Rising dengue burden in high-altitude central Nepal: evidence from a population-based longitudinal serosurvey,...

Area of Science:

• Epidemiology
• Infectious Diseases
• Public Health

Background:

• Dengue is a growing global health concern, exacerbated by climate change and urbanization.
• Nepal is experiencing an expansion of dengue into higher altitudes, with significant outbreaks in recent years.
• Existing surveillance methods may not fully capture the community-level burden of dengue infections.

Purpose of the Study:

• To assess the seroprevalence and seroincidence of dengue infection in a population-based cohort in Nepal.
• To identify risk factors associated with dengue seroconversion within the study population.
• To understand the changing dynamics of dengue transmission in Nepal's expanding endemic regions.

Main Methods:

• A prospective serologic cohort study was conducted in Kathmandu and Kavrepalanchok districts, Nepal.
• A representative sample of residents aged 0-25 years was enrolled and followed over multiple phases (2019-2023).
• Blood samples were collected via finger-prick and tested for dengue IgG antibodies; seroconversion rates and risk factors were analyzed.

Main Results:

• The overall seroincidence rate was 33.8 per 1,000 person-years, with significantly higher rates in urban Kathmandu.
• Dengue seroincidence increased with age and showed an upward trend from 2019 to 2023.
• Living with a dengue-positive individual and household water-filled flower basins were significant risk factors for seroconversion.

Conclusions:

• The study demonstrates a substantial and increasing burden of dengue infection in the Kathmandu Valley.
• Findings underscore the urgent need for targeted public health interventions to combat rising dengue cases in Nepal.
• The results emphasize the importance of community-level surveillance and risk factor mitigation for dengue control.