The True Story: A Strain That Travelled the World

On 17 December 2025, Brazilian media reported that Brazil's health ministry confirmed the country's first case of influenza A (H3N2) subclade K, found in samples analysed in the state of Pará, in its week-49 surveillance report.

The ministry said there was so far no evidence that subclade K causes more severe disease, and the pattern matched typical seasonal influenza A. Influenza A hospitalisations were rising or stable in several northern and north-eastern states, and vaccination remained the main way to reduce severe illness.

The Key Lesson: Travellers Carry Flu Across Continents in a Day

Hostels on Khao San Road, in Chiang Mai and on the islands host travellers from many countries every night. Points to watch are:

• Dorms of 6–12 beds sleeping close
• Shared kitchens and utensils everyone uses
• Shared bathrooms busy in the morning
• Lockers and sheets changing guests daily
• Bars and lounges where many nationalities mix

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 Hostels and Backpacker Lodgings

1. Sick guests sleep in shared dorms: likelihood high / impact high / level critical. Mitigation: offer a spare private room to sick guests at a special rate. Owner: hostel manager
2. Sheets not changed between guests: likelihood high / impact medium / level high. Mitigation: change sheets at every check-out. Owner: housekeeper
3. Shared bathrooms cleaned once a day: likelihood high / impact medium / level high. Mitigation: clean two or three times a day. Owner: housekeeper
4. Shared kitchen utensils poorly washed: likelihood medium / impact low / level low. Mitigation: post washing instructions and supply detergent. Owner: front desk
5. Dorms never disinfected: likelihood medium / impact medium / level medium. Mitigation: fog and ozone-treat dorms on a schedule. Owner: hostel manager

Ways to Reduce Flu Risk in Hostels

1. Keep a spare private room for sick guests
2. Change sheets at every check-out
3. Clean shared bathrooms several times a day
4. Install hand sanitiser on every floor
5. Hand out masks at the front desk
6. Ventilate dorms during the day
7. Fog and ozone-treat dorms on a schedule

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: What is the superflu? A: Influenza A (H3N2) subclade K. Brazil's health ministry said there was no evidence it is more severe.

Q: Where was Brazil's first case found? A: In the state of Pará, per the week-49 2025 surveillance report.

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 hostels 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 real news from Brazil shows flu travels with tourists. Hostels that care for dorms and shared spaces protect guests' health and good reviews. Reduce the risk with the World Health Disinfection disinfection service for shared kitchens, bathrooms and lounges, and the ozone treatment service for shared dorms and spare private rooms. To book, call 065-556-6294 or LINE @whd268.

Call 065-556-6294 | LINE: @whd268