Flu and RSV in Damp Homes During the Rainy Season and After Floods: How to Stop the Whole Family Getting Sick in Turn, and Reset Rooms with Ozone Once Everyone Recovers

The Thai rainy season brings more than rising water. It is also the time of year when influenza and RSV, the respiratory virus that can leave babies struggling to breathe, tend to rise noticeably. When a flood crowds relatives into one closed, humid house, illness can pass from one person to the next. This guide explains why, who is most at risk, which warning signs need a doctor now, and the correct role of ozone disinfection: a room reset after the sick have recovered and the house has been cleaned and dried, never a replacement for vaccination, handwashing or medical care.

A Typical Scenario: A Two-Storey House in Pathum Thani Where Everyone Got Sick Within Three Weeks

After water from the Rangsit canal spilled into a housing estate in Pathum Thani and left ground floors knee-deep, Nid's family moved everything upstairs. It was not just her own household. Her parents, both in their seventies, came too, because their single-storey house had flooded up to the window sills. So did her younger sister, who had given birth four months earlier. Seven people now shared two bedrooms and a narrow landing, mattresses laid edge to edge. The windows stayed closed because the rain never stopped and the smell of sewage drifted up from below. The air conditioner ran day and night so that anyone could sleep.

In the first week, Nid's nine-year-old nephew came home from school with a high fever, aching muscles and a dry cough. Two days later her father had a fever, then her mother, then Nid's own throat hurt. Most frightening was the four-month-old baby: a runny nose turned into fast breathing, poor feeding and a whistle with every breath. The family rushed her to hospital at night. The doctor diagnosed RSV and admitted her for observation, while the adults were diagnosed with influenza.

Even as everyone recovered and the water fell, the shared upstairs bedroom smelled musty, the curtains and mattresses held the odour, and dark spots appeared in the wall corners. Nid worried that bringing the baby back into that room might irritate her airways again. Many Thai families face this question every flood season, and it takes several steps together, not one quick fix.

Note: this is an illustrative scenario based on problems commonly seen in flooded areas. It is not a review or the record of any specific customer.

Understanding Flu and RSV: Two Respiratory Viruses That Thrive in the Rainy Season

What is influenza?

Influenza is caused by influenza viruses. Unlike a common cold, it usually comes on suddenly and hits harder. People often develop a high fever all at once, a headache, aching muscles throughout the body, deep fatigue, a dry cough, a sore throat and a runny nose. Most healthy adults recover within about a week, but in older people, young children, pregnant women and anyone with a chronic illness, flu can lead to pneumonia or breathing failure, or make an existing condition worse. That is why Thailand's Department of Disease Control recommends that at-risk groups get a flu vaccine every year, ideally before the rainy season begins.

What is RSV?

RSV, or respiratory syncytial virus, infects people of all ages. In most adults it looks like a normal cold. In babies and young children, especially those under two, those born prematurely and those with heart or lung conditions, the virus can reach the small airways and the lungs, causing bronchiolitis or pneumonia. The child breathes fast and hard, wheezes, the skin between the ribs pulls in with each breath, and they feed or drink less. Older adults and people with chronic lung disease are also at risk of severe illness. In Thailand, RSV tends to be most common during the rainy season, which overlaps exactly with the months when many areas flood.

How these viruses spread inside a home

Both flu and RSV spread through droplets from coughing, sneezing or talking at close range, and through touching contaminated surfaces and then touching the eyes, nose or mouth. The viruses can survive for hours on hard surfaces such as door handles, TV remotes, bed frames, stair rails, mobile phones and children's toys. In a house where people are crowded together, share belongings and keep every door and window closed, the chances of the virus moving from one person to another multiply.

