The Bang Sai flood situation in early October 2026

According to Manager Online on 3 October 2026, communities in Bang Sai subdistrict had water about 1.80 metres deep, close to 2 metres in places, and residents were paddling boats out to buy food. Across Phra Nakhon Si Ayutthaya province, 16 districts and 48,704 households were flooded. The Chao Phraya Dam was releasing 2,500 cubic metres per second and the Rama VI Dam 616 cubic metres per second.

Those figures suggest the water in Bang Sai may not recede quickly, and when it does, homes that were submerged almost to the ground-floor ceiling will be left with a great deal of mud, sediment and sewage residue. This article is therefore written for two phases: while people are still living with the water, and when they are about to move back in.

The story below is a typical scenario drawn from situations that commonly follow floods. It does not describe any real individual.

Auntie Lek has sold noodles from the front of her riverside house in a Bang Sai community for over twenty years. When the water reached the ground floor, she moved her kitchen upstairs and used water stored in big clay jars to rinse vegetables and bowls. Some days the jars ran dry, and her son scooped water from outside the house to wash dishes, reasoning that everything would be dipped in boiling water anyway. The downstairs toilet was unusable, so the whole family shared a makeshift toilet upstairs and rinsed their hands in the same bowl of water.

Three weeks after the water receded, her son began to feel unusually tired, lost his appetite, felt sick and ran a low fever. Then his urine turned the colour of tea and the whites of his eyes went yellow. The doctor suspected viral hepatitis and asked questions Auntie Lek had not thought about: what water had the family cooked with during the flood, and was anyone else at home or in the community ill in the same way? The noodle shop had to close. Auntie Lek was worried not only about her son but about dozens of regular customers.

What is hepatitis A?

Hepatitis A virus belongs to the Picornaviridae family. It carries RNA and is a non-enveloped virus. It targets liver cells and causes acute inflammation of the liver. The World Health Organization (WHO) explains that the disease is closely associated with unsafe water and food, inadequate sanitation and poor personal hygiene, which is exactly the set of conditions a flood creates all at once.

Its toughness is worth understanding. Hepatitis A virus can survive in the environment for a long time, in water, on surfaces and in some foods. It tolerates acidity and resists many disinfectants better than enveloped viruses do. Heat at boiling point inactivates it, which is why basic post-flood advice is to drink boiled or sealed bottled water and eat freshly cooked food.

Unlike hepatitis B and C, hepatitis A does not become a chronic infection. Most people recover fully and are immune for life. But the illness can last weeks or even months, keeping people off work, and in older adults or those with existing liver disease it can be severe.

The good news is that there is a hepatitis A vaccine, which WHO describes as safe and effective. Food handlers and people with chronic liver disease should ask a doctor whether vaccination is right for them.

How hepatitis A spreads during and after a flood

Hepatitis A spreads by the faecal-oral route. Infected people shed large amounts of virus in their stool, and they shed the most before symptoms begin, so someone who looks perfectly well may be spreading it. A flood opens these routes:

• Drinking and household water. Sewage-laden floodwater gets into shallow wells, water jars, tanks and broken pipes. Using that water to drink, make ice, wash vegetables, rinse dishes or brush teeth is the single most important route.
• Uncooked food. Fresh vegetables, hand-cut fruit, dipping sauces, ice and drinks mixed with unsafe water, as well as shellfish gathered from contaminated water and eaten raw or undercooked.
• Infected food handlers. A cook in a community kitchen, restaurant or market stall who is infected but not yet ill can pass the virus via their hands to food that will not be heated again.
• Close living. Families sharing a makeshift toilet, rinsing hands in one bowl or staying in a shelter are more likely to pass it around.
• Surfaces after the water recedes. Mud and residue on kitchen floors, counters, cupboards, sinks and dishes may contain faecal contamination. Poorly cleaned utensils that go back into use are another route.

In riverside communities on the Chao Phraya like Bang Sai, where many homes sit beside the water and daily life is tied to the river, changing water habits during a flood takes a deliberate effort from the whole family.

