The True Story: Flu Leads All Viruses Before Term Starts

On 12 March 2026, the Gwangju Metropolitan City Health and Environment Research Institute reported February 2026 data showing flu had an average weekly detection rate of about 20.8%, the highest of the viruses tracked, against 36.1% nationally, followed by COVID-19, rhinovirus and RSV.

Jung Hyuncheol, the institute's director, warned that students returning to school and taking part in group activities could raise the risk of spread, and urged handwashing, cough etiquette, ventilation and annual vaccination.

The Key Lesson: Group Activities at Term Start Accelerate Spread

International schools have many group activities, clubs and students who travel abroad in the holidays. Points to watch are:

• Students returning from abroad after the holidays
• Music rooms and wind instruments that are shared
• Gyms and changing rooms used all day
• Libraries and computer rooms with shared keyboards
• School buses shared morning and evening

How Flu Spreads

According to the World Health Organization, seasonal influenza spreads easily where people gather, such as schools and nursing homes. It spreads through droplets when people cough or sneeze, and through hands that touch contaminated surfaces and then the eyes, nose or mouth. Most people recover within a week, but young children, older adults, pregnant women and people with chronic illness are at risk of severe disease. Influenza is an enveloped virus, which suitable disinfectants can inactivate.

Risk Register for International Schools

1. Sick students back from abroad attend at once: likelihood medium / impact high / level high. Mitigation: ask parents to watch symptoms before term. Owner: school nurse
2. Shared wind instruments and microphones: likelihood high / impact medium / level high. Mitigation: provide personal instruments or disinfect after use. Owner: music teacher
3. Computer keyboards not wiped: likelihood high / impact low / level medium. Mitigation: wipe after every period. Owner: IT staff
4. Damp changing rooms: likelihood medium / impact medium / level medium. Mitigation: clean daily and ozone-treat on a schedule. Owner: facilities team
5. No plan when several students in a class fall ill: likelihood medium / impact medium / level medium. Mitigation: notify parents and fog the classroom at once. Owner: head of school

Ways to Reduce Flu Risk in International Schools

1. Communicate with parents before term
2. Screen symptoms in the school clinic
3. Wash hands before and after group activities
4. Wipe keyboards and instruments after use
5. Ventilate classrooms and gyms
6. Hold a vaccination day at school
7. Fog and ozone-treat before term and after cases

How ULV Disinfection Fogging Helps

The World Health Disinfection disinfection service uses ULV fogging machines that turn the disinfectant into a fine mist. It settles across the whole area, including corners, curtains, upholstery and surfaces that hand wiping cannot reach.

• Whole-area coverage without relying on wiping spot by spot
• Quick return to use, typically about 30 minutes after fogging
• Uses Chemgene HLD4H, which meets EN 14476 for virucidal activity according to the product page
• The team wears full protective equipment, so owners and staff do not take the risk themselves
• Report and photos after the job for customers, management or authorities
• Tax invoice with 3% withholding tax for companies and agencies

Ozone Treatment for Closed Rooms and Stuffy Spaces

The World Health Disinfection ozone treatment service uses machines that generate ozone gas from oxygen in the air. It suits closed rooms such as meeting rooms, bedrooms, classrooms, sick bays and vans, helping reduce germs in the air and on surfaces and removing stale odours. Ozone breaks back down into oxygen after treatment, leaving no residue.

• Works alongside disinfection fogging: spray or wipe surfaces first, then use ozone for the air and corners of closed rooms
• No people or pets in the room during treatment: the team seals the room and runs a timer
• Ventilate after treatment before normal use resumes
• Machines tested by Intertek, according to WHD's service page
• Ideal after someone has been ill, such as recovered patients' rooms, shared bedrooms and shuttle vans

Before and After

Frequently Asked Questions

Q: How much flu was there in Korea in early 2026? A: Gwangju found an average weekly detection rate of 20.8%, and 36.1% nationally, in February 2026.

Q: When should a school be fogged? A: Before term, during holidays, and right after several students fall ill; areas can usually be used about 30 minutes after fogging.

Q: Does the fogging disinfectant work on flu? A: The team uses Chemgene HLD4H, which meets EN 14476 for virucidal activity according to the product page, and influenza is an enveloped virus that suitable disinfectants can inactivate. Fogging does not replace vaccination or handwashing.

Q: Can I enter the room right after ozone treatment? A: No one should be in the room during treatment. Ventilate afterwards before normal use; the team will advise the right time for the room size.

Q: Can international schools get a tax invoice? A: Yes. Tax invoices are issued and 3% withholding tax is supported. Call 065-556-6294 or LINE @whd268.

Related Links and Sources

• World Health Disinfection disinfection service
• World Health Disinfection ozone treatment service
• Chemgene HLD4H disinfectant and price
• Influenza information from Thailand's Department of Disease Control, hotline 1422
• WHO seasonal influenza fact sheet

Prevent Flu with Disinfection Fogging and Ozone Treatment

The true story from Gwangju shows term start is a risky time. Prepared schools let students begin the new term without whole classes on sick leave. Reduce the risk with the World Health Disinfection disinfection service for classrooms, gyms and libraries, and the ozone treatment service for music rooms, changing rooms and the school clinic. To book, call 065-556-6294 or LINE @whd268.

Call 065-556-6294 | LINE: @whd268