Why illness passes around more easily after a flood

A flood does not create flu or RSV, but it helps viruses already in the community spread. People crowd into whatever dry space is left, so the distance between them shrinks. Doors and windows stay closed, so indoor air barely changes. Humidity rises and mold grows on walls, carpets and furniture; spores and musty odours irritate the airways, trigger allergy and asthma flare-ups, and can make a cough drag on. And stress, poor sleep and exhausting work wear down everyone's resistance. Together, these can keep one household cycling through illness for weeks.

Who is most at risk

• Babies and children under two, particularly premature babies, who are at risk of severe RSV.
• Older adults, whose immunity weakens with age and who are more prone to pneumonia as a complication.
• Pregnant women, who face a higher chance of complications from flu than the general population.
• People with chronic illness, such as heart disease, lung disease, asthma, diabetes and kidney disease, and anyone with weakened immunity.
• People with allergies or sensitivity to mold, whose respiratory symptoms can overlap with and be worsened by infection.

When the Whole House Keeps Getting Sick: The Impact Goes Beyond Fever and Coughs

Health

When illness passes along a chain, the household never truly recovers, and the caregiver ends up exhausted and sick too. An older parent just over flu, sleeping in a damp room full of spores, may keep coughing for weeks. A child who has had RSV may have sensitive airways for a while afterwards, so returning to a musty, spore-laden bedroom is the opposite of what they need.

Money

Medical bills and a baby's hospital stay pile on top of house repairs, new furniture and income lost while caring for the sick.

Time and work

Parents take turns on leave, children miss school, small businesses cannot reopen properly, and the house restoration stalls. Everything slows down at once.

Emotional strain on the family

Losing belongings while worrying about a newborn and elderly parents leaves families drained. Nobody is sure which room is safe enough for the baby, and that uncertainty is why families want a clear, step-by-step way to trust their home again.

Why the Usual Fixes Do Not Break the Cycle

• Running the air conditioner in a sealed room all day: it keeps everyone cool, but with no fresh air the same droplet-laden air circulates in one room. If the filter or cooling coil has become damp and moldy, it also blows musty air straight back in.
• Wiping only the surfaces you can see: wiping tables and floors is good, but viruses often sit where people forget: light switches, door handles, remotes, bed frames, stair rails, curtains and fabrics that are never fully wiped.
• Air freshener or incense to cover the smell: fragrance does nothing to reduce germs, and some scented products irritate the airways of babies and people with asthma.
• Strong bleach sprayed throughout the room: over-concentrated solutions give off fumes that sting the nose, especially in a closed room with a young child, and they cannot reach into fabrics or tiny gaps.
• Painting over dark patches: fresh paint makes a wall look clean, but if the wall is still damp inside, mold returns within weeks and keeps releasing spores.
• Relying on fans alone: fans do speed up drying, but they also stir up dust and spores across the room if the source has not been cleaned first.
• Bringing the baby straight back to the same room after hospital: while the sheets, pillows and curtains are still unwashed and the room still smells damp.

These methods treat only part of the space or hide the visible symptom. Effective recovery follows an order: care for the sick until well, clean and dry the house, wash every fabric, and only then disinfect the whole room.

Ozone Disinfection by World Health Disinfection: A Room Reset After Recovery

Ozone (O3) is a form of oxygen made of three atoms with strong oxidising power. Released at a controlled concentration inside a sealed room, the gas spreads through the entire air volume and into corners, curtains, mattresses, sofas and surfaces a hand cannot reach. Ozone breaks down the structures of viruses, bacteria and mold, and breaks apart odour molecules, then reverts to oxygen (O2) without leaving chemical residue. That matters a great deal in a room where a baby or someone with a respiratory condition is about to live again.

The residential and building ozone disinfection service from World Health Disinfection has been tested and certified by Thailand's Department of Medical Sciences and by Intertek (UK), eliminating viruses, bacteria and mold by 99.99% according to the test results the company holds. You can view the certification documents on the website.

When ozone treatment makes sense

• After everyone with flu or RSV in the house has recovered, and before a young child or older person moves back into their bedroom.
• After relatives who stayed during the flood have gone home and you want the rooms ready for normal use.
• After a flooded ground floor has been cleaned and dried but a damp smell lingers.
• Before moving into or renting out a room that went through a flood and housed sick people.