Hepatitis A symptoms, and why the long incubation is dangerous

According to the CDC and WHO, the incubation period averages about four weeks and ranges from roughly two to seven weeks. Someone infected during the high water of early October could therefore fall ill anywhere from late October into November, when most people are back at work and no longer think of the flood as a possible cause.

Common symptoms include:

• marked tiredness, loss of appetite, nausea and vomiting
• low fever and pain under the right ribs
• tea-coloured urine and pale stools
• yellowing of the skin and eyes (jaundice), sometimes with itching
• diarrhoea in some people

Age changes the picture a lot. WHO notes that most young children who are infected have no obvious symptoms or only mild ones, while teenagers and adults are more likely to be clearly ill, often with jaundice. As a result, children in the household can quietly pass the virus to parents and grandparents.

People who need extra care include older adults, those with existing chronic liver disease such as hepatitis B or C or cirrhosis, people with weakened immunity, and pregnant women. They should see a doctor promptly if symptoms appear.

Anyone with yellow skin or eyes, dark urine, severe fatigue or vomiting so bad they cannot eat should see a doctor and mention that they were in a flooded area. A blood test is used to confirm infection. This article does not give medication or treatment advice, and it is wise to avoid self-medicating with drugs or herbal "liver tonics", because an inflamed liver needs a doctor's care. Anyone who is ill should not prepare food for others until a doctor says it is safe.

Other post-flood illnesses can also cause jaundice, notably severe leptospirosis, which usually starts with a high fever and calf pain after wading. Thailand's Department of Disease Control urges anyone who develops a fever after floodwater contact to see a doctor quickly.

Hepatitis A hotspots in homes, food shops and community kitchens

Because hepatitis A enters through the mouth, the key risk points are everything to do with water and food:

• Kitchens and sinks: counters, chopping boards, knives, dish racks, cutlery drawers and the lower cupboards that sat in water.
• Water containers: jars, buckets, tanks, ice chests and flasks that floodwater entered or that were filled with unsafe water.
• Street food stalls: carts, customer tables and chairs, condiment bottles, vegetable trays and prep areas.
• Toilets: both submerged ones and makeshift ones, which contaminate hands that then touch food.
• Flooded refrigerators: door seals, shelves and freezer compartments that are hard to clean and easy to overlook.
• Community spaces: pavilions, central kitchens, temples and food distribution points used by many people.

What hepatitis A costs families and small businesses

Health and time. Adults who fall ill often need weeks off work and are too tired for heavy labour, just when the house most needs repairing.

Income. For a food vendor like Auntie Lek, a family member with a foodborne illness means closing the shop and waiting until a doctor says cooking for others is safe again.

Customers and reputation. When word gets out that someone at a shop has hepatitis, customers hesitate. Showing that the shop has cleaned, disinfected and changed how it uses water helps it reopen with confidence.

Chains of infection. Because of the long incubation, by the time anyone knows there is a case, the virus may already have passed to others at home or in the community. Health officials may need to trace contacts and advise preventive measures for those close to the patient.

Why the usual clean-up is not enough for hepatitis A

1. Assuming a quick dip in hot water solves it. A brief scald may not be hot for long enough, and it does nothing for counters, condiment bottles or the cook's hands.
2. A final rinse in unsafe water. Washing dishes with detergent and then rinsing them in floodwater or contaminated jar water puts the virus straight back.
3. One shared bowl for handwashing. The bowl becomes a reservoir. Use running water from a container with a tap, or pour water over the hands, together with soap.
4. Keeping food and condiments that touched floodwater. The CDC advises discarding food that came into contact with floodwater, except certain commercially sealed cans that must be cleaned in a specific way before opening.
5. Cleaning only the ground floor. In homes where the kitchen moved upstairs, the upper floor is also a risk, because that is where the makeshift toilet and food preparation shared space.
6. Painting or re-flooring straight away. Mud must be removed and surfaces washed, dried and disinfected before repairs, or contamination simply gets sealed under new materials.
7. Hoping sunshine will do the job. Sun helps drying, but it never reaches under cupboards, into counter gaps or inside the fridge.

