When parents start counting how many of their neighbours' children are ill

A 1,240-Pupil Primary School With 23 Dengue Cases in One Term — and the Parents' Meeting Nobody Wanted

Why waiting for the municipality to fog is too slow, and why a school should be able to fog for itself

A school is where 1,240 children spend eight hours a day, five days a week. If infected Aedes are present on the grounds, the disease does not spread one child at a time. It spreads a classroom at a time.

What it actually costs

Aedes bite during the day, exactly when children are at school

Aedes aegypti feed during daylight, especially morning and late afternoon — precisely the school day, unlike night-feeding species. That makes a school one of the highest-risk transmission settings there is.

Parents count faster than the school can

The school only knows about absences reported with a medical certificate. Parents compare notes in class LINE groups and have a figure within two days, which leaves the school permanently on the back foot.

The three questions that are hardest to answer

When did you last fog, how often do you fog, and what measures do you have? None of those can be answered well if the school owns no machine and waits for an outside agency.

The impact on learning and on parents' decisions

Affected pupils missed 7 to 12 school days each, disrupting continuity of learning — and the following year three families moved their children, citing health safety directly.

Why the usual fixes do not work

Waiting for the municipality to fog on its rounds

Local authorities cover very large areas on limited schedules. Most schools are fogged once or twice a term, which is many times longer than the 7 to 10 day Aedes life cycle.

Asking pupils to apply repellent from home

Helpful at the individual level and worth encouraging, but in practice many children forget or apply it unevenly, and repellent wears off within a few hours — so it does not cover a full school day.

Fitting insect screens to classroom windows

It reduces mosquitoes indoors and is worth doing, but Thai schooling involves a great deal of outdoor activity — PE, scouts, the botanical garden and break times — which is when most bites happen.

Burning coils or using aerosols in classrooms

Not appropriate in a setting with large numbers of children, both for safety and for repeated daily exposure — and it does nothing about the outdoor areas where transmission actually occurs.

Larval survey and clean-up alone

An excellent activity that should continue, but it only cuts future cycles. It does not kill the infected adults already flying on the grounds this week.

If Aedes fly only 50 to 100 metres, the problem is inside the school fence

The fact that changed Director Suchat's thinking most was that Aedes aegypti fly only 50 to 100 metres from where they emerge.

That means when cases cluster in one building, the breeding and resting sites are almost certainly within that radius — which is inside the school fence, and entirely within the school's own authority to manage.

Once the problem area is inside your own fence, waiting for an outside agency once or twice a term stops making sense, because the school has the ground, the staff and control of its own timetable.

The AIROFOG AT35 suits schools particularly well. It is a light, shoulder-carried machine that caretakers can genuinely operate. Its 100 percent stainless steel body resists corrosion, giving the long service life a capital asset needs. It runs both water-based and oil-based chemicals, is certified in Germany and the UK, conforms to the standard equipment schedule — which keeps subsidy-funded procurement correct — and is backed by a service centre with genuine parts in Thailand.

1. The school fogs on the interval that actually works

The Aedes life cycle is 7 to 10 days, while waiting for an outside agency means once or twice a term. Owning a machine lets the school fog weekly, on an interval that genuinely breaks the cycle.

2. Fog on Friday evening, ventilate all weekend

Owning the machine means choosing your own timing. Fogging after school on Friday leaves two full days of ventilation before pupils return — impossible when you fog on somebody else's schedule.

3. Fog reaches boundaries, under buildings and still corners

Adult Aedes rest in shrubs, under buildings, along boundaries, around ponds and in wind-free corners that coarse spray cannot reach. Very fine thermal fog drifts into all of them.

4. Light enough for caretakers to use in practice

Equipment that is hard to use ends up in the store room. The AT35 is a light shoulder-carried machine designed to be simple, so school staff genuinely use it every week.

5. 100 percent stainless steel body means a long asset life

For equipment that has to stay with the school for years and pass between administrations, durability decides everything. An all-stainless body resists the chemical corrosion that is the leading cause of failure.

