The 2026 Floods and Facilities That Must Reopen First

According to Thailand's Department of Disaster Prevention and Mitigation, in a 06:00 update on 5 October 2026 reported by Daily News, floods affected 26 provinces plus Bangkok and 1,270,151 households. Across an area that large, many shophouse clinics, pharmacies, dental practices and small health facilities will have had their ground floors flooded.

The difference between a home and a clinic is who walks in. Clinic visitors are often already unwell: older adults with chronic disease, diabetics coming for wound dressing, feverish children, pregnant women and people with weakened immunity. A germ that causes minor trouble in a healthy adult can be serious for them. WHO and CDC therefore give specific guidance on restoring health facilities after floods, covering water systems, air conditioning, moldy materials, flood-exposed supplies and surface cleaning and disinfection.

Important: disinfection spraying is one step in recovery. It does not replace a facility's infection prevention and control protocols, the sterilisation of medical instruments, engineering checks of water systems or regulatory requirements. Facilities should follow Ministry of Public Health guidance and their own infection control committee first.

Example Case: A Shophouse Clinic Deciding When to Reopen

Note: this is an illustrative scenario built from common post-flood situations, not the story of a specific clinic or person.

Dr. A runs a small medical clinic in a two-unit shophouse in a district town. Downstairs are the waiting room, consultation room, dressing room and medicine store; the family lives upstairs. When the river backed up into the market, murky water mixed with drain water flowed into the clinic and stayed for several days. Dr. A and the nurse carried some medicines upstairs in time, but the examination bed, gauze cabinet, waiting-room chairs, the lower air conditioner and the bottom of the gypsum walls all went under.

Once the water dropped, regular patients started calling. An older woman with diabetes needed her foot wound dressed every two days. Several children nearby had fever and cough. Many people who had waded through water wanted a check-up. Dr. A knew the community needed the clinic, but also that a dressing room just soaked in sewage-tainted water should not be used straight away. Black spots were appearing on the gypsum, the handwashing sink drain smelled and the air conditioner gave off a musty odour.

Dr. A asked three questions. Which germs put our patients most at risk if we reopen too early? What must be thrown away and what can be cleaned? And once cleaning and repairs are done, who can disinfect every surface in the clinic to one standard in limited time? The ranking below answers the first; the rest of the article answers the others.

How We Ranked Flood Germs for Clinics and Health Facilities

This is WHD's editorial ranking. It is not official, not based on any infection statistics and not medical advice. Our criteria:

1. Relevance to post-flood health facility guidance from WHO, CDC and the Department of Disease Control, such as water systems, mold and surface cleaning.
2. Vulnerability of the people exposed, including immunocompromised patients, patients with wounds, older adults and young children.
3. Ability to persist in water, damp and plumbing, described qualitatively without unsourced figures.
4. Severity of infection in typical clinic patients.
5. Ease of spread via hands, surfaces, equipment or waiting-room droplets.

Germs lower on the list still matter; they are simply more relevant to certain facility types, such as paediatric clinics or buildings with ground-floor storerooms.

No. 1: Pseudomonas aeruginosa, the Water-Loving Germ in Sinks and Drains

Why it ranks first: Pseudomonas thrives in water and on wet surfaces and has long been associated with healthcare infections. After a flood, drains, handwashing sinks and damp corners become ideal habitats, and the germ is often resistant to several antibiotics. It is the first germ to think about before reopening a dressing room.

Where it hides: sink drains, taps, patient showers, buckets, damp mops and equipment that was submerged.

Who is at risk: patients with burns, diabetic ulcers or surgical wounds, catheterised patients and the severely ill or immunocompromised.

Prevention: discard flood-exposed dressing supplies, scrub sinks and drains, flush the plumbing as advised by a plumber, keep clean equipment away from sinks and use laundered, dried mops.

Cleaning and spraying: after scrubbing, spraying reduces bacteria across hard surfaces in dressing and consultation rooms. Pseudomonas belongs to the bacteria group CHEMGENE HLD4H product information says it covers, but WHD makes no organism-specific claim; facilities can request test documents. Inside pipes, flushing and engineering checks are what count.

No. 2: Aspergillus and Mold in Walls, Ceilings and Air Conditioning

Why it ranks second: for most people mold means allergies, but for patients on chemotherapy, transplant recipients or anyone with very low immunity, Aspergillus spores can cause serious lung infection. Post-flood facility guidance therefore stresses removing moldy materials and controlling dust during repairs.

