Melioidosis After a Flood: When Mud Flows Into Homes in Northeast Thailand, and How Ozone Helps Finish a Safe Recovery

When people think of diseases after a flood, they usually think of leptospirosis, diarrhoea and mold. In Northeast Thailand, however, there is another illness that local doctors watch for every rainy season: melioidosis, caused by a bacterium that lives in soil and surface water. When floodwater pushes mud into a home and leaves it layered across floors, kitchens and wall cavities, a germ that normally stays out in the rice fields suddenly sits right next to the family. This article explains what the bacterium is, who is most at risk, how to clear mud safely, and where ozone disinfection fits in as the finishing step after cleaning.

A Typical Scenario: A House by the Mun River in Ubon Ratchathani

Uncle Sommai is sixty-two and lives in a raised, half-wood, half-concrete house in Warin Chamrap district, Ubon Ratchathani, close to the Mun River. He has had diabetes for years and takes medicine and insulin every day to control his blood sugar. This year the Mun overflowed and flooded the ground floor of his house for almost three weeks. When the water finally drained away, it left a layer of grey-brown mud nearly a hand-span deep across the entire floor, and a smell of wet earth and rot that filled the house.

He did not want to wait for his children, who work in Bangkok, so he started shovelling at dawn. His rubber boots had been washed away, so he worked barefoot, scooping mud out of the kitchen corners with his bare hands. He had a small cut on his foot from a broken tile but paid no attention to it. Two days later the remaining mud had begun to dry, and he swept it with a stiff coconut-rib broom, raising clouds of fine dust that he breathed all day.

About two weeks after that, he developed a fever that came and went, a cough, breathlessness, and the cut on his foot became red and swollen instead of healing. His daughter took him to hospital. The doctor asked specifically about contact with flood mud and admitted him for thorough investigation. His daughter said later that she had never imagined the mud in her father's house could be linked to an illness serious enough to need a hospital bed.

This is an illustrative scenario. It does not mean that everyone who shovels mud will fall ill. It shows how small habits, such as going barefoot, leaving a cut uncovered and sweeping dry mud, can quietly raise the risk, especially for someone with diabetes.

Understanding Melioidosis and Burkholderia pseudomallei

Where the bacterium lives

Melioidosis is caused by a bacterium called Burkholderia pseudomallei, which lives naturally in soil and surface water: rice-paddy soil, still ponds, streams, swamps and wells. Thailand is an area where the disease is regularly found, particularly the Northeast, in provinces such as Ubon Ratchathani, Khon Kaen, Si Sa Ket, Roi Et, Surin, Buri Ram and Udon Thani, and cases rise during the rainy season. Thailand's Department of Disease Control typically issues warnings about it each year as the rains arrive.

How floods raise the risk

Normally, the people exposed are rice farmers and others who work with soil and water every day. During a flood, soil from paddies and riverbanks is carried by the current into homes and settles as thick mud on floors, in bathrooms, under cupboards and inside wall gaps. People who never work with soil suddenly find themselves wading through water, walking through mud and shovelling it by hand. The risk spreads from certain occupations to entire families.

Three routes into the body

• Through the skin: via cuts, grazes or scratches that come into contact with contaminated mud or water. This is a common route.
• By breathing: inhaling contaminated water droplets or dust, for example when blasting mud with a high-pressure hose or sweeping dried mud into the air.
• By swallowing: drinking water that has not been boiled or safely filtered, or eating with hands that still carry soil.

Symptoms to watch for

Melioidosis can look like many other illnesses, which is why it is sometimes called a great mimicker. Some people develop fever with skin abscesses or infected wounds. Others have pneumonia-like symptoms: cough, chest pain and breathlessness. Some develop abscesses in internal organs such as the liver or spleen, and severe cases can lead to bloodstream infection, which can be life-threatening. The incubation period ranges from a few days to several weeks, and in some people the bacterium can stay dormant in the body for a long time before causing illness.