WHD post-flood disinfection spraying for Bang Sai homes and food shops

World Health Disinfection (WHD) provides a disinfection spraying service for homes, restaurants, schools, temples and other buildings. According to the service information, trained technicians spray and/or apply ULV (Ultra Low Volume) fogging, a fine mist that settles across surfaces, including the gaps under counters and cupboards that hands cannot reach. The disinfectant is CHEMGENE HLD4H, a medical-grade disinfectant from the United Kingdom containing Benzalkonium Chloride and Didecyldimethylammonium Chloride.

Straight talk about hepatitis A. According to the product and service information, the disinfectant is broad-spectrum, covering viruses, bacteria and fungi. The organisms it names are SARS-CoV-2 (COVID-19), Human Coronavirus 229E, RSV, influenza H1N1 and H5N1, HIV, norovirus, hand-foot-and-mouth virus, vaccinia virus, mycobacteria, Salmonella and Bordetella pertussis. The service page states 99.99% effectiveness and the product page states 99.85% against COVID-19 within one minute. Hepatitis A is not on that list, so we make no claim of a tested kill result against it. What we can say is that hepatitis A belongs to the virus group the product says it covers, and that WHO and the CDC advise cleaning and then disinfecting flood-contaminated surfaces. If a restaurant or organisation wants test data for this specific virus, ask WHD directly.

One more point matters for a germ that enters through the mouth: spraying surfaces does not make drinking water safe. Drinking water must come from a safe source, be boiled, or come in sealed bottles. Spraying also does not replace vaccination or handwashing with soap.

The service page lists approvals and endorsements from Thailand's Department of Medical Sciences, Mahidol University, NHS England and EN 14476:2013+A2:2019. Customers include hospitals, schools, shopping malls, airports, offices, airlines, banks and residential buildings.

How the service works

1. Book. Call 065-556-6294 or LINE @whd268. Say whether it is a home, a restaurant or a central kitchen, how high the water came, and where food is prepared.
2. Prepare. Remove mud, wash floors, walls, counters, cupboards and sinks, throw away food and condiments that touched floodwater, and remove food containers and personal items or pack them into closed boxes.
3. Technicians spray. Kitchens, food-prep areas, bathrooms and high-touch surfaces are treated. Everyone leaves the zone being sprayed.
4. Wait, then return. According to the service information, the space can be used normally after about 30 minutes. Follow the technicians' re-entry time, and rinse food-contact surfaces with clean water as they advise before cooking.

Spraying is the step after mud removal and washing, not a substitute for them. We do not claim it leaves no residue at all, and anyone who is unwell must see a doctor.

10 reasons Bang Sai homes and food shops should book spraying after the flood

1. Homes were under almost two metres of water, so far more surface area was exposed than in an ankle-deep flood. Thorough disinfection is worth it.
2. The kitchen is the heart of the risk. Germs that enter through the mouth, like hepatitis A, start from food-contact surfaces.
3. Fine mist reaches under counters and cupboards, where mud collects and cloths cannot reach.
4. A product stated to cover several germ groups. After floods there are viruses, sewage bacteria and fungi. Read more on the disinfection service page.
5. Food shops can reopen with confidence and explain to customers exactly what was done.
6. Trained technicians mean exhausted families do not mix chemicals themselves.
7. Short turnaround: according to the service information, about 30 minutes before the space can be used.
8. Suits community spaces such as pavilions, central kitchens and temples used by many people.
9. Endorsements you can check, and organism-specific test data you can request from WHD.
10. Tax invoices and a promotion. According to the service information, you receive a CHEMGENE spray bottle and WELLGIENIC wet tissues. Book the service.

Before and after: a kitchen ready to cook again

Example case: a riverside noodle shop in Bang Sai

This example case continues the opening scenario. It is assembled from common situations and is not a review from any particular customer.

