A typical scenario: the cough in a classroom turned shelter

This is an illustrative example case based on situations commonly seen in flood areas. It does not describe real individuals.

Prae is a young mother living in a riverside village in Bang Pla Ma district. When the water started rising in late September, her family moved her two-month-old daughter, her four-year-old son and her grandmother, who is nearly eighty, to a school building on higher ground. One classroom held five or six families. Everyone shared the same toilets, donated cups and spoons sat together on a single table, and sleeping mats were laid edge to edge because there was no other space.

A few days later, a primary-school boy from the next family developed a runny nose and a mild cough. Everyone assumed it was a cold from being caught in the rain. A week after that, the cough changed. It came in long bursts that turned his face red, ending with a loud, gasping intake of breath, and sometimes he coughed until he vomited. The coughing was worst at night. Prae became worried, because her daughter was far too young to have finished her vaccines, and she remembered a health worker once using the word "pertussis".

When staff from the local health-promoting hospital visited, the boy was referred to a doctor. Nearby families were told to watch for symptoms, to have coughing children wear masks, and to keep babies as far from anyone coughing as possible. Prae took her daughter to be checked as advised. Her question, shared by many: once the water goes down, how do we make homes, classrooms and nurseries as safe as possible for very small children?

The 2026 Suphan Buri floods: nine districts affected

According to the Department of Disaster Prevention and Mitigation (DDPM) situation report of 2 October 2026, as published by Bangkok Biz News, nine districts of Suphan Buri province were affected: Bang Pla Ma, Song Phi Nong, Don Chedi, Si Prachan, Mueang Suphan Buri, Sam Chuk, Doem Bang Nang Buat, U Thong and Dan Chang, covering 18,987 households, with water levels still rising at that time. Thansettakij also reported that Suphan Buri was on the list of areas to watch for water released from the Chao Phraya Dam.

Behind that number are homes, temples, schools, nurseries and shops that must be restored once the water recedes. Meanwhile many families stay with relatives, in shelters, or crowd into one upstairs room, exactly the settings where respiratory infections pass easily.

This article does not claim there is a pertussis outbreak in Suphan Buri; we have no such data. The aim is to help families and carers recognise the disease early and plan the clean-up of shared spaces properly.

What is whooping cough (Bordetella pertussis)?

Whooping cough, or pertussis, is a respiratory infection caused by Bordetella pertussis, a small, rod-shaped Gram-negative bacterium. It attaches to the lining of the airways, specifically to the tiny hair-like cilia that sweep mucus out of the lungs, and releases several toxins. These toxins damage the cilia and inflame the airways, leaving thick mucus that is hard to clear. The result is the violent, repeated coughing fits that give the disease its name.

Humans are the only known reservoir of Bordetella pertussis. Unlike leptospirosis bacteria or faecal germs, it does not live in soil or floodwater. It spreads mainly from person to person through droplets released when an infected person coughs, sneezes or talks at close range. People are most contagious early in the illness, when symptoms look like an ordinary cold, which is why those around them rarely take precautions in time.

Pertussis is highly contagious; WHO and the US CDC describe a high chance of infection among unprotected household contacts. Protection from vaccination or past infection fades over the years, so teenagers and adults can catch it again and carry it home to an infant.

Thailand, like many countries, has seen periods of increased reports in recent years; check the Department of Disease Control for current figures.

Why floods raise the risk of Bordetella pertussis spreading

The germ is not waterborne, but floods change daily life in ways that favour respiratory disease.

1. Crowding. Temporary shelters in schools, temples and community halls often hold far more people than they were designed for. With almost no distance between sleeping spots, one person's cough easily reaches others.
2. Poor ventilation. During heavy rain, doors and windows are kept shut against wind and water. Air does not circulate, and droplets linger.
3. Missed vaccine appointments. When roads are cut or local clinics are affected, some children miss a dose of the combined diphtheria, tetanus and pertussis vaccine, leaving a gap in protection.
4. Shared items. Cups, spoons, feeding bottles, handkerchiefs and donated toys are often passed around without thorough washing. Droplets are the main route for pertussis, but hands that touch fresh mucus and then a face or a baby are a secondary route worth closing.
5. Early symptoms are overlooked. In the chaos of evacuation, a runny nose and cough look like a cold from the rain. By the time anyone suspects pertussis, it may already have spread.

