The Theod Rachan Road Flood in Si Kan, Don Mueang, September 2026

According to Daily News on 27 September 2026, Theod Rachan Road in Si Kan, Don Mueang, had standing water along its entire length for a second straight day. Residents drove and waded through the water just to go out and buy food. The report explained that water from the area drains into Khu Nai Kim Sai 1 and then on to Khlong Prem Prachakon, but the level in Khlong Prem Prachakon was high, so drainage was slow and some water flowed back into the neighbourhood. Repeated afternoon rain kept the level from falling as residents had hoped.

Nationally, the Government Public Relations Department, citing the Department of Disaster Prevention and Mitigation (DDPM) as of 06:00 on 7 October 2026, reported flooding in 27 provinces plus Bangkok, covering 123 districts and 984 subdistricts, with 1,154,875 households and more than 3.1 million people affected. Figures change daily.

Three details matter for germ risk. First, water flowing back from ditches and canals is not clean rainwater; it has passed through drains that collect household and restaurant wastewater, sometimes with septic overflow. Second, water standing for days lets porous materials such as plywood, gypsum, rugs, cushions and cardboard soak up contaminated water. Third, people wading out for food means skin, feet and small cuts touch the water again and again. This article does not claim any germ was tested or found on Theod Rachan Road; it uses the event as an example of the conditions WHO and the US CDC warn about after floods.

A Typical Scenario: A Curry-and-Rice Shop Where the Water Would Not Go Down

Note: this is an illustrative example based on common situations after prolonged urban flooding, not the account of any real person or shop.

Nid runs a small curry-and-rice shop in a two-storey shophouse in Si Kan. The ground floor is the shopfront and kitchen; upstairs is where she lives with her five-year-old daughter and her mother, who is almost seventy and has diabetes. On the first morning of heavy rain, water began bubbling up from the drain cover outside. Nid assumed it would recede as usual. Instead it held steady all day, and when rain returned in the afternoon it crept over the threshold into the shop.

On day two, water still covered the road. Regulars waded over to buy boxed rice because the nearby convenience store was closed. The water was murky brown, carrying plastic bags, leaves and grey foam, and smelled like a drain.

When it finally drained, it left a thin film of mud on the tiles, a tide mark at shin height, swollen cabinet legs, a fridge drip tray full of black sediment and slime in the kitchen grout. Nid mopped twice, yet the musty, drain-like smell kept returning. Could she safely cook for the neighbourhood again? Was the floor safe for her daughter? And what about her mother, who had waded out to buy medicine with a small cut on her foot?

Germs That Come With Floodwater on Theod Rachan Road, Don Mueang: Ten to Know

Urban flooding like this has its own pattern: still water mixed with drain, ditch and canal water; rats driven up from sewers into buildings; many food shops and stalls; and people wading out every day. The germs to watch therefore include bacteria, viruses, protozoa and fungi. The information below is general guidance based on WHO, CDC and the Thai Department of Disease Control. It is not a diagnosis or treatment advice; anyone who feels unwell should see a doctor.

1. Leptospira spp. (leptospirosis)

How floods spread it: City rats live in drains, under markets and behind restaurants. When drains overflow, rat urine carrying Leptospira spreads through the water, and rats escaping the flood shelter in storerooms and roof spaces.

Where it hides afterwards: puddles on the road, front drains, wet mud in carports and corners with rat droppings.

Symptoms and who is at risk: sudden high fever, headache, muscle pain especially in the calves, red eyes, usually from a few days to about four weeks after exposure. People who wade often, have foot wounds or clean up barefoot are most at risk.

Prevention: rubber boots and gloves, waterproof plasters on cuts, soap washing after contact, and a prompt doctor visit for any fever after wading, mentioning the flood exposure.

2. Aeromonas hydrophila (freshwater wound infections)

How floods spread it: Aeromonas lives naturally in fresh and brackish water such as ditches and canals. Backflow from the canal brings it into direct contact with the skin of people wading.

Where it hides afterwards: uncovered water tanks, backyard puddles, containers left full of water and wet sediment.

Symptoms and who is at risk: wounds that become red, hot, increasingly painful or pus-filled; some people get diarrhoea after swallowing water. People with liver disease, diabetes or weak immunity should be especially careful.

Prevention: avoid wading with open wounds, wash any wound with soap and clean water straight after contact, and see a doctor if redness spreads or fever appears.

3. Shigella spp. (bacillary dysentery)

How floods spread it: Shigella spreads through the faeces of infected people and only a small dose can cause illness. When drain and septic water mixes with floodwater, it reaches frequently touched surfaces.

Where it hides afterwards: door handles, stair rails, taps, kitchen counters, chopping boards and children's toys that were submerged.

