A sharp rise in influenza cases has gripped Thailand in the early months of 2025, with the Public Health Ministry reporting a staggering 107,570 infections and nine fatalities so far this year. The weekly number of new patients has climbed to approximately 15,000, a significant jump from the 10,000 recorded during the same period in 2024, according to Dr Jurai Wongsawat, spokesperson for the Department of Disease Control (DDC). This alarming trend, particularly affecting children, has prompted urgent calls for stricter preventive measures in schools and renewed emphasis on annual vaccinations.
Children Bear the Brunt of the Outbreak
The data reveals a troubling pattern: children aged five to nine years are the most affected, followed by those under four and adolescents aged 10 to 14. The dominant strain driving this surge is A/H1N1 (2009), a variant known for its rapid transmission in close-knit environments such as schools, prisons, and military camps, which have reported the highest infection rates. Dr Jurai noted that the nine fatalities ranged in age from 11 to 86, with all victims having been vaccinated against the flu—a detail that raises questions about vaccine efficacy or the severity of underlying health conditions among the deceased.
“Statistics show that the flu is spreading rapidly among children,” Dr Jurai said. “It is recommended that schools enforce strict measures to curb infections. If a child is diagnosed with the flu, they should stay home for at least 3-5 days to prevent further spread” (The Nation, 20 February 2025). 
The geographical spread of the virus is equally concerning, with northern provinces like Phayao, Lamphun, and Chiang Rai topping the list of most-affected areas, alongside tourist hubs such as Phuket and urban centres like Bangkok. This distribution suggests that both rural and densely populated regions are vulnerable, potentially straining local healthcare systems already burdened by seasonal illnesses.
Post-Covid Environment and Climatic Factors
Health officials attribute the rising trend of influenza cases to a combination of environmental and societal factors. Since the relaxation of Covid-19 measures, which previously curbed the spread of respiratory illnesses through masks and social distancing, influenza has made a steady comeback. Dr Jurai highlighted that last year’s prolonged cold weather further exacerbated the situation, creating ideal conditions for viruses to thrive. While specific weather data for 2025 is not yet fully available, the persistence of similar climatic patterns could be contributing to the current outbreak.
This resurgence serves as a stark reminder of the fragility of public health gains made during the pandemic. With fewer preventive habits in place, Thailand’s population—particularly its youngest members—appears more exposed to seasonal viruses than in previous years. The challenge now lies in balancing a return to normalcy with the need for vigilance against infectious diseases.
Urgent Calls for Vaccination and School Protocols
In response to the outbreak, health authorities are urging annual influenza vaccinations, especially for high-risk groups. These include children aged six months to two years, pregnant women, seniors over 65, individuals with obesity, and those with chronic health conditions. Dr Jurai stressed that vaccination remains a critical line of defence, even as the fatalities among vaccinated individuals prompt further scrutiny of vaccine effectiveness against evolving strains.
Beyond individual action, schools are being called upon to play a pivotal role in containing the virus. Enforcing isolation periods for infected students, improving hygiene practices, and monitoring symptoms could significantly reduce transmission rates in educational settings. However, implementing such measures across Thailand’s diverse and often under-resourced school system poses logistical challenges, particularly in rural areas like Phayao and Nan, which are among the hardest hit.
A Growing Public Health Concern
The influenza outbreak of 2025 is not merely a seasonal nuisance but a growing public health concern that tests Thailand’s readiness to manage infectious diseases in a post-Covid world. The steady increase in cases over recent years, as noted by Dr Jurai, suggests that without sustained intervention, the country could face even larger outbreaks in the future. The concentration of infections in communal settings like schools and military camps further underscores the need for targeted strategies to protect vulnerable populations.
While the current death toll remains relatively low at nine, the rapid spread among children raises the spectre of wider societal impacts, from overwhelmed hospitals to disrupted education. For parents in affected provinces, the outbreak is a source of mounting anxiety, as they weigh the risks of sending children to school against the need for consistent learning and childcare.
As Thailand grapples with this surge, the emphasis must shift towards prevention rather than reaction. Public health campaigns to promote vaccination and hygiene could help stem the tide, but their success depends on accessibility and public trust. In provinces like Chiang Mai and Ubon Ratchathani, where cases are spiking, local authorities may need to collaborate with national health bodies to ensure vaccine supplies and awareness efforts reach those most in need.
For now, the nation watches as the numbers climb, hoping that swift action can avert a deeper crisis. The influenza outbreak of 2025 serves as a timely warning: even as the world moves beyond the shadow of Covid-19, other viruses lie in wait, ready to exploit any lapse in preparedness. Thailand’s response in the coming weeks will be a critical measure of its resilience in the face of recurring public health challenges.