That is why public health guidance for shelters stresses symptom screening, separating the sick, masks, handwashing, fresh air and regular cleaning of frequently touched surfaces. Disinfection spraying is one tool for that last part.

The three stages of whooping cough

The incubation period is usually around 7 to 10 days, though it can be shorter or longer. The illness then moves through three stages.

Stage 1: the catarrhal (cold-like) stage. Lasting about one to two weeks, it brings a runny or blocked nose, sneezing, a low or absent fever and an occasional mild cough. This is the hardest stage to tell apart from a common cold, and the most contagious.

Stage 2: the paroxysmal stage. This can last several weeks. The patient has bursts of rapid coughing without time to breathe, the face may turn red or bluish, and at the end of a fit there may be a loud "whoop" as air is drawn in. Vomiting and exhaustion after coughing are common. Between fits the person may look quite well. Attacks are often worse at night.

Stage 3: the convalescent stage. The cough slowly eases, but some people keep coughing for weeks or months, and a new cold can bring the coughing fits back. This long tail is why pertussis is sometimes called the "hundred-day cough".

Warning signs in babies

Infants, especially those under six months, may never whoop. Instead they may have pauses in breathing, turn blue, feed poorly or struggle to breathe. These signs need a doctor immediately. Babies in this age group face the highest risk of complications such as pneumonia and often need hospital care.

In teenagers and adults

Often just a cough lasting weeks without a whoop, so it goes undiagnosed while still spreading at home. Adults coughing for more than two weeks, especially near a baby, should see a doctor.

Important: If a child or adult has long coughing fits, coughs until vomiting, or has coughed for more than two weeks, or if a baby has breathing pauses, turns blue or cannot feed, seek medical care promptly. Diagnosis and antibiotic treatment are decisions for a doctor. This article is general information, not personal medical advice.

Who is most at risk in a flood area

• Newborns to six-month-olds, who have not completed their vaccine series and are most likely to become seriously ill.
• Children with incomplete or delayed vaccinations, particularly when the flood cut off access to clinics.
• Pregnant women, because their newborns will be in constant close contact with them. A vaccine given in pregnancy on a doctor's advice can pass protection to the baby.
• Older people and those with chronic illness such as asthma, lung disease or weakened immunity.
• Teachers, carers and shelter volunteers in close daily contact with many people.

Vaccination is the first line of defence, not spraying

This needs saying plainly: the most important protection against pertussis is vaccination. In Thailand, a combined vaccine that includes pertussis is part of the national childhood immunisation programme, with several doses starting in the first months of life and boosters in early childhood. Parents should check the mother and child health book to see whether each child is up to date. If a dose was missed during the flood, contact the local health-promoting hospital or district hospital to catch up as soon as possible. Pregnant women and adults who will be close to a newborn should ask a doctor which vaccines are right for them.

Spraying, handwashing, masks and ventilation support this; none replaces vaccination.

Where pertussis germs collect in homes and buildings after the flood

Bordetella pertussis is not a hardy environmental survivor like mould spores. Outside the body it lasts only a short time on surfaces. But in a room where people are coughing and sneezing all day, fresh droplets are deposited constantly. Pay particular attention to:

• Desks, chairs, stair rails, door handles and light switches in classrooms used as shelters.
• Shared mats, mattresses, pillows and blankets.
• Toys, crawling mats, cots and changing tables in child development centres.
• Taps, washbasins and shared toilets.
• Feeding bottles, teats, cups and shared utensils. These must be washed and sanitised by methods suitable for food-contact items, not sprayed with a surface disinfectant.

Flooded buildings also carry sewage bacteria and mould, so a good plan covers both the germs that came with the water and those that came with people.

The real cost for families and organisations

Health and money. Pertussis in a young child can mean a hospital stay, with a parent at the bedside while the house still waits to be cleaned. Travel, food and lost wages pile on top of house repairs and crop losses, a heavy burden for farming households across Suphan Buri.

Time and trust. Pertussis takes a long time to clear, and a doctor may advise staying away from school or work while contagious. For schools and nurseries, a cluster of sick children after reopening makes parents reluctant to send children back. Showing that the building was washed and then disinfected systematically helps rebuild confidence and eases family worry about a baby or grandparent at home.