• High or persistent fever that does not improve after contact with floodwater or mud
• Cough, chest pain or shortness of breath
• A wound that becomes red, hot, swollen, full of pus, or fails to heal normally
• Boils or swollen lumps under the skin
• Pain in the upper right abdomen, or abdominal pain with fever
• Severe fatigue, weight loss, drowsiness or confusion

Very important: if you develop a fever after contact with floodwater or mud, see a doctor promptly and always tell them that you recently waded through water or cleared mud. Melioidosis must be diagnosed and treated with appropriate antibiotics by a doctor, and early treatment makes a big difference. Ozone treatment of a home is not a medical treatment and never replaces seeing a doctor. Note also that fever with calf pain after wading may be leptospirosis, which also needs prompt medical care.

Who is most at risk

• People with diabetes, the single most important risk group, especially when blood sugar is poorly controlled
• People with chronic kidney disease or kidney stones
• Regular heavy drinkers and people with chronic liver disease
• People with chronic lung disease or thalassaemia
• Anyone on long-term immunosuppressants or steroids
• Older people with several chronic conditions
• Children and pregnant women in the house during clean-up, who should avoid direct contact with mud

Isan has many people living with diabetes, and many households are made up of older adults while younger family members work in other provinces. Elderly people with chronic illnesses are therefore often the first to start shovelling mud, which is exactly where children and grandchildren should step in and plan the work together.

What Happens When the Risk From Mud Is Overlooked

Health. Melioidosis can require a long course of antibiotics, first in hospital and then continued at home. Patients need regular follow-up and must finish every dose their doctor prescribes to reduce the chance of relapse. For older people with other conditions, a serious illness also disrupts the control of their existing diseases.

Money. Travel to the provincial hospital, lodging for relatives and income lost while family members stop work to care for the patient all add up, at the very moment the household is paying to repair the house, replace appliances and restore damaged fields.

Time. Children working in Bangkok or elsewhere have to take leave and travel home repeatedly. House repairs stall, and the mud that has not yet been removed keeps drying and spreading dust.

Family and community. In a village where every household is clearing mud at the same time, several elderly neighbours falling ill together worries the whole community. Some families stay in shelters longer than necessary because they are not sure their homes are safe.

Business. Shops, restaurants and riverside homestays need to show guests that the premises have been cleaned properly. A haphazard recovery can make customers hesitate to return.

Why Traditional Mud Clean-Up Can Quietly Raise the Risk

Working barefoot and bare-handed. This is the most common habit, because boots are lost or in short supply and people assume washing their hands afterwards is enough. Even a tiny graze gives the bacterium a way in.

Blasting mud with high-pressure water in a closed room. It is fast, but it throws a mist of muddy droplets into the air, and anyone standing nearby without a mask breathes it in. Open the doors and windows, use moderate pressure and always wear a mask.

Letting mud dry, then sweeping. Many households wait for the mud to dry because it seems easier to move. Dry mud turns into fine dust that rises every time someone sweeps or walks past. Dampen it first, then scoop or scrape it out.

Pouring bleach on thick mud. Disinfectants work poorly in the presence of lots of soil and organic matter, so pouring them onto deep mud wastes product for little effect. The correct order is: remove all the mud, wash thoroughly, then disinfect the surfaces.

Washing the floor but forgetting hidden pockets. Mud often remains under kitchen cabinets, behind the fridge, in sliding-door tracks and in drain openings. It dries there and releases dust later.

Using contaminated well or jar water. When the mains supply is off, many homes use well water or rainwater jars that floodwater has entered, to wash dishes or even to drink. That is a swallowing risk.

Masking the smell. A lingering smell of wet earth and rot is a sign that moisture and organic matter remain. Perfume or incense does not solve the problem and can hide spots that still need cleaning.

