Influenza Surveillance and Disease Burden in Bangkok, 2020–2024: A Contemporary Analysis

Abstract

This descriptive study employed secondary data on influenza cases from 2019 to 2024, retrieved from the Digital Disease Surveillance Platform operated by the Bureau of Epidemiology, Department of Disease Control. The data were obtained by the Surveillance and Emergency Response Section, Urban Institute for Disease Prevention and Control. The objectives were to analyze the influenza situation in Bangkok and to review current control measures and provide recommendations for influenza prevention and control in the area. Data analysis was conducted using STATA version 19.

                The findings revealed that Bangkok reported the second-highest number of influenza cases nationwide, with an incidence rate of 1,856.12 per 100,000 population. The majority of cases were female (52.47%).
The highest incidence was observed in the 6–12 years age group (5,428.13 per 100,000 population), followed by the 2–5 years and under-2 years age groups (5,199.15 and 3,687.24 per 100,000 population, respectively).
The top three districts with the highest incidence rates were Ratchathewi (11,499.90 per 100,000 population), Bang Rak (10,521.50 per 100,000 population), and Phaya Thai (8,678.10 per 100,000 population). Most outbreaks occurred in schools and correctional facilities.  In 2024, the peak in influenza cases occurred from June to October, earlier than the 5-year median (2019–2023). This trend is likely associated with the early onset of the rainy season in Bangkok, as forecasted by the Thai Meteorological Department (TMD). Vaccine coverage in Health Region 13 (Bangkok) remains below the target level. Currently, the key effective measures for influenza prevention and control include social distancing, mask-wearing, and vaccination. Policy recommendations based on field assessments indicate that continued policy-level advocacy is necessary to maximize the effectiveness of influenza prevention and control measures in Bangkok.