Where it hides: gypsum, ceiling boards, insulation, carpets, bed curtains, waiting-room upholstery, air-conditioner filters and drip trays, and cardboard boxes in storerooms. CDC generally advises cleaning and drying within roughly 24 to 48 hours to limit growth.

Who is at risk: people with asthma or allergies and, most seriously, the severely immunocompromised.

Prevention: remove wet porous materials, seal repair zones with plastic sheeting, clean or replace AC filters, keep vulnerable patients away from repair work and dehumidify until dry.

Cleaning and spraying: after removal and scrubbing, spraying reduces mold left on hard surfaces. The product states it covers fungi as a group, not Aspergillus specifically, and spraying never replaces tear-out. If mustiness remains once dry, ozone disinfection for buildings can be a complementary step.

No. 3: Legionella pneumophila in Water Left Standing During Closure

Why it ranks third: when a clinic is closed for days, water sits in pipes, tanks, heaters and showerheads. CDC notes that stagnant water in building plumbing favours Legionella growth, and inhaling contaminated water droplets can cause a type of pneumonia.

Where it hides: storage tanks, water heaters, showerheads, unused taps, cooling towers in larger buildings and nebulisers filled with unsuitable water.

Who is at risk: older adults, smokers, people with chronic lung disease and the immunocompromised.

Prevention: have a plumber or engineer inspect and flush the system, clean tanks and follow a building water management program as CDC recommends; use sterile water in nebulisers.

Cleaning and spraying: to be direct, surface spraying does not fix Legionella in plumbing. That requires water management. Spraying helps only with surfaces around sinks and bathrooms after cleaning. Legionella belongs to the bacteria group the product says it covers, with no specific claim.

No. 4: E. coli and Klebsiella pneumoniae, Gut Bacteria from Sewage

Why it ranks fourth: floodwater that flows through markets and drains often carries sewage, coating clinic surfaces with gut bacteria such as E. coli and Klebsiella. Some strains of this family are drug-resistant and are a known problem in healthcare, so they should not be left on surfaces patients touch.

Where it hides: waiting-room floors, patient toilets, examination bed legs, door edges, wheelchair wheels and mud in corners.

Who is at risk: older adults, catheterised patients and anyone with open wounds; infections range from diarrhoea and urinary infection to wound and bloodstream infection in frail patients.

Prevention: remove all mud, wash floors and lower walls, discard flood-exposed supplies and linen, and keep strict hand hygiene before and after patient contact.

Cleaning and spraying: spraying after cleaning reaches every surface, including spots wiping misses. Both belong to the bacteria group the product says it covers, without specific claims. Salmonella, another faecal germ, is named directly in the product information.

No. 5: Staphylococcus aureus, Including MRSA, on Shared Touch Points

Why it ranks fifth: Staphylococcus aureus is a common cause of skin and wound infections, and methicillin-resistant strains (MRSA) are well known in healthcare. After floods, more patients arrive with wounds from wading and debris, so shared touch points must be clean.

Where it hides: examination beds, rails, counter pens, blood pressure cuffs, door handles and staff phones.

Who is at risk: diabetics, dialysis patients and older adults, who face more severe infections.

Prevention: hand hygiene before and after every patient, scheduled wiping of touch points, disposable bed covers and separate dressing sets per patient.

Cleaning and spraying: whole-area spraying after cleaning resets every touch point at once before reopening. It belongs to the bacteria group covered, with no MRSA-specific claim here; routine cleaning must continue afterwards.

No. 6: Norovirus in Patient Toilets and Waiting Rooms

Why it ranks sixth: after floods, more patients arrive with vomiting and diarrhoea. Norovirus spreads very easily via hands, surfaces and vomit droplets and holds up well on surfaces, so patient toilets and waiting rooms can become hotspots.

Where it hides: toilets, taps, soap dispensers, waiting chairs, bins and any surface where vomit landed.

Who is at risk: older adults and young children, who dehydrate quickly.

Prevention: soap and water handwashing, since norovirus resists alcohol gel better than many germs; immediate cleanup of vomit with gloves and mask; a separate toilet for diarrhoea patients where possible.

Cleaning and spraying: norovirus is named directly in the CHEMGENE HLD4H product information, so spraying toilets and waiting rooms after cleaning is well targeted, with no patients or staff in the zone during application.

No. 7: Respiratory Viruses: Influenza H1N1, SARS-CoV-2 and RSV

Why it ranks seventh: after floods, people crowd into shelters, are exhausted and arrive at clinics with fever and cough. Packed waiting rooms let respiratory viruses spread, even though these viruses do not come from floodwater.

