The Muak Lek Flood of 25 September 2026: What the Report Says

All place facts in this article come from one Matichon report dated 25 September 2026. Conditions may have changed since, so follow announcements from Muak Lek district and Saraburi province.

• On 25 September 2026 there was continuous heavy rain and water levels rose.
• The area named is villages 12 and 13 of Ban Tha Sao, Muak Lek subdistrict, Muak Lek district, Saraburi.
• The DDPM sent a Cell Broadcast alert telling residents to evacuate.
• The named shelter is Ban Khao Mai Kwian School.

The report gives no water depth, household count, number of evacuees or length of stay, so we include none. The story below is an illustrative example of common evacuation situations, not about real residents and not a description of this particular shelter.

Flooded Areas in Muak Lek: Ban Tha Sao Villages 12 and 13

• Village 12, Ban Tha Sao, Muak Lek subdistrict: alerted to evacuate.
• Village 13, Ban Tha Sao, Muak Lek subdistrict: alerted to evacuate.
• Ban Khao Mai Kwian School: the shelter named in the DDPM alert.

A Cell Broadcast goes straight to every mobile phone in the area, so many families had to decide to leave quickly. Some may not have packed everything, food was left in fridges, and doors and windows were shut tight. When the water drops, a house closed up through days of very humid weather becomes ideal for mould and bacteria. For village-level detail, check with the village head, the local administration or the Muak Lek district office.

Example Case: Three Nights in a Classroom Turned Bedroom, Then Home to a Musty Smell

A typical scenario (illustrative, not a real person)

That night Fon's phone buzzed with an alarm she had never heard before. The message said to evacuate to the school shelter. Her mother grabbed Grandma's blood pressure pills, a few clothes and important papers, while her father lifted the TV onto a table, locked the door and drove everyone out.

In this imagined shelter, one classroom held several families sleeping side by side on mats and sharing the pupils' toilets. On day two the child on the next mat began coughing with a fever. On day three a few adults had diarrhoea, and Grandma complained of sore, red eyes.

When they were told they could go home, they found the water had reached the floor and left a layer of mud. The sealed rooms smelled strongly musty, black spots had appeared low on the walls, and food in the fridge had spoiled during the power cut. Where should they start, and how would they know the house was ready for Grandma to sleep in again? As for her red eyes, the answer is simple: take her to a doctor. The rest is why we wrote this ranking.

How WHD Built This Post-Flood Germ Ranking for Muak Lek

This is an editorial ranking by WHD, not an official one, and it is not based on case data from the shelter or the district, which we do not have. Unlike other articles in this series, it gives extra weight to evacuation and crowding. Our criteria:

1. Relevance to floods and evacuation in WHO, CDC and Thai Department of Disease Control guidance, including warnings about infections in shelters.
2. Fit with the local situation: continuous heavy rain, rising water, urgent evacuation and homes left shut.
3. Severity based on general medical knowledge.
4. Risk groups: older people, young children, pregnant women and people with chronic illness staying in crowded rooms.
5. Persistence on surfaces, described qualitatively only.
6. Ease of spread where many people share toilets, dishes and air.

A lower rank is not a safety rating. Protect against all ten, and see a doctor for any symptoms.

Post-Flood Germ Ranking Muak Lek 2026: The Top 10 in the Shelter and Back Home

Ranks 1 to 5 focus on crowding and the move home; ranks 6 to 10 focus on what waits inside houses that were shut while the water rose.

1. Norovirus, the Fastest-Spreading Stomach Bug in Group Shelters

Why first: Norovirus is a leading cause of vomiting and diarrhoea outbreaks wherever people live together, from shelters and schools to cruise ships. A tiny dose can infect, it lingers on surfaces, and shared toilets with limited handwashing water let it move fast.

Where it hides: toilets, taps, door handles, shared eating tables, food-serving utensils, and mats or blankets soiled by vomit.