Symptoms and who is at risk: frequent loose stools, sometimes with mucus or blood, cramps and fever. Young children and older adults risk dehydration; bloody stools, high fever or inability to drink need medical care.

Prevention: handwashing before cooking and eating, discarding food touched by floodwater, cleaning then disinfecting kitchens and bathrooms, and keeping sick people away from food preparation.

4. Diarrhoea-causing Escherichia coli (ETEC, EPEC)

How floods spread it: E. coli lives in human and animal intestines and is the standard indicator of faecal contamination. When drains back up, sewage carries diarrhoea-causing types into homes and food shops.

Where it hides afterwards: mud films, tile grout, under sinks, fridge drip trays, doormats, curtains and seat cushions.

Symptoms and who is at risk: diarrhoea, cramps, nausea and sometimes low fever; children, older adults and people with chronic illness dehydrate faster.

Prevention: remove all mud, wash with clean water and detergent, discard what cannot be cleaned, drink bottled or boiled water, and use oral rehydration salts for diarrhoea.

5. Norovirus

How floods spread it: norovirus spreads through faeces and vomit, enters sewage easily and survives a long time on surfaces. Shared toilets and shared food during a flood allow quick group outbreaks.

Where it hides afterwards: toilets, taps, flush buttons, handles, remote controls, phones and shared food containers.

Symptoms and who is at risk: sudden vomiting, diarrhoea and cramps; most people recover in a few days, but young children and older adults can become badly dehydrated.

Prevention: wash hands with soap and water, as alcohol gel alone may not be enough; clean up vomit promptly with gloves; disinfect high-touch surfaces. WHD's product information lists norovirus among the organisms CHEMGENE HLD4H covers.

6. Hepatitis A virus

How floods spread it: hepatitis A spreads by the faecal-oral route through contaminated water, ice and food. During floods, ice and uncooked food become riskier.

Where it hides afterwards: ice buckets, freezers, drinking-water containers, raw vegetables washed in unsafe water and food handlers' hands.

Symptoms and who is at risk: tiredness, poor appetite, nausea, upper-right abdominal pain, yellow skin or eyes and dark urine, often several weeks after exposure; adults usually show clearer symptoms than children. A vaccine exists; ask a doctor.

Prevention: boiled or bottled water, ice from trusted sources, cleaning freezers and ice buckets before reuse, and handwashing before preparing food.

7. Staphylococcus aureus (wound infections and boils)

How floods spread it: many people carry it harmlessly on skin and in the nose, but skin softened by long soaking or scraped by glass, metal sheeting and debris lets it enter and cause infection.

Where it hides afterwards: shared towels, damp bedding, handrails, door handles and cleaning tools that were never dried.

Symptoms and who is at risk: red, hot, pus-filled wounds, boils, sometimes fever; people with diabetes, older adults and long-hours clean-up workers should watch wounds closely.

Prevention: wash wounds at once, cover them with clean gauze, avoid sharing towels and see a doctor if a wound spreads. For cuts from sharp objects or soil-contaminated wounds, also see a doctor about tetanus vaccination.

8. Dermatophytes such as Trichophyton (immersion foot and athlete's foot)

How floods spread it: immersion foot starts as skin softened and irritated by long soaking; if skin stays damp, dermatophyte fungi such as Trichophyton move in. Wading daily for several days raises the risk.

Where it hides afterwards: damp shoes, socks, doormats, bathroom floors and shared foot towels.

Symptoms and who is at risk: white, soggy, itchy, stinging or peeling skin between the toes, sometimes with odour; scratching can lead to bacterial infection. People with diabetes should see a doctor early.

Prevention: wash and fully dry feet after wading, especially between toes, change socks often, dry shoes completely and do not share foot towels.

9. Cryptosporidium spp. and Giardia lamblia (protozoa)

How floods spread it: both come from human and animal faeces as tough cysts or oocysts, so sewage backflow can carry them into water supplies.

Where it hides afterwards: storage tanks reached by floodwater, water containers and produce washed in unsafe water.

Symptoms and who is at risk: watery diarrhoea, cramps and bloating lasting days to weeks; people with weak immunity can be seriously ill and should see a doctor.

Prevention: the key step is boiled or bottled drinking water, because Cryptosporidium oocysts resist chlorine and many common disinfectants. Spraying is not the main defence here; removing mud, cleaning water tanks and handwashing reduce exposure most.

10. Aspergillus spp. (mould on damp walls and ceilings)

How floods spread it: mould spores are always in the air. Walls, gypsum, plywood and cardboard that stay wet for days give them a place to grow. CDC advises cleaning and drying within 24 to 48 hours to limit mould.