How the process works

1. Survey and assessment: the team asks about recent illness in the household, checks moisture, mold spots and odours, and plans zones such as bedrooms, living areas and shared rooms.
2. Preparation: people, pets, plants and fresh food are removed, windows are closed, the air conditioner is handled as advised, and cupboards and drawers are opened so the gas can reach inside.
3. Ozone release: a professional ozone generator fills the space at a concentration matched to the room size. A typical cycle is about 30 minutes per zone.
4. Contact time: the room stays sealed so ozone can react with germs and odour molecules.
5. Rest and ventilation: the ozone is allowed to revert to oxygen, the room is aired, and people return only at the time the team gives.
6. Handover and advice: the team explains how to manage humidity and ventilation so mold does not come back.

For ozone jobs of 15,000 baht or more, you receive a free medical-grade disinfectant spray for wiping frequently touched points day to day. For general cleaning options, see our ozone cleaning service.

10 Reasons Families with Babies and Elders Choose Ozone After a Season of Illness and Flooding

1. It reaches what wiping misses. Ozone gas gets to bed frames, the backs of wardrobes, under sofas and into fabric, the places hand-cleaning often overlooks.
2. Air and surfaces in a single cycle. Instead of wiping item by item, professional ozone treatment covers the full volume of the room.
3. It removes the musty smell that irritates the nose. Odours in curtains, rugs and mattresses are broken down at the molecular level, not masked.
4. No chemical residue. Ozone returns to oxygen, which suits a nursery where a baby crawls, chews and puts everything in their mouth.
5. It helps tackle the mold that worsens coughs. Done after visible mold is removed and walls are dry, it helps reduce spores that keep allergic children and asthmatic adults coughing.
6. Independently tested. Certified by the Department of Medical Sciences and Intertek, according to the test results the company holds.
7. Fast turnaround. About 30 minutes per zone, so families are usually back home the same day once the rest and ventilation period is over.
8. Ideal after hosting relatives. It helps restore bedrooms that many people have shared before the usual occupants move back.
9. Peace of mind before a baby comes home from hospital. Parents know the room has been cleaned and disinfected through every step. See the service details.
10. Handled safely by professionals. The team controls concentration, timing and ventilation, so you do not have to take chances with a machine you do not know. Book a site survey.

Before and After Ozone: From a Room Where Everyone Got Sick to a Room Ready for the Smallest Family Member

Example Case: Praew in Nonthaburi and a Bedroom That Had to Be Ready Before Her Son Left Hospital

Praew lives in a townhouse in Bang Bua Thong, Nonthaburi. During the flood, the road in front of her house was under water for almost two weeks and about a hand's width of water seeped into the ground floor. Five members of her husband's family, whose home sits lower, moved in. During that time her ten-month-old son caught RSV and was admitted to hospital, while three adults in the house came down with flu one after another.

When the doctor said her son could come home in a few days, Praew worked in order. Recovered relatives went home. She hot-washed and sun-dried sheets, blankets and curtains, threw out the soaked rug, wiped high-touch points, had the air conditioner cleaned, and ventilated until the ground-floor walls were dry. Only then did she contact World Health Disinfection to ozone-treat the upstairs bedroom, the living room and the ground floor, on a day when the whole family went to stay at her mother's house.

The team divided the house into three zones, ran about 30 minutes per zone, then sealed the rooms to rest and ventilated them before handover. When Praew came back that evening she noticed that the musty smell trapped in the bedroom was clearly gone. What she valued most, she explained, was not just a clean room but the reassurance that every step had been done before she carried her son back in. She still took him to his follow-up appointments with the doctor, and everyone in the house washed their hands before picking him up.

This example case is an illustrative scenario written to explain the process. It is not an identifiable customer review. Results in each home depend on the space, humidity levels and preparation before treatment.