After Auntie Lek's son came under a doctor's care, health officials advised everyone in the house to wash hands strictly with soap and clean water, use boiled or bottled water for cooking, and keep the sick person away from preparing food for others. Auntie Lek closed the shop temporarily to rebuild her kitchen routine from scratch.

The family threw away noodles, vegetables, condiments and ice that might have touched floodwater. They scrubbed the counters, sink, pots and the noodle cart, cleaned the water jars and switched to water they trusted. Then they booked WHD to spray the ground floor, kitchen, bathroom and the area used as a makeshift toilet. Everyone waited outside during spraying. When the technicians' time was up, Auntie Lek rinsed food-contact surfaces with clean water as advised and set up her kitchen again.

When she reopened, she put up a small sign saying the shop cooks with clean water and has been cleaned and disinfected since the flood. Many regulars came back, and some asked about the steps so they could follow them at home.

Hepatitis A prevention checklist, during the flood and after the water drops

While still living with the water

• Drink boiled or sealed bottled water, and use safe water for ice, toothbrushing and washing vegetables.
• Eat freshly cooked food. Avoid raw vegetables, raw food and undercooked shellfish.
• Wash hands with soap and running water before cooking, before eating and after using the toilet.
• Bag human waste and tie it tightly as local authorities advise; never defecate into floodwater.
• If anyone develops yellow skin or eyes or dark urine, see a doctor and stop them preparing food for others.

Before spraying

• Remove mud and wash floors, walls, counters, cupboards, sinks and the fridge with clean water and detergent.
• Throw away food, condiments, medicines and anything that touched floodwater.
• Clean water jars and tanks following local authority advice.
• Open doors and windows to dry the house. Show the technicians the food-prep areas and any makeshift toilet spots.

After spraying

• Re-enter at the time the technicians give and ventilate.
• Rinse food-contact surfaces and utensils with clean water before use.
• Set up running-water and soap handwashing in the kitchen and by the toilet.
• Ask a doctor about hepatitis A vaccination, especially food vendors and people with chronic liver disease.
• Keep watching household members for symptoms for several weeks after the water drops, because the incubation period is long.

Frequently asked questions about hepatitis A and disinfection spraying

Does CHEMGENE HLD4H kill hepatitis A?
Hepatitis A is not on the list of organisms the website names, so we make no direct test claim. The product is stated to cover viruses, bacteria and fungi. If you need test data for this virus, ask WHD.

The water went down weeks ago. Should I still worry?
Keep watching for symptoms. The incubation period averages about four weeks and can stretch to around seven. If you notice yellow skin or eyes or dark urine, see a doctor and mention the flood.

After spraying, can we drink tap or well water?
No. Spraying treats surfaces; it does not make drinking water safe. Drink boiled or bottled water until local authorities confirm the supply is safe.

Can a restaurant reopen immediately after spraying?
Re-enter at the technicians' time, rinse food-contact surfaces and utensils with clean water first, and make sure no food handler is unwell.

The children have no symptoms. Does that mean they are not infected?
Not necessarily. WHO notes young children often have no obvious symptoms but can still spread the virus, so soap handwashing matters for everyone.

Can we get the hepatitis A vaccine after a flood?
Ask a doctor, who will consider each person's age, history and risk.

The house smells musty and mould is appearing. What should we do?
Dry the house completely first. According to the service information, the spraying disinfectant is stated to cover fungi. For musty air, the residential ozone disinfection service can be a complementary option.

Get the kitchen ready before you cook for the people you love

Talk to WHD about post-flood disinfection spraying for homes, food shops, community kitchens and temples in Bang Sai and across Ayutthaya.

Book disinfection spraying with WHD

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

Related links

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

References

• Manager Online (3 Oct 2026), flooding in Bang Sai subdistrict and Phra Nakhon Si Ayutthaya: mgronline.com
• WHO fact sheet, Hepatitis A: who.int/news-room/fact-sheets
• CDC Floods: cdc.gov/floods and CDC Hepatitis A: cdc.gov/hepatitis-a
• Thailand Department of Disease Control: ddc.moph.go.th