Where it hides afterwards: inside cabinets, behind wardrobes, under rugs, in leaking ceilings, air-conditioner vents and boxes stored on the floor.

Symptoms and who is at risk: stuffy nose, sneezing, cough, eye and throat irritation; asthma and allergies can flare. People with very weak immunity, such as those on chemotherapy, should avoid mouldy areas and consult a doctor.

Prevention: ventilate, use fans or dehumidifiers, discard mouldy porous items and wear a mask and gloves when cleaning. WHD's product information states it covers fungi in general.

From Knowing the Germs to Reducing Them

All ten share hiding places: mud, tide marks, slime and materials that stay wet. WHO and CDC therefore recommend a sequence: remove mud and debris, wash surfaces with clean water and detergent, dry them, then disinfect surfaces that touched floodwater. Spraying a disinfectant that covers bacteria, viruses and fungi is the final step that reduces germs left after washing.

On efficacy, WHD's product and service information lists organisms CHEMGENE HLD4H covers, including norovirus, Salmonella, mycobacteria, RSV, influenza H1N1 and H5N1, hand-foot-mouth virus, bacteria in general and fungi. For the other germs here, such as Leptospira, Aeromonas, Shigella, E. coli, hepatitis A, Staphylococcus and dermatophytes, this article does not claim an organism-specific test result. They belong to the bacteria, virus or fungi groups the product says it covers, and you can ask WHD for test data on any specific organism.

Why Mopping Alone Is Not Enough After Standing Water in Don Mueang

Mopping, bleach and fans help, but they have limits.

Floor cleaners are made to lift dirt, not to disinfect at post-flood level. Mopping removes mud, yet germs can remain in grout, door edges and rough surfaces.

Home-mixed bleach is often inconsistent. Too strong irritates the lungs; too weak does little. Mixing bleach with some toilet cleaners can release toxic gas.

People clean what they can see. Lower walls up to the tide mark, table legs, the space under counters, behind the fridge, stair rails and high-touch points are often missed.

Air fresheners and fans only mask odour. A lingering drain or musty smell signals moisture and organic residue that feed bacteria and mould.

Cleaning remains essential. Systematic spraying by trained technicians then makes sure every surface that touched floodwater receives disinfectant.

WHD Post-Flood Disinfection Spraying for Homes and Shops on Theod Rachan Road

World Health Disinfection (WHD) provides disinfection spraying for homes, shophouses, shops, offices and buildings. According to the service information, trained technicians spray and/or ULV-fog (Ultra Low Volume fine mist) with CHEMGENE HLD4H, a medical-grade disinfectant from the UK containing Benzalkonium Chloride and Didecyldimethylammonium Chloride.

The service page lists viruses, bacteria and fungi, including COVID-19, RSV, H1N1, H5N1 and hand-foot-mouth virus, with a stated 99.99% efficacy, and lists approvals or endorsements from the Department of Medical Sciences, Mahidol University, NHS England and EN 14476:2013+A2:2019. The product page states 99.85% against COVID-19 within one minute. The manufacturer describes the product as broad-spectrum; no strain count is stated.

WHD's customers include hospitals, schools, malls, airports, offices, airlines, banks and residential buildings. WHD is based in Bang Khae, Bangkok 10160, and Don Mueang customers can book by phone or LINE. Service dates depend on the schedule, site conditions and water levels; same-day service cannot be promised. The current promotion includes a free CHEMGENE spray bottle and WELLGIENIC wet tissues, and a tax invoice is available.

For strong musty odours you can also ask about residential ozone disinfection as a complementary service.

Five Steps of Post-Flood Spraying for Don Mueang Shophouses and Homes

1. Survey: contact WHD by phone or LINE with photos, the height of the tide mark, the number of rooms and how the space is used.

2. Mud removal and washing: remove mud, rubbish and damaged items, wash floors, lower walls and furniture with clean water and detergent, and let them dry. Spraying always comes after this step.

3. Zoning and preparation: technicians divide the site into zones such as shopfront, kitchen, bathroom, bedrooms and stairs; food, utensils and personal items are stored away; people and pets leave the zone being sprayed.

4. Spraying: technicians spray and/or ULV-fog CHEMGENE HLD4H across flood-touched surfaces, walls up to the tide mark, under counters, table legs, rails, handles and high-touch points.

5. Re-entry: according to the service information, wait about 30 minutes before using the space normally. Follow the technicians' re-entry time on site, ventilate, and wipe food-contact surfaces with clean water as advised.