Checklist: Breaking the Flu and RSV Cycle at Home After a Flood

While someone in the house is sick

• Get high-risk patients to a doctor early, especially babies, older adults, pregnant women and people with chronic illness.
• Keep the sick person in a separate room or corner where possible, and ask them to wear a mask around others.
• Wash hands with soap often, especially before holding a baby, before preparing food and after wiping a runny nose.
• Do not share glasses, spoons, handkerchiefs or towels.
• Wipe high-touch points several times a day: handles, switches, remotes, phones and stair rails.
• Open windows for fresh air whenever the rain stops, even if the air conditioner is on.
• Any adult who waded through floodwater and then gets a fever should tell the doctor about the flood exposure.

Before ozone treatment (after everyone has recovered)

• Finish mud removal and cleaning of flooded areas, and dry the house as fast as possible, following the general WHO and CDC advice to clean and dry within 24 to 48 hours to limit mold.
• Throw away absorbent materials that soaked up floodwater and started to grow mold, such as carpets, foam and waterlogged mattresses.
• Wash sheets, pillowcases, blankets, curtains and children's soft toys, and dry them completely.
• Clean the air conditioner and wash or replace its filters.
• Pack food, medicines, baby bottles and baby equipment into closed boxes or take them out of the room.
• Schedule a day when people, pets and plants can all leave the house.

After ozone treatment

• Return only at the time the team gives, after the rest and ventilation period.
• Control humidity with a dehumidifier or daily ventilation.
• Keep washing hands and wiping high-touch points as a routine, because new germs come in whenever people go out.
• Ask your doctor about flu vaccination for at-risk family members and about RSV protection options for infants.
• Watch for new damp patches or dark spots and fix the source of moisture before they spread.

Frequently Asked Questions

Q: Will ozone treatment stop my child catching flu or RSV?
A: Not directly. These viruses mainly spread from person to person. Ozone helps reduce germs left on surfaces and in room air after the sick have recovered, and removes musty odours that irritate the airways. The main protection is still vaccination as advised by your doctor, handwashing, separating the sick and good ventilation.

Q: Can you treat a room while a sick person is resting in it?
A: Absolutely not. Ozone treatment is only done in an empty room. People, pets and plants must leave, and return only after the rest and ventilation period.

Q: How long should we wait after the illness?
A: We recommend treating after everyone in the house has recovered, and after cleaning, washing fabrics and drying. That way one reset does the job. If someone is still sick, new virus will come straight back into the room.

Q: Will there be any residue in the nursery?
A: Ozone reverts to oxygen after the rest period, so it leaves no chemical residue on surfaces, unlike spraying strong chemicals everywhere. Still, air the room as advised before bringing the baby in.

Q: How long does it take?
A: Typically about 30 minutes per zone, not counting preparation and the rest and ventilation period. Most homes are finished in a day.

Q: My child still coughs after RSV. What should I do?
A: See a doctor for an assessment, as there may be airway sensitivity or another issue. Reducing damp and mold in the bedroom supports recovery as an environmental measure, but it is not treatment.

Q: Can I use a home ozone machine instead?
A: Small units may not be powerful enough for a whole room, and using one without controlling time and ventilation can harm the airways. For equipment information see our ozone disinfection machines page, or choose a professional team.

Give Your Family Back a Fresh, Comfortable Home

Once the fevers have broken and the water has gone, do not leave the bedrooms full of damp smells and reminders of the weeks everyone was ill. Let the World Health Disinfection team reset your home as the final step before your little one and your older relatives move back in.

Book an Ozone Room Reset

Call 065-556-6294 · LINE @whd268 · Email worldhealthdisinfection@gmail.com

Related Services

• Residential and building ozone disinfection
• Ozone cleaning service
• Certificates and test results
• Contact World Health Disinfection

References

• Department of Disease Control, Thailand
• World Health Organization fact sheets