Where it hides: droplets in the waiting area, counters, pens, thermometers, chairs and rails.

Who is at risk: young children, older adults, pregnant women and people with chronic illness.

Prevention: a separate screening point for fever and cough, masks, ventilation, spaced seating and frequent touch-point cleaning.

Cleaning and spraying: this is the group WHD's service and product information names most clearly: SARS-CoV-2, RSV, influenza H1N1 and H5N1. Spraying waiting and consultation rooms after cleaning targets them directly.

No. 8: Nontuberculous Mycobacteria in Plumbing and Dental Unit Waterlines

Why it ranks eighth: these mycobacteria live in water and soil, form biofilm in pipes and are linked to skin infections after some procedures, which is why dental unit waterlines need special care. Days of closure after a flood leave water standing in those lines.

Where it hides: dental unit waterlines, instrument water bottles, unused pipes and humidifiers.

Who is at risk: people with chronic lung disease and the immunocompromised; skin infections can be slow to appear and slow to heal.

Prevention: follow the dental unit manufacturer's waterline cleaning and maintenance instructions, flush systems before reopening and monitor water quality per professional guidance.

Cleaning and spraying: CHEMGENE HLD4H product information lists mycobacteria, but not individual nontuberculous species. Spraying helps with dental room surfaces after cleaning; waterlines must be handled per manufacturer instructions.

No. 9: Enteroviruses Behind Hand, Foot and Mouth Disease in Paediatric Clinics

Why it ranks ninth: the rainy season is a common time for hand, foot and mouth disease in young children. With childcare centres closed and children gathered in shelters, paediatric clinics may see more cases. The virus spreads via saliva, blister fluid and stool.

Where it hides: waiting-room toys, seat cushions, changing tables, cot rails and baby scales.

Who is at risk: young children. A drowsy child, frequent vomiting or any neurological sign needs urgent medical attention.

Prevention: remove hard-to-clean toys, separate waiting space for children with fever and rash, handwashing after nappy changes and wiping scales after each use.

Cleaning and spraying: hand, foot and mouth virus is named in WHD's service information, so spraying children's waiting and examination areas after cleaning is directly relevant.

No. 10: Leptospira from Rats in Ground-Floor Storerooms

Why it ranks tenth: for patients inside the clinic, this risk is lower than the others. For staff clearing storerooms, plant rooms or basement car parks it is real, because rats escaping the water shelter in buildings and leave urine on floors.

Where it hides: storerooms, file rooms, under shelving, car parks and standing water around the building.

Who is at risk: staff with wounds who wade or clean these areas.

Prevention: boots and rubber gloves, covered wounds, rodent control and a doctor visit for fever after water contact.

Cleaning and spraying: after washing storerooms and areas with rodent signs, spraying reduces bacteria on surfaces. Leptospira belongs to the bacteria group covered, with no specific claim.

What the Ranking of Flood Germs in Clinics Tells Us

The ten fall into three groups. Water-system germs (Pseudomonas, Legionella, mycobacteria) are managed mainly by flushing and water management. Material and airborne germs (mold) need tear-out, drying and dust control. Surface and touch-point germs (gut bacteria, Staphylococcus, norovirus, respiratory viruses, enteroviruses, Leptospira) are where spraying after cleaning helps most, while also supporting the other two groups on surrounding surfaces.

Why Ordinary Wiping Is Not Enough for a Flooded Health Facility

• Large areas with many crevices: bed legs, under counters, behind medicine cabinets and along skirting are easily missed by a small team.
• Staff are caring for patients at the same time: disinfecting a whole flooded clinic is far bigger than a routine cleaning round.
• Bleach has limits: it must be diluted correctly, used on already clean surfaces and can corrode metal and some equipment.
• Uneven standards: different people, days and products make it hard to be sure every room went through the same process.
• Documentation: facilities often need records of how areas were restored; a provider that issues tax invoices and job details helps.

WHO and CDC give the same principle: clean first, then disinfect. In a health facility, disinfection should cover the whole area in one round before patients return.

WHD Post-Flood Disinfection Spraying for Clinics and Health Facilities

WHD's disinfection spraying service uses trained technicians who spray and ULV-fog (Ultra Low Volume fine mist). According to the service information, the disinfectant is CHEMGENE HLD4H, a medical-grade UK product containing Benzalkonium Chloride and Didecyldimethylammonium Chloride, described as broad-spectrum against viruses, bacteria and fungi. Named organisms include SARS-CoV-2, RSV, influenza H1N1 and H5N1, hand, foot and mouth virus, norovirus, mycobacteria, Salmonella and mold, with a stated 99.99% efficacy.