10 Reasons Theod Rachan Homes and Shops Should Disinfect After the Flood

1. Backflow water from ditches and canals is more likely to contain sewage than rain.
2. Days of standing water push germs deeper into materials and grout.
3. Food shops need confidence before reopening. See the spraying service
4. Small children play on floors and put things in their mouths.
5. Older adults and people with chronic illness face more serious gut and wound infections.
6. A medical-grade disinfectant that, per product information, covers viruses, bacteria and fungi.
7. Trained technicians know the spots people miss.
8. ULV fogging reaches corners that hand-wiping struggles with. Ask about ULV fogging
9. About 30 minutes before re-entry per the service information, so shops need not close for days.
10. Peace of mind for families and customers. Book a visit

Before and After: A Don Mueang Shophouse

Example Case: Nid's Shop Before Reopening

An illustrative example to explain the process, not a real customer review.

After the water drained, Nid and her husband shovelled out the mud, threw away soaked items, washed floors and walls to the tide mark and left every door open for a day. Then they sent photos to WHD on LINE to book spraying.

On the day, the family took their daughter and Nid's mother to a relative's house. Technicians zoned the shopfront, kitchen, bathroom and stairs, stored utensils in closed cupboards and sprayed. After the stated waiting time, the family returned, opened the windows and wiped food counters with clean water before cooking. Nid's mother, who had waded out with a foot cut, saw a doctor, because home disinfection never replaces medical care.

Recovery Checklist for Homes on Theod Rachan Road

Before spraying

• Switch off ground-floor power; have an electrician check if unsure.
• Wear rubber boots, gloves and a mask while removing mud.
• Discard food, medicine and drinks touched by floodwater, and ice from freezers that lost power.
• Remove mud, wash floors and walls to the tide mark, and dry within 24 to 48 hours where possible.
• Remove soaked or mouldy rugs, mattresses, cardboard and swollen plywood.

During and after spraying

• Everyone, including children, older adults and pets, leaves the zone being sprayed.
• Return at the time technicians give, then ventilate.
• Wipe food-contact surfaces with clean water as advised.
• Clean and disinfect water tanks before refilling; drink boiled or bottled water.
• Watch for fever, calf pain, severe diarrhoea, yellow eyes or red, swollen wounds, and see a doctor promptly.
• Monitor odour and mould over the following weeks and contact WHD if problems persist.

FAQ: Post-Flood Disinfection on Theod Rachan Road, Don Mueang

Q: The water only reached shin height. Do I still need disinfection?
A: Depth is not the only factor. Backflow from drains often carries sewage, and water standing for days leaves germs on floors, lower walls and furniture. Homes with small children or older adults, and food shops, should clean then disinfect.

Q: Do we need to leave during spraying?
A: People and pets should leave the zone being sprayed and return when technicians say. The service information gives about 30 minutes.

Q: Will spraying prevent leptospirosis?
A: It reduces germs on indoor surfaces, but leptospirosis is also caught outdoors while wading. Wear boots, cover cuts and see a doctor for any fever after wading.

Q: Does WHD serve Don Mueang?
A: WHD is based in Bang Khae, Bangkok, and takes Don Mueang bookings on 065-556-6294 or LINE @whd268. Dates depend on the schedule and road access.

Q: How long must a food shop close?
A: It depends on size and prior cleaning. Spraying each zone is quick, and the service information gives about 30 minutes before re-entry; WHD will confirm timing after the survey.

Theod Rachan Homes and Shops Can Be Safe Again: We Prevent and Eliminate Post-Flood Germs for You

Flood germs come in many kinds: bacteria, viruses and fungi. Once you have cleared the mud, let the WHD team spray CHEMGENE HLD4H, a broad-spectrum disinfectant according to the product information, to help prevent and eliminate germs on surfaces before your family moves back and your shop reopens.

Book Post-Flood Disinfection Now

Call 065-556-6294  |  LINE @whd268

World Health Disinfection, Bang Khae, Bangkok 10160.

Related Links and References

• Disinfection spraying service: https://www.worldhealthdisinfection.com/en/disinfection-service
• CHEMGENE HLD4H: CHEMGENE HLD4H product page
• Residential ozone disinfection: https://www.worldhealthdisinfection.com/en/residential-ozone-disinfection
• Daily News, standing water on Theod Rachan Road, Si Kan, Don Mueang (27 Sep 2026): https://www.dailynews.co.th/news/6225817/
• Government Public Relations Department, DDPM flood summary (as of 06:00, 7 Oct 2026): https://www.prd.go.th/th/content/category/detail/id/33/iid/548715
• CDC, Floods: https://www.cdc.gov/floods/
• WHO Fact sheets: https://www.who.int/news-room/fact-sheets
• Thai Department of Disease Control: https://ddc.moph.go.th/