A typical scenario: eight days underwater at Ongkharak Old Market

According to News1live, floodwater entered the old canal-side market at Ongkharak at around 8 p.m. on 25 September 2026 and stayed until 2 October 2026, roughly eight days. In front of the shops the water stood about knee-high, and it was deeper along the canal. Toilets could not be used, older residents and young children found it hard to reach help, and the sandbags people stacked together could not hold back the water.

What follows is an example case built from situations that commonly arise after floods in old markets like this. It is not an interview with a real person.

Auntie Sri (not her real name) has run a small grocery in a two-storey wooden shophouse for most of her life. When the water came, she moved what she could upstairs and stayed there with her toddler grandson. The ground-floor bathroom was submerged, so the household got by with buckets and the same few towels for days. Nothing dried properly; every cloth smelled musty.

After the water drained she shovelled mud in flip-flops, and within a week she had a red, moist rash between her toes. Her grandson's nappy rash refused to clear, and her brother, who wears dentures, complained of sore cracks at the corners of his mouth. The family assumed it was simply "water-rotted feet" and an ordinary nappy rash, until a visiting public health volunteer suggested a check-up. Some of the symptoms turned out to be consistent with a yeast infection of the Candida type, which thrives in exactly this kind of damp.

The important lesson is that the germ did not simply arrive with the water. The conditions after the flood gave it room to grow: wet fabric, stale air, softened skin and limited hygiene. Those are things a family can control once they understand them.

What is Candida, and why is it called a fungus of damp places?

Candida is a genus of yeasts, single-celled fungi with a round or oval shape, quite different from the thread-like moulds that form black spots or fuzzy patches on walls. The most common species is Candida albicans; others include Candida glabrata, Candida parapsilosis and Candida tropicalis. Infections caused by these yeasts are known collectively as candidiasis.

In healthy people, Candida lives on the skin, in the mouth, in the gut and in the vagina without causing harm, kept in balance by our normal bacteria and the immune system. Trouble starts when that balance tips: skin stays wet for long periods, heat and humidity build up, immunity drops, or certain medicines reduce the protective bacteria. The yeast then multiplies and causes rashes, sores or white coatings.

Unlike many flood-related germs, Candida usually does not come from the floodwater itself. It is an opportunist that wakes up when conditions suit it. Even so, yeast can survive for a time on towels, sponges, sink edges and bathroom surfaces, so it can pass between household members, particularly through shared personal items.

In hospitals, the US CDC watches a species called Candida auris closely because it can persist on surfaces, a reminder that surfaces matter for yeasts more than most people assume.

Why Candida gets the upper hand after floods

Flooding lines up almost every condition a yeast could want, all at the same time.

1. Humidity that lingers for weeks

Wooden shophouses and older canal-side buildings dry slowly. Water soaks into timber, plaster and the space beneath floors, so indoor humidity stays high. The WHO and CDC advise cleaning and drying flooded buildings as quickly as possible, generally within 24 to 48 hours, to limit fungal growth. In a place that stayed flooded for eight days, that window had long passed.

2. Skin softened by hours in water

People who wade or work in mud for hours develop soft, waterlogged skin between the toes, on the soles and in body folds. The protective outer layer breaks down, and yeasts and bacteria settle in more easily. What locals call "water-rotted feet" often starts as irritation from wetness, but it can become infected by fungi or bacteria if it is not looked after.

3. Unusable toilets and too little clean water

When bathrooms are underwater, bathing, changing clothes and washing hands all become difficult. Damp underwear, nappies that are not changed often enough and towels shared by several people are exactly what yeast likes.

4. Fabric that never fully dries

During long spells of rain, laundry dried indoors stays slightly damp and musty. Moisture trapped in fibres supports many microbes, yeasts included.

5. Stress, poor sleep and harder-to-control illness

Irregular meals, poor sleep and missed medicines make diabetes harder to control, and high blood sugar is a known risk factor for candidiasis.

6. Antibiotics after other infections

Antibiotics prescribed for flood-related infections are important, but they can reduce normal bacteria and trigger thrush in some people. Report new symptoms to your doctor.