Symptoms and risk: sudden vomiting, watery diarrhoea and cramps. Children and older adults dehydrate quickly; little urine, drowsiness or inability to keep fluids down needs a doctor.

Prevention and disinfection: wash with soap and water before eating and after the toilet, keep sick people out of food preparation, and clean vomit at once with gloves. Norovirus is listed in the CHEMGENE HLD4H product information, so once the shelter closes, cleaning and then spraying toilets, classrooms and the canteen is a fitting step before school resumes.

2. Respiratory Viruses: Influenza, RSV and COVID-19

Why second: Sleeping in rows in classrooms, damp air and exhaustion help respiratory viruses spread. WHO notes that crowding after disasters raises respiratory infection risk, and infants and elders can become seriously ill.

Prevention and disinfection: masks when symptomatic, space between mats where possible, open windows and separate cups. The service information lists COVID-19, RSV, H1N1 and H5N1, so spraying classrooms used as bedrooms after cleaning reduces them on surfaces before pupils return, though it cannot stop person-to-person spread directly. Laboured breathing needs urgent care.

3. E. coli (Escherichia coli) and Sewage Bacteria in Homes the Water Reached

Why third: The first thing families meet at home is mud. CDC says floodwater should always be treated as contaminated with sewage, and E. coli is its clearest marker. Everyone who starts cleaning faces this risk straight away.

Where it hides: floors, bathrooms, backflowing drains, kitchens, submerged dishes, flooded fridges, rugs and mats.

Prevention and disinfection: wear gloves and boots, discard food touched by floodwater or spoiled by power cuts, wash hands before eating and keep children out until cleaning is done. Shovel and wash first, then spray. E. coli is in the general bacteria group the product covers, with no specific test shown online; ask WHD for data.

4. Leptospira (Leptospirosis) While Wading Home and Cleaning Up

Why fourth: The trip home is when many people wade without protection, eager to see the damage, and rats escaping the water often move into closed houses. The Department of Disease Control warns about leptospirosis after every flood.

Symptoms and risk: sudden high fever, headache, severe calf pain and red eyes; people with foot wounds are most at risk. Fever in the days to few weeks after wading means seeing a doctor and mentioning it.

Prevention and disinfection: boots, waterproof plasters and gloves when handling items with rat droppings. Leptospira is in the general bacteria group without a specific test shown online. Spraying the house after washing reduces surface risk, but it never replaces protection while wading.

5. Hand, Foot and Mouth Disease Viruses in a School Used as a Shelter

Why fifth: When the shelter is a school, many children share the space during the evacuation and again when lessons resume. The disease is common in the rainy season and spreads through saliva, mucus, blister fluid and stool, with toys and desks as key carriers.

Symptoms and risk: fever, mouth sores and spots on hands, feet and buttocks. Drowsiness, frequent vomiting or jerking movements need urgent care.

Prevention and disinfection: frequent handwashing, separate personal items and sick children kept home as a doctor advises. The service information lists hand-foot-mouth virus and names schools among its customers, so spraying classrooms, toilets and the canteen after the shelter closes and cleaning is complete is a sensible step before reopening.

6. Adenovirus, a Common Cause of Pink Eye After Floods

Why sixth: Conjunctivitis is one of the illnesses Thailand's Department of Disease Control often warns about during floods. It spreads through hands, shared towels and dirty water, and moves quickly in crowded places. Adenovirus is a frequent cause of viral pink eye.

Prevention and disinfection: do not rub eyes, do not share towels, handkerchiefs or eye drops, wash hands and never wash your face with floodwater. See a doctor for severe pain or blurred vision. Adenovirus is not on WHD's listed organisms, so we place it in the general virus group only.

7. Mould in Homes Shut During the Evacuation: Cladosporium, Aspergillus and Stachybotrys

Why seventh: A sealed house with water inside during heavy rain traps humidity with no airflow. CDC and WHO advise drying within about 24 to 48 hours to limit mould, but while owners are at the shelter that window usually passes.