The service page lists approvals or endorsements from Thailand's Department of Medical Sciences, Mahidol University, NHS England and EN 14476:2013+A2:2019, and its customers include hospitals, schools, malls, airports, offices, airlines, banks and residential buildings. Facilities can request test documents for specific organisms; for anything not on the list, we claim nothing beyond the data.

The process in a flooded clinic

1. Joint survey with the person in charge: water height, duration, high-risk rooms such as dressing, procedure and dental rooms and patient toilets, and equipment that must not be sprayed.
2. Mud removal, disposal and washing first: spraying follows mud removal, tear-out of damaged materials, disposal of flood-exposed supplies and surface washing.
3. Zoning and preparation: sensitive equipment covered or moved, medicines stored in closed cabinets, patients and staff out of each zone.
4. Spraying: floors, lower walls, counters, waiting chairs, toilets, rails, doors and touch points, with ULV mist in rooms full of corners.
5. Re-entry: the service information says about 30 minutes before normal use; always follow the time technicians give on site and ventilate before patients arrive.

We do not claim spraying leaves no residue. Patient-contact and medicine-preparation surfaces should be wiped as advised and per facility protocol. This service is not sterilisation of medical instruments, which must follow professional standards.

10 Reasons Clinics Choose Disinfection Spraying Before Reopening

1. Your patients are more vulnerable than the general public.
2. The whole clinic is done in one round, without pulling staff away from patients.
3. ULV mist reaches crevices like bed legs and under counters.
4. A medical-grade product described as broad-spectrum. See the service
5. Clearly named organisms include the respiratory viruses, norovirus and hand, foot and mouth virus common in waiting rooms.
6. Quick turnaround: about 30 minutes before normal use, per the service information.
7. Experience with hospitals, which are listed among WHD's customers.
8. Tax invoices for accounts and insurance claims.
9. Free supplies: the current promotion includes a CHEMGENE spray and WELLGIENIC wet tissues for daily touch-point wiping.
10. Confidence for regular patients that the clinic was cleaned and disinfected. Book a spraying team

Before and After Spraying

Example Case: Three Days Before Dr. A Reopens

Illustrative scenario to explain the process, not a customer review.

Day one: moldy gypsum removed, flood-exposed gauze, cotton and medicines discarded, floors and counters washed, AC filters cleaned and dehumidifiers run overnight. Day two: a plumber flushed the pipes, cleaned the tank and checked the patient bathroom heater, while reusable instruments went through the clinic's normal cleaning and sterilisation. Day three: the spraying team surveyed with the head nurse, split the clinic into four zones, covered sensitive equipment, cleared each zone of people, sprayed and gave a re-entry time. The next morning the clinic reopened with a separate fever screening point, and the patient with diabetes had her wound dressed in a room that had been repaired, cleaned and disinfected.

Clinic Recovery Checklist

• Safety: electrician checks power; photograph damage for insurance; notify regulators as required.
• Discard: flood-exposed medicines, supplies, sterile packs and wet porous materials; have exposed medical devices assessed.
• Water and air: flush pipes, clean tanks, maintain dental waterlines, clean AC filters, dehumidify.
• Clean then disinfect: scrub everything, book spraying, re-enter on time, ventilate, wipe medicine-prep surfaces.
• After reopening: screen fever, cough and rash; clean touch points routinely; report returning mold or odour.

FAQ: Flood Germs in Clinics and Disinfection Spraying

Does this ranking replace infection control guidance? No. It is WHD's editorial ranking; follow Ministry of Public Health guidance and your infection control committee.

Can spraying replace instrument sterilisation? No. It treats building surfaces only.

Can spraying deal with Legionella in pipes? No. That needs flushing, tank cleaning and water management.

How long must the clinic close? About 30 minutes per the service information, depending on size and zones; follow the technicians' time.

Can pharmacies and dental clinics book? Yes, with tax invoices.

Can I see test documents? Yes. Call 065-556-6294 or LINE @whd268.

Clinic Cleaned and Repaired? Let WHD Disinfect Before Patients Return.

Book Clinic Disinfection Spraying

Call 065-556-6294 · LINE @whd268

Related Services and References

• WHD disinfection spraying service
• Ozone disinfection for buildings
• Daily News, DDPM flood update 06:00, 5 Oct 2026: read the source
• WHO fact sheets: read the source
• CDC, Floods: read the source
• CDC, Legionella: read the source
• Department of Disease Control, Thailand: read the source