Why the usual quick fixes fall short

Wiping with plain water removes dust and dirt but does not disinfect. Using one cloth across many surfaces can even move germs from one spot to the next.

Home-mixed bleach by guesswork. At the right dilution bleach disinfects clean surfaces, but mixed too strong its fumes irritate airways, a poor choice near babies or someone coughing; too weak, it does little. Never mix it with toilet cleaners or ammonia.

Air freshener and floor-only mopping miss the point: scent does not reduce germs, and cough droplets land on tables, bed edges, toys and handrails at a child's reach.

Skipping the mud removal. Every disinfectant works best on a clean surface. If mud and grime still coat it, the product cannot reach the germs. That is why the CDC and WHO always advise cleaning first and disinfecting second.

How WHD post-flood disinfection spraying helps against whooping cough

World Health Disinfection (WHD) provides a disinfection spraying service carried out by trained technicians. According to the service information, the team uses spraying and/or ULV (Ultra Low Volume) fine-mist fogging so that the disinfectant reaches surfaces throughout a room, including corners that are hard to wipe by hand.

The product used is CHEMGENE HLD4H, a medical-grade disinfectant from the United Kingdom containing Benzalkonium Chloride and Didecyldimethylammonium Chloride, both quaternary ammonium compounds.

Bordetella pertussis is on the product's listed organisms

According to the product and service information on the WHD website, CHEMGENE is described as broad-spectrum, covering viruses, bacteria and fungi, and the organisms listed include Bordetella pertussis (whooping cough), together with SARS-CoV-2 (COVID-19), Human Coronavirus 229E, RSV, influenza H1N1 and H5N1, HIV, norovirus, hand-foot-and-mouth virus, vaccinia virus, mycobacteria and Salmonella. The service page states 99.99% efficacy, and the product page states 99.85% against COVID-19 within one minute (per product and service information).

The service page also lists approvals and endorsements from the Department of Medical Sciences, Mahidol University, NHS England and the EN 14476:2013+A2:2019 standard. If you need the test documents for a particular organism, ask WHD for them directly.

What spraying can and cannot do

Spraying reduces germs on surfaces at the time of treatment, which suits preparing shelters-turned-classrooms, nurseries and homes before reopening.

Spraying does not treat anyone who is ill, does not create immunity, and does not stop a new patient from coughing out fresh droplets. As soon as someone coughs in the room, new contamination appears. Spraying must therefore go hand in hand with vaccination, separation of the sick as advised by a doctor, masks, handwashing and open windows.

The WHD post-flood spraying process

1. Contact and booking. Tell the team the type of building, its size, the number of rooms and any special concerns, such as young children or recent coughing illness, via LINE @whd268 or phone 065-556-6294.
2. Remove mud and clean first. The owner removes mud, rubbish and damaged items, washes floors, walls and furniture, and lets everything dry as much as possible. Spraying always comes after this step.
3. Prepare the area. Put away food, feeding bottles, food containers, toys children put in their mouths and personal items in closed storage. Switch off non-essential electrical equipment.
4. Everyone leaves. During application, residents, children, older people and pets must leave the sprayed zone.
5. Technicians apply the disinfectant by spraying and/or ULV fogging, focusing on frequently touched surfaces.
6. Wait for the re-entry time. The service information says to wait about 30 minutes after spraying before using the space normally. Follow the exact time the technicians give for each job, and open windows to ventilate before going back in.
7. Keep it up. Wipe high-touch points daily, wash hands often and keep air moving.

According to the service information, WHD's customers include hospitals, schools, shopping malls, airports, offices, airlines, banks and residential buildings. A current promotion includes a free CHEMGENE spray bottle and WELLGIENIC wet tissues with the service, and tax invoices are available.

10 reasons to disinfect young children's spaces after the flood

1. Pertussis is on the list. CHEMGENE product information names Bordetella pertussis among the organisms covered.
2. Reset classrooms used as shelters before pupils return, reducing germs left from weeks of crowding.
3. Nurseries need the most care because toddlers mouth objects and have not finished their vaccines. Talk to the disinfection service team about a site-specific plan.
4. Several germ groups in one visit: respiratory viruses, bacteria and the fungi that follow floods.
5. ULV mist reaches awkward places such as table legs, under beds and surfaces hand-wiping misses.
6. Trained technicians mean no guesswork with home-mixed chemicals.
7. Short downtime: about 30 minutes after spraying, per the service information, or as the technicians advise.
8. Listed approvals and endorsements including the Department of Medical Sciences and EN 14476.
9. Parent confidence: schools and nurseries can tell families exactly how the building was washed and disinfected.
10. Tax invoices available for schools, local administrations and companies. See the service page for details.