Where yeasts and moulds hide in shophouses and canal-side shops

Old market shophouses share a familiar layout: a narrow shopfront, a long, dim interior, a storeroom and a bathroom at the very back with little airflow. Pay particular attention to:

• Bathrooms and shower areas, especially toilet rims, grout lines, water scoops, showerheads and spots where water pooled after the flood.
• Towels, bath mats, doormats and sponges that have been wet again and again.
• Mattresses, pillows and fabric seat cushions that touched water or sat in very damp rooms.
• Wooden cabinets and the lower shelves of stock displays, plus corners sunlight never reaches.
• Boots, canvas shoes and socks used for wading and never properly dried.
• Children's toys, bottles, teats and seat cushions left in damp areas.
• Lower walls and wooden floors that still hold moisture even when the surface looks dry.

These spots usually hold moulds and bacteria too, so clean, dry and only then disinfect.

Candida symptoms worth watching for after a flood

Symptoms depend on where the infection develops. The examples below are for awareness only; diagnosis belongs to a doctor.

Skin folds

A moist, red rash with fairly clear edges, often with small red spots or bumps scattered around it (doctors call these satellite lesions). It itches or stings and is common in the groin, under the breasts, under the belly, in the armpits and between fingers or toes.

Between the toes and around the nails

White, soggy, peeling skin that may smell and itch. People whose hands are in water all day, such as dishwashers, fresh-market vendors and volunteers cleaning houses, can develop red, swollen skin around the nail folds.

Nappy rash in babies

A bright red rash in the nappy area that spreads into the creases and has scattered spots around the edge, often not improving with ordinary nappy cream. A paediatrician should take a look.

Oral thrush

Creamy white patches on the tongue, inner cheeks or palate that are hard to wipe away and may leave red areas underneath. It is seen in babies, denture wearers and people with weaker immunity, sometimes with cracks at the corners of the mouth.

Vaginal yeast infection

Intense itching, thick white discharge and burning when passing urine. See a doctor to rule out other infections.

When to seek medical care promptly

• Fever, a rapidly spreading rash, painful hot swelling or pus, which may mean a bacterial infection as well.
• A baby whose mouth is so sore that feeding becomes difficult, or who becomes drowsy.
• People with diabetes, cancer, HIV or those on immune-suppressing medicines who notice signs of fungal infection.
• Pain or difficulty swallowing.
• Wounds on the feet after wading, together with fever, calf pain or red eyes, which can signal more serious conditions such as leptospirosis. See a doctor immediately.

Avoid buying antifungal or steroid creams on your own without advice, because some products can make fungal rashes worse.

Who is most at risk of candidiasis after the water recedes?

• Babies and young children who spend long hours in nappies, have delicate skin and put things in their mouths.
• Older adults, especially denture wearers and people who are bedridden or depend on others for care.
• People with diabetes, since high blood sugar helps yeast grow.
• Pregnant women, because of hormonal changes.
• People with weakened immunity, such as those receiving chemotherapy, taking immune-suppressing drugs, or living with HIV that is not well controlled.
• People recently given antibiotics by a doctor.
• Workers whose hands or feet are wet all day: market vendors, cleaners, volunteers and rescue staff.
• People with larger body folds, where heat and moisture collect.

At Ongkharak, where older people and children struggled to reach help, these groups deserve attention first, both for personal hygiene and for the condition of the home around them.

The hidden costs of leaving damp and fungi in a shop

Health

Skin infections can sound minor, yet constant itching ruins sleep, and broken skin can let bacteria in. For small children and older adults, a sore mouth means eating less at the very time the body needs energy to recover.

Money and income

A vendor with a painful rash on her hands or feet cannot work at full pace. There are clinic visits, travel costs and lost sales while the shop stays closed, and stock in a damp storeroom keeps deteriorating every day the humidity remains.

Customer confidence

A customer who smells mould and sees stained walls may not return. Visible cleanliness is part of reopening.

Why familiar fixes are not enough on their own

• Running a fan dries the surface, but moisture stays in timber, under floors and inside cushions, and a fan can blow mould spores around.
• Pouring bleach over dirty surfaces wastes much of its effect, because bleach is used up by mud and organic matter. The CDC also warns never to mix bleach with ammonia or other cleaners, because dangerous gases can form.
• Air freshener masks odours for a while but does not reduce germs.
• Painting over mould only hides it; it returns if the wall is still damp.
• Drying laundry indoors leaves moisture in the fibres. Wash at the hottest temperature the fabric allows and dry thoroughly.
• Small spray bottles used spot by spot are useful for high-touch points but cannot cover an entire shop, including shelves, walls and hard-to-reach corners.

