Background

Dengue is known to be a disease that disproportionately affects children, however, at both The National Hospital for Tropical Diseases in Hanoi and the Hospital for Tropical Disease in Ho Chi Minh City, more than 300 patients over the age of 60 present every year requiring admission.  

While many anecdotal reports suggest elderly patients may develop severe disease more frequently, there is limited prospective data in the literature. 

Objectives

1. To describe and compare the daily signs, symptoms, and blood tests in dengue patients aged 60 and above with those aged 18 to 30. 
2. To better understand the body’s responses to dengue infection by measuring biomarkers released over the disease course due to inflammation, immune cells activation, and blood vessel injuries; and compare these results between the two age groups.
3. To explore the innate and adaptive immune responses to dengue in both age groups.
4. To examine the effects of immunosenescensce (age-related immune dysfunction) on dengue virus levels in patients’ blood and disease severity.

Dr Nguyen Minh Nguyet said: “We want to explore how the immune system in elderly patients contributes to severe progress of disease. The outcomes of this study could inform not only improved clinical treatment guidelines for this population, but also vaccine development pathways in the future.” 

An outcome of this project is supporting Dr Dang Thi Bich from NHTD to pursue her PhD at the Hanoi Medical University (supervised by Assoc Prof Nguyen Minh Thu and Dr Nguyen Minh Nguyet). Dr Bich’s project, titled “Disease progression and the changes of biomarkers in elderly patients hospitalised with dengue with warning signs,” will use some data and samples collected in this project. Dr Bich is expected to complete her PhD in December 2027. 

Study Design

Type: Observational cohort study 

Recruitment sites: Both the general and ICU wards at the National Hospital for Tropical Diseases (NHTD) in Hanoi, the Hospital for Tropical Diseases (HTD) and Thong Nhat Hospital in Ho Chi Minh City. 

Sample size: 150 dengue patients 

• 100 elderly patients (aged 60 and above) 
• 50 younger patients (aged 18 to 30) as a control group

Data collection: 

• Daily blood samples to measure full blood cell count, liver function, renal function, viremia levels, and immune responses. 

• Point-of-care ultrasound scan (POCUS) to assess fluid accumulation in the lungs and abdomen, indicators of plasma leakage and disease severity. 

• Electrocardiography (ECG) to assess the electric functions of the heart. 

• Tracking clinical outcomes through hospitalisation and follow-up visits. 

• • 5 days during hospitalisation. 

• • Additional follow-ups on Day 30 and Day 90 since fever onset.

Status: Active and ongoing; patient recruitment and laboratory testing are in progress.   

Photo credit: Nicholas Fernandez (Fact & Fiction Films)