Clearing Mud Safely: The Steps to Finish Before Calling an Ozone Team

1. Dress for protection. Rubber boots above the ankle, thick rubber gloves, long sleeves, long trousers and a well-fitting face mask or dust mask.
2. Cover every wound first. Use waterproof plasters or dressings on all cuts and grazes. If you are injured while working, wash the wound immediately with clean water and soap.
3. Match people to tasks. People with diabetes or kidney disease, elderly people with chronic illnesses, children and pregnant women should avoid direct contact with mud and help with lighter jobs away from it.
4. Remove mud while it is still damp. Scoop and scrape while it is wet, or mist it with water first, to keep dust down.
5. Wash from top to bottom. Clean walls from the top down, then the floor, using clean water and detergent, scrubbing grout lines and skirting.
6. Disinfect only after surfaces are clean. Use a suitable disinfectant according to its label on surfaces from which all mud has been removed. Medical-grade products such as Chemgene are an option.
7. Discard absorbent items. Mattresses, pillows, cushions, carpets and swollen particle-board furniture should leave the house.
8. Dry the house. Open doors and windows and use exhaust fans and dehumidifiers. The WHO and CDC advise cleaning and drying within 24 to 48 hours to limit mold.
9. Look after yourself after work. Shower with soap, change clothes, wash work clothes separately, drink boiled or bottled water, and watch for fever for several weeks.

Where Ozone Disinfection by World Health Disinfection Fits In

Let us be direct: germs carried in mud are dealt with first and foremost by removing the mud and washing. Nothing makes mud removal unnecessary. Ozone comes afterwards as a finishing step that handles what washing cannot reach: the indoor air, crevices that still hold traces of residue, and the smell of rotting earth absorbed into building materials.

Ozone (O3) is a strong oxidiser. When it spreads through an enclosed space it breaks down the cell structures of bacteria, viruses and mold and breaks apart odour molecules, then reverts to oxygen (O2) with no chemical residue. According to test results certified for the company by Thailand's Department of Medical Sciences and Intertek (UK), our system eliminates viruses, bacteria and mold by 99.99%. Those tests were carried out on general microorganisms under controlled conditions, so we recommend seeing ozone as an extra layer of protection, not a guarantee that no particular germ remains. Learn more on our Residential and Building Ozone Disinfection page.

Our process

1. Survey the house. We check the flood level, where mud settled, the kitchen, bathrooms and commonly overlooked gaps.
2. Confirm readiness. Mud must be fully removed and surfaces washed and dry. If mud remains, we point out the spots that still need attention first.
3. Prepare the space. Everyone, including pets, leaves the area and plants are removed. Doors and windows are closed, food and medicines are taken out, and cupboards and drawers are opened so the gas can reach inside.
4. Fill with ozone. The generator runs until the target concentration is reached and the gas penetrates under cabinets, behind the fridge and into gaps no cloth can reach.
5. Contact time. The concentration is held for the required period, typically about 30 minutes per zone.
6. Rest and ventilate. The ozone is left to revert to oxygen, then doors and windows are opened. No one enters until our team confirms it is safe.
7. Handover and advice. We summarise the work and advise on humidity control and on watching for symptoms among household members.

Safety rule: ozone treatment is carried out only in an empty, closed space. No people, pets or plants may be inside, and re-entry is allowed only after the rest and ventilation period set by our team.

10 Reasons to Finish a Post-Mud Recovery With Ozone

1. Treats indoor air after clean-up. Shovelling and washing throw up droplets and dust; ozone helps deal with microbes still suspended indoors. See service details
2. Reaches where mud hides. Under kitchen units, behind the fridge, in door tracks and beneath stairs.
3. Breaks down the rotten-earth smell. The odour that washing cannot lift out of wood and plaster.
4. Leaves no chemical residue. Suitable for kitchens, bedrooms and homes with elderly people or children.
5. Helps limit the mold that follows mud. Moisture trapped in walls breeds mold; ozone adds a layer of protection after drying.
6. Backed by test results. According to test results certified for the company by the Department of Medical Sciences and Intertek, 99.99% elimination. View certificates
7. Spares vulnerable relatives. Elderly people or those with diabetes do not need to scrub hard-to-reach spots again and again.
8. Fast. About 30 minutes per zone plus rest and ventilation time.
9. Suits homes, shops, homestays and buildings. Our team works in homes, condos, hotels, offices, factories, schools and hospitals.
10. Families return with confidence. A clear, explainable process reassures relatives who live far away. Request a quote

Before and After: A Home Fully Cleared and Restored

Note: results depend on complete mud removal, washing and drying before ozone treatment.