None of these is wrong; each is only part of the job. What is often missing is systematic, safe disinfection of the whole area.

WHD disinfection spraying: the final step after mud removal and drying

World Health Disinfection (WHD) offers a disinfection spraying service for homes, shops, buildings and businesses. According to the service information, trained technicians apply disinfectant by spraying and/or ULV (Ultra Low Volume) fogging, a fine mist that helps the product reach surfaces and corners evenly.

The product used is CHEMGENE HLD4H, a medical-grade disinfectant from the United Kingdom containing Benzalkonium Chloride and Didecyldimethylammonium Chloride, both quaternary ammonium compounds. According to WHD's product and service information, it is broad-spectrum, covering viruses, bacteria and fungi. The service page states 99.99% efficacy, and the product page states 99.85% against the COVID-19 virus within one minute.

An honest word about Candida

The organisms WHD lists include SARS-CoV-2 (COVID-19), RSV, influenza H1N1, avian influenza H5N1, hand-foot-mouth virus, norovirus, Salmonella, the whooping cough bacterium, mycobacteria, bacteria in general and fungi or mould. Candida is not named individually. So we do not claim a tested kill result for Candida specifically. What we can say is that Candida belongs to the fungi group the product says it covers, and that the WHO and CDC advise cleaning and then disinfecting surfaces contaminated by floodwater. If your business needs test documentation for a particular organism, for example a clinic, a massage shop or an elder-care home, ask the WHD team for the test data for that organism.

The service page also lists approvals and references including the Thai Department of Medical Sciences, Mahidol University, NHS England and EN 14476:2013+A2:2019, with customers ranging from hospitals, schools and malls to airports, offices, airlines, banks and residential buildings.

How the spraying process works for a shophouse after a flood

1. Book and describe the site. Share the floor area, number of floors, type of shop and how high the water reached, by phone on 065-556-6294 or LINE @whd268.
2. Prepare the area. Remove damaged items, shovel out mud, wash floors and walls with clean water and detergent, open doors and windows and dry as much as possible. Put food, dishes, children's toys and personal items away in closed storage.
3. Everyone leaves the zone, including children, older relatives and pets, while technicians are spraying.
4. Technicians spray and/or ULV-fog floors, lower walls, shelving, bathrooms, storerooms and high-touch points such as door handles, stair rails, counters and the cash desk.
5. Wait as instructed. According to the service information, the usual wait is about 30 minutes before the space is used normally. Always follow the re-entry time the technicians give on the day.
6. Afterwards, ventilate, wipe food-contact surfaces with clean water before use, and keep the space dry.

According to the service information, customers receive a free CHEMGENE spray bottle and WELLGIENIC wet wipes, and a tax invoice is available. If a musty smell lingers in the air after surface disinfection, you can also consider WHD's residential and building ozone service as a complementary option.

10 reasons old-market shops should book disinfection spraying after a flood

1. Canal-side shophouses dry slowly, giving yeasts and moulds more time to grow than in a typical house.
2. Shops are places where strangers touch the same surfaces, from counters and change to products, so disinfecting shared touch points helps limit spread.
3. ULV mist reaches corners that cloths and small bottles cannot, such as under shelves and behind cabinets.
4. A medical-grade product, CHEMGENE HLD4H, stated in the product information to cover viruses, bacteria and fungi.
5. Trained technicians know how much to apply, where the risk points are and how to protect themselves and occupants.
6. Short downtime. According to the service information, the usual wait is about 30 minutes, so a shop can reopen sooner.
7. Less burden on exhausted families. Older owners who have spent days cleaning do not have to disinfect an entire shop alone.
8. Customer reassurance. Telling customers the shop has been cleaned and professionally disinfected is a message that brings people back.
9. Paperwork and tax invoices for registered businesses or anyone who needs proof of site care.
10. Advice before you commit. Ask about the space, the steps or the test data for a germ you are worried about via the disinfection service page, by phone on 065-556-6294 or LINE @whd268.