Prevention and disinfection: air the house before working inside for long, wear a mask and gloves, discard porous items with heavy growth and dry the structure before repairs. Scrub and dry first, then spray; the service information covers fungi and mould in general, without species-specific tests. For persistent mustiness, consider residential ozone disinfection.

8. Wound Bacteria from Clean-Up: Staphylococcus aureus and Tetanus Risk

Why eighth: Clean-up uncovers glass, nails and sharp debris in the mud. Wounds contaminated with soil and floodwater infect easily, and deep dirty wounds carry a tetanus (Clostridium tetani) risk, so ask a doctor about vaccination.

Prevention and disinfection: closed shoes and thick gloves, rinse and cover wounds, and see a doctor for deep or inflamed wounds. Spraying does not treat wounds or prevent tetanus; it reduces bacteria on shared surfaces. Staphylococcus sits in the general bacteria group.

9. Hepatitis A Virus from Contaminated Food and Water

Why ninth: Hepatitis A spreads faecal-orally, through relief food or contaminated household water, and its long incubation means symptoms may appear weeks after people return home.

Prevention and disinfection: freshly cooked food, safe water and cleaned water tanks; see a doctor for yellow skin or eyes and ask about vaccination. Hepatitis A is not on WHD's list, so it sits in the general virus group only.

10. Skin Fungi: Dermatophytes and Candida from Wet Shoes and Feet

Why tenth: During evacuation many people have only one pair of wet shoes, then spend days in mud cleaning up. Damp feet develop immersion foot and fungal infection easily. Mild, but very common.

Prevention and disinfection: dry feet and toe gaps, change socks, dry shoes and never share them. Wash and spray bathroom floors and shoe areas in homes and the school; these fungi fall in the general fungi group.

What the Flood Costs Ban Tha Sao Families and the Shelter School

Health: an urgent evacuation drains body and mind, crowding raises infection risk, and then families face mud and mould at home, so the risk runs for weeks. Money and time: spoiled fridge food, flood-hit appliances, mouldy mattresses and days off work to clean. The school: a school that served as a shelter must be restored for pupils. Classrooms used as bedrooms, toilets used by many people and a canteen used for relief cooking all need systematic cleaning, and parents want confidence before sending children back. Peace of mind: worry about the water returning, and about when elders can sleep at home again, is real. A clear sequence of steps reduces confusion.

Why Ordinary Cleaners Alone May Fall Short, for Homes and Schools

• Many shared areas: multiple classrooms, toilets and a canteen hold countless touch points; wiping one by one takes long and misses spots.
• Home-mixed bleach may be the wrong strength or irritating, and must never be mixed with ammonia or some toilet cleaners.
• Short contact time when surfaces are wiped and rinsed immediately.
• Trapped humidity in shut homes lets mould return without thorough drying and treatment.
• Limited staff: a few teachers and caretakers face a whole school.

CDC advises cleaning before disinfecting. Spraying by trained technicians is the follow-up that reaches surfaces more evenly.

WHD Post-Flood Disinfection Spraying for Muak Lek

World Health Disinfection is based in Bang Khae, Bangkok 10160, with no branch in Saraburi. Jobs in Muak Lek and nearby areas are arranged via 065-556-6294 or LINE @whd268, depending on schedule and roads. We do not promise same-day arrival.

According to the disinfection spraying service page:

• Trained technicians spray and/or ULV-fog (Ultra Low Volume fine mist).
• The disinfectant is CHEMGENE HLD4H, a medical-grade UK product containing Benzalkonium Chloride and Didecyldimethylammonium Chloride.
• Listed organisms include COVID-19, RSV, H1N1, H5N1, hand-foot-mouth virus, bacteria and fungi, with a claimed 99.99% and broad-spectrum coverage.
• The page cites the Department of Medical Sciences, Mahidol University, NHS England and EN 14476:2013+A2:2019.
• Customers include hospitals, schools, malls, airports, offices, airlines, banks and residential buildings.
• A free CHEMGENE spray bottle and WELLGIENIC wet wipes come with the service, and tax invoices are available.

