room/questions-and-answers/item/dengue-and-severe-dengue
- World Health Organization. Dengue fact sheet. Updated 21 August 2025. Accessed 12 August 2026. https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue
- Tsheten T, Clements ACA, Gray DJ, et al. Clinical predictors of severe dengue: a systematic review and meta-analysis. Infect Dis Poverty. 2021;10:123. https://doi.org/10.1186/s40249-021-00908-2
- Ng WY, Atan R, Mohd Yunos N, et al. A double whammy: the association between comorbidities and severe dengue among adult patients—a matched case-control study. PLOS ONE. 2022;17(9):e0273071.
https://doi.org/10.1371/journal.pone.0273071
- Chen CY, Chiu YY, Chen YC, et al. Obesity as a clinical predictor for severe manifestation of dengue: a systematic review and meta-analysis. BMC Infect Dis. 2023;23:502. https://doi.org/10.1186/s12879-023-08481-9
- National Pharmaceutical Regulatory Agency. Facts About Dengue Vaccination: Frequently Asked Questions. Revised 9 February 2024. Accessed 4 August 2026. https://www.npra.gov.my
Disclaimer: The information provided in this article is for informational purposes only and should not be considered as medical advice from Motherhood. For any health-related concerns, it is advisable to consult with a qualified healthcare professional or medical practitioner.
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