Before and after: a shophouse handled step by step

This comparison is illustrative; real results depend on the building and its upkeep.

Example case: a Thai dessert shop in a wooden canal-side shophouse

This is an illustrative example to show how the work fits together, not a review from a real customer.

Nid runs a Thai dessert shop across two wooden units. After the flood, the back kitchen and bathroom smelled strongly musty, and two of her staff developed rashes on their hands from washing utensils in water day after day. Nid took them to a doctor first, then planned the shop's recovery.

The team threw out all flour and ingredients that had touched the water, cleared the mud, scrubbed floors with detergent and ran fans with the windows open for two days. Only then did Nid book disinfection spraying. The technicians asked her to put all utensils away, turn off the gas and have everyone leave during the work. After waiting the time the technicians specified, Nid wiped the food-preparation counters with clean water before making desserts again.

What helped most was the order: clean, dry, then disinfect, with staff health looked after alongside.

Recovery checklist to reduce Candida and other fungi after a flood

Look after your body

• Wash hands and feet with soap after every exposure to floodwater, and dry between the toes completely.
• Change socks and underwear daily, or immediately if they get wet.
• Wear rubber boots and gloves when wading or clearing mud.
• Change babies' nappies more often and let the skin air-dry between changes.
• Denture wearers should clean dentures daily as their dentist advises.
• People with diabetes should keep taking medicines and checking blood sugar as their doctor recommends, even during a crisis.
• Do not share towels.

Look after the home or shop

• Remove soaked items that cannot be cleaned, such as flooded mattresses, carpets and cardboard boxes.
• Shovel out mud and wash floors and walls with clean water and detergent.
• Ventilate and dry everything as fast as you can.
• Wash all wet fabric and dry it completely before storing.
• Have an electrician check wiring before switching appliances back on.
• Book disinfection spraying once washing and drying are done.
• Afterwards, keep watching for damp; if walls stay wet or mould returns, find the source of the leak.

Frequently asked questions about Candida and post-flood spraying

Can you catch Candida from floodwater?

Most Candida already lives on and in our bodies, so floodwater is not the main source. Floods create the wet, stuffy, low-hygiene conditions that let yeast overgrow. Yeast can also survive on towels and bathroom surfaces for a while, so avoid sharing personal items.

How is "water-rotted feet" different from a Candida infection?

The early stage is often simple irritation from skin that stayed wet too long. Left alone, it can become infected by Candida, by the fungi behind athlete's foot, or by bacteria. They look similar, so let a doctor or pharmacist assess it.

Will disinfection spraying treat a fungal skin rash?

No. Spraying treats surfaces in a building, not people. Anyone with symptoms should see a doctor. Spraying reduces germs on surfaces the household touches, which is a separate part of prevention.

Does CHEMGENE kill Candida?

According to the product information, CHEMGENE HLD4H covers fungi, but Candida is not named specifically on WHD's pages. If you need test documentation for this organism, ask WHD directly on 065-556-6294 or LINE @whd268.

Should I clean first or spray first?

Always clean first: remove damaged items, clear the mud, wash surfaces and dry them. Disinfectants work best on clean surfaces; mud and grime block them from reaching germs.

Can young children and older relatives stay inside during spraying?

No. Everyone, including pets, should leave the zone being sprayed and return when the technicians say so. No disinfectant should be described as leaving zero residue, so wipe surfaces that children mouth or that touch food with clean water before use.

Ready to get your home or shop clean again?

After a flood, damp is the silent enemy, and Candida is one of the organisms that takes advantage of it. Wash, dry, care for your skin and finish with professional surface disinfection using a medical-grade, broad-spectrum product.

Book post-flood disinfection spraying

Phone 065-556-6294 · LINE @whd268 · worldhealthdisinfection.com

Related links and references

WHD links

• WHD disinfection spraying service
• CHEMGENE HLD4H disinfectant
• Residential and building ozone disinfection

References

• News1live report on flooding at Ongkharak Old Market, 25 September to 2 October 2026: news1live.com
• World Health Organization: Fact sheets
• US CDC: Floods and Candidiasis
• Department of Disease Control, Thailand: ddc.moph.go.th