Spraying happens only after mud removal and washing; it does not replace cleaning, drying or medical care. People, pupils and pets leave the zone during application and return at the technicians' stated time, about 30 minutes in general per the page. We do not claim zero residue.

Process for Homes After Evacuation and Schools After a Shelter Closes

1. Send photos and details via LINE @whd268, such as the number of classrooms and toilets or the size of the house.
2. Air the building before working inside for long.
3. Remove mud and damaged items, including spoiled food and heavily mouldy materials.
4. Wash surfaces, mats, desks and toilets with clean water and detergent.
5. Zone the site: classrooms, toilets, canteen, or rooms of the house.
6. Spray with everyone out of the zone.
7. Re-enter at the stated time and ventilate.
8. Monitor illness among pupils and family members, and damp in the building.

10 Reasons Muak Lek Homes and Schools Should Disinfect After the Water Drops

1. Shelters house many people, and stomach and respiratory germs can remain on surfaces.
2. Schools need to welcome pupils back quickly.
3. Parents want to know classrooms were cleaned systematically.
4. ULV fogging covers large areas more evenly than spot wiping.
5. Hand-foot-mouth virus, norovirus and influenza are on the product's listed organisms.
6. Homes left shut hold humidity and need surface treatment after washing.
7. Elders can return room by room in a clear order.
8. It lightens the load on teachers and caretakers.
9. A clear process from survey to re-entry. See details.
10. Tax invoices for schools, local agencies and shops.

Before and After Spraying

Checklist for Ban Tha Sao Residents and the Shelter School

While in the shelter: wash hands with soap before eating and after the toilet; wear a mask and tell staff if you have a fever or cough; do not share towels, handkerchiefs or cups; bring elders' regular medicines.

Before spraying a home or school: air the building first; wear boots, gloves and a mask; discard spoiled or flood-touched food; remove mud and wash surfaces with clean water and detergent; move food, dishes and personal items out of the zone.

After spraying: re-enter at the stated time and open windows; rewash food containers; watch for new mould in the following weeks; see a doctor for fever, calf pain, diarrhoea, red eyes or infected wounds.

FAQ: Post-Flood Germ Ranking for Muak Lek

How deep was the water in Ban Tha Sao?

The Matichon report of 25 September 2026 gives no depth. It says there was continuous heavy rain, water rose, and the DDPM sent a Cell Broadcast to evacuate to the Ban Khao Mai Kwian School shelter.

Is this ranking based on shelter case data?

No. It is WHD's editorial ranking using the criteria above, and the story is an illustrative example, not an account of this shelter.

When should a school be sprayed?

After the shelter closes, all occupants have left, and classrooms, toilets and the canteen have been cleaned, before lessons resume. Pupils and staff stay out of the zone during spraying.

Does the disinfectant work on pink eye?

Adenovirus is not on WHD's listed organisms, so it sits in the general virus group. Ask the team for test data, and anyone with red eyes should see a doctor.

Does WHD have a branch in Saraburi?

No. WHD is in Bang Khae, Bangkok 10160. Upcountry jobs are arranged via 065-556-6294 or LINE @whd268.

Talk to Us About Post-Flood Disinfection in Muak Lek

Send photos of your home, classrooms or toilets and our team will help plan the right order of work for families and schools alike.

See the Disinfection Spraying Service

Call 065-556-6294 | LINE @whd268

Related Services

• WHD Disinfection Spraying Service
• CHEMGENE HLD4H Disinfectant
• Residential Ozone Disinfection

References

• Matichon: heavy rain and evacuation alert, Ban Tha Sao, Muak Lek, 25 Sep 2026 matichon.co.th/region/news_5905051
• CDC: Floods cdc.gov/floods
• WHO: Fact sheets who.int/news-room/fact-sheets
• Department of Disease Control, Thailand ddc.moph.go.th