Before and after spraying

Example case: a child development centre in Song Phi Nong

An illustrative scenario to show the planning, not a verified customer review.

Teacher Oy runs a child development centre in Song Phi Nong district. During the flood the ground floor went under water and upstairs rooms sheltered village families for two weeks; one child there was suspected of pertussis and managed by the hospital.

When the water receded, Teacher Oy and the centre committee drew up a plan before readmitting children. Volunteers shovelled out mud, washed floors, discarded soaked fabric toys, washed plastic ones and aired the rooms for days. Only then was a disinfection team called. Food containers and bottles were stored away, everyone left during spraying, and teachers returned after the specified wait and airing.

Teacher Oy then messaged the parents' LINE group explaining what had been done and asking for three things: check your child's vaccine record; if your child has coughing fits or a long cough, see a doctor and keep them home as advised; and wash your child's hands on arrival every day. This approach cannot guarantee no child will fall ill, but it gives everyone a clear role and lowers the chance of the bacterium spreading in the centre.

Post-flood pertussis prevention checklist

Health

• Check every child's vaccine record. If a dose was missed during the flood, contact a clinic to catch up.
• Pregnant women should ask their doctor about recommended vaccines during antenatal care.
• Anyone with coughing fits, coughing until vomiting, or a cough lasting more than two weeks should see a doctor and keep away from babies.
• A baby with breathing pauses, blue colouring or inability to feed needs hospital care immediately.
• If a doctor diagnoses pertussis, follow their advice on staying home and on care for close contacts.

The building

• Wear boots, rubber gloves and a mask while clearing mud.
• Remove mud, rubbish and items ruined by water.
• Wash floors, walls and furniture with water and detergent, then let them dry.
• Open doors and windows and use fans to move air.
• Then disinfect surfaces, with everyone out during spraying and re-entry at the time the technicians give.

After spraying

• Wipe door handles, rails, tables and toys every day.
• Space children's sleeping spots as far apart as practical.
• Do not share cups, spoons or feeding bottles.
• Teach children to cough into their elbow and wash hands with soap often.
• Anyone coughing should wear a mask around others.

FAQ: whooping cough and post-flood disinfection

Can you catch whooping cough from floodwater?
No. Bordetella pertussis spreads from person to person through cough and sneeze droplets. Flood conditions such as crowding, poor ventilation and missed vaccinations make spread more likely.

If we spray, will we be protected from pertussis?
No. Spraying reduces germs on surfaces at the time of treatment but does not create immunity or stop new droplets from someone who is ill. The main protection is vaccination, supported by separating the sick as a doctor advises, masks, handwashing and ventilation.

Does CHEMGENE really cover the pertussis bacterium?
The product and service information on the WHD website lists Bordetella pertussis among the organisms covered. You can ask WHD directly for the test documentation.

Do we have to leave during spraying?
Yes. Everyone, including children, older people and pets, should leave the sprayed zone and return at the time the technicians give, about 30 minutes after spraying per the service information, after airing the room.

Do we need to clean up the mud before booking?
Yes. Disinfectants work best on clean surfaces, and the CDC advises cleaning before disinfecting.

Is there any residue? Can toys go back in use?
Do not assume there is no residue at all. Ask the technicians how to handle toys that children put in their mouths, food containers and bottles, which should be put away before spraying and washed appropriately.

Get homes, schools and nurseries ready after the flood

Talk to WHD about disinfection spraying after your mud clean-up, especially where babies and young children will return.

See WHD Disinfection Service

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

Related links

• World Health Disinfection spraying service
• CHEMGENE HLD4H disinfectant
• Residential ozone disinfection for musty post-flood air

References

• DDPM flood situation, 2 October 2026, via Bangkok Biz News: bangkokbiznews.com/news/news-update/1254629
• World Health Organization fact sheets: who.int/news-room/fact-sheets
• CDC Floods: cdc.gov/floods
• CDC Whooping Cough (Pertussis): cdc.gov/pertussis
• Department of Disease Control, Thailand: ddc.moph.go.th