The True Story: In the Tropics, Flu Comes with the Rain

Bangladeshi newspaper Prothom Alo reported on 9 September 2026 on 20 years of surveillance, which found 172,792 patients with influenza-like illness and severe respiratory infection, of whom 22,284, or about 13%, had influenza.

The data showed Bangladesh's flu season runs from April to September, peaking in June and July. Ages 5–24 were most often infected, but most deaths were in people over 60. Experts advised vaccination in March, before the season. Tahmeed Ahmed, executive director of icddr,b, contributed.

The Key Lesson: Monsoon Countries Must Prepare for Rainy-Season Flu

Thailand has a monsoon climate like Bangladesh, and the DDC notes Thai flu often surges in the rainy season. Community hospitals should watch these points:

• Outpatient rooms packed in the rainy season
• Shared wards with older patients close together
• Children's nebuliser rooms used in turn
• Damp, stuffy buildings during long rains
• Few staff for many patients

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 Community Hospitals

1. No plan for rainy-season flu: likelihood medium / impact high / level high. Mitigation: plan beds and medicines before the rains. Owner: director
2. Older people unvaccinated before the season: likelihood high / impact high / level critical. Mitigation: vaccine drive before the rainy season. Owner: family medicine unit
3. Shared wards with close beds: likelihood high / impact medium / level high. Mitigation: cohort zones for flu patients. Owner: ward head
4. Damp, stuffy buildings: likelihood medium / impact medium / level medium. Mitigation: check ventilation and exhaust fans. Owner: facilities
5. Wards not disinfected after discharge: likelihood medium / impact high / level high. Mitigation: fog and ozone-treat beds and rooms after discharge. Owner: infection control

Ways to Prepare Community Hospitals for Rainy-Season Flu

1. Run vaccine drives before the rains
2. Plan beds and antivirals ahead
3. Set up fever screening
4. Create cohort zones on wards
5. Check ventilation in damp buildings
6. Clean nebuliser rooms after every patient
7. Fog and ozone-treat rooms after discharge

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: When is flu season in Bangladesh? A: April to September, peaking in June and July, per 20 years of data.

Q: What share of respiratory patients had flu? A: 22,284 of 172,792, or about 13%.

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 public hospitals 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

Real data from Bangladesh shows that in the tropics flu comes with the rain. Community hospitals that prepare before the season serve their communities best. Reduce the risk with the World Health Disinfection disinfection service for outpatient rooms, wards and corridors, and the ozone treatment service for wards and patient rooms after discharge. To book, call 065-556-6294 or LINE @whd268.

Call 065-556-6294 | LINE: @whd268