Example Case: A Riverside Homestay in Khon Kaen

This example case reflects a common situation; it is not a review from a specific customer. Kaew runs a small six-room homestay beside a lake in Khon Kaen. When floodwater rose about half a metre, mud settled in the ground-floor rooms and the shared kitchen. Her father, who has diabetes, lives with her, so she decided he would not help with the mud and instead hired villagers who had proper boots and gloves.

The crew removed the mud while it was still damp, washed walls and floors from top to bottom, threw out soaked mattresses and curtains, and ran fans for several days until the floors were dry. The kitchen and rooms still carried a musty, earthy smell, and Kaew worried guests would notice it the moment they opened the door.

Our team surveyed the property, confirmed the mud had been fully removed, and ozone-treated the ground-floor rooms and the kitchen one zone at a time, while the family stayed upstairs in a separate, fully sealed wing. After the rest and ventilation period, Kaew noticed the earthy smell had gone, and she was able to tell guests with existing bookings that the homestay had been restored and ozone-disinfected. She also put up signs reminding guests to wear shoes near the water and to see a doctor if they develop a fever after their stay.

Checklist Before and After Ozone for Homes in Melioidosis Areas

Before ozone day

• Remove all mud, including under cabinets, behind the fridge and in door tracks
• Wash and disinfect surfaces and dry the house
• Discard absorbent items that cannot be cleaned
• Take food, medicines and drinking water out of the area
• Arrange somewhere for everyone and any pets to stay, and move plants out during treatment
• Open cupboards, drawers and internal doors so the gas can reach inside

After ozone

• Re-enter only after our team confirms it is safe
• Keep doors and windows open to continue ventilating
• Use boiled or bottled water until the mains supply is confirmed safe
• Always wear shoes outside where mud remains around the house
• Keep wounds clean and covered with waterproof dressings
• Watch everyone in the household for fever, cough or infected wounds for several weeks, and see a doctor immediately if symptoms appear
• People with diabetes should keep blood sugar well controlled and tell their regular doctor about their flood exposure

Frequently Asked Questions

1. Will ozone treatment prevent melioidosis?

Ozone helps reduce microbes in the air and on surfaces inside an enclosed home, according to the company's certified tests on general microorganisms. But this bacterium lives in the soil and water around the house, so the main protection remains boots and gloves, covering wounds, clearing mud correctly and drinking clean water. Ozone is a supporting step for the indoors.

2. I cleared mud and now have a fever. What should I do?

See a doctor quickly and mention your contact with floodwater or mud, especially if you have diabetes or kidney disease or are elderly. Do not self-medicate or wait for the fever to pass.

3. When should ozone be done?

After the mud has been removed and the house washed and dried. If mud remains, ozone cannot work at its best, so finish the mud removal first.

4. How long do we need to stay out?

A typical cycle is about 30 minutes per zone, plus rest and ventilation. Our team gives you exact timings based on the size of the house and number of zones. Everyone stays out until the team confirms it is safe.

5. Can a raised wooden house be treated?

Yes. Our team surveys the house and plans how to seal it. Homes with many vents or gaps may need temporary sealing or smaller zones so the ozone concentration is sufficient.

6. Do you serve Isan, and are there promotions?

Ask about service areas and request a quotation by phone or LINE. Ozone jobs of 15,000 baht or more receive a free medical-grade disinfectant spray.

Mud Cleared? Let Us Help You Finish the Job

Talk to the World Health Disinfection team to assess your home after the flood and plan a safe ozone disinfection.

Book Post-Flood Ozone Disinfection

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

Promotion: free medical-grade disinfectant spray with ozone jobs of 15,000 baht or more.

Related Services and Reading

• Residential and Building Ozone Disinfection
• Disinfection services
• Chemgene medical-grade disinfectant
• Contact World Health Disinfection

References

• WHO Fact Sheets
• Department of Disease Control, Thailand