6. Conforms to the standard equipment schedule

Procurement from subsidy or resource-mobilisation funds must follow procurement regulations. Choosing a machine on the standard schedule, with certification, keeps purchase and acceptance straightforward.

7. Runs both water-based and oil-based chemicals

The school can follow local public health guidance on product and formulation without buying two machines, and without risking damage from the wrong product type.

8. Useful for disinfection on campus as well

Beyond mosquitoes, the machine disinfects the canteen, toilets, sick room and common areas during other outbreaks — so one asset serves several missions.

9. A concrete answer at the parents' meeting

When parents ask what measures are in place, saying the school owns a fogger and fogs every Friday evening with a written record is entirely different from saying you wait for the municipality.

10. Service centre and genuine parts inside Thailand

Equipment that cannot be repaired becomes a liability on the asset register. A local service centre with genuine parts and technicians of over 10 years' experience keeps it working for years.

The three-step process

1. Survey the campus for risk points inside the fence

Look for breeding and resting sites within 100 metres of the school buildings: planter saucers, old tyres, uncovered water butts, blocked gutters, boundary planting, under-building spaces and pond surrounds.

2. Set a fogging schedule around the timetable

Fog on Friday evening after school so the whole weekend is available for ventilation. Ask teachers and caretakers to close classroom windows and put away teaching materials beforehand.

3. Fog, record, and run larval control alongside

Fog the planned route, flush and clean the machine after every use, record the date and area as evidence, and run the pupil-led larval survey every week alongside it.

From someone who uses one

When a parent asked when the school had last fogged, I said two months ago — and the mood in that room changed instantly. I knew that answer was unacceptable. Once we had our own machine and fogged every Friday evening, the following term produced just two cases. And now I can answer parents with a schedule and a record instead of an excuse.

Director Suchat M. — principal, 1,240-pupil primary school, Nakhon Pathom

Frequently asked questions

When is it safe to fog at a school?

Fog on Friday evening after school, or during school holidays, so there is at least one to two days of ventilation before pupils return. Close classroom windows and put away teaching materials before every round.

How often should we fog?

Weekly through the rainy season, so the interval is shorter than the 7 to 10 day Aedes life cycle. Fortnightly is usually enough in the dry season, and you should add rounds immediately if a pupil case is reported.

Can caretakers operate the machine themselves?

Yes. The AT35 is a straightforward shoulder-carried machine, and WHD provides operating, chemical mixing and protective equipment training on delivery.

Can it be bought with subsidy funds?

Yes. The machine conforms to the standard equipment schedule and comes with certification documents for procurement. Our team can supply them to your procurement officer from the price enquiry stage.

Does it replace larval control?

No — the two go together. Fogging kills infected adults already flying, while the larval survey cuts future cycles. Both are needed for real control.

Can it also be used to disinfect the canteen and toilets?

Yes. A thermal fogger can be used for disinfection of common areas — canteen, toilets, sick room and classrooms — during other outbreaks, using the appropriate product.

How many machines does a school need?

A medium to large school on up to 20 rai is usually served by one machine. Very large campuses or several separated buildings may need two. We assess this from your site plan.

How do we order or get a quotation?

Call 065-556-6294 or add LINE @whd268. Our team can advise on specification, prepare a quotation for your school board, and supply certification documents.

Aedes fly only a hundred metres — which means this is within the school's own power to fix

If dengue cases among your pupils are clustering in one building, the source is almost certainly inside the school fence — ground the school can manage itself without waiting for anyone.

The AIROFOG AT35 thermal fogger is a light shoulder-carried machine caretakers can genuinely operate, with a 100 percent stainless steel body, running both water-based and oil-based chemicals, certified in Germany and the UK, conforming to the standard equipment schedule, and backed by a service centre with genuine parts in Thailand.

The WHD team can prepare a quotation and procurement documents for schools. Call 065-556-6294 or add LINE @whd268.

Thermal foggers and ULV sprayers for schools, colleges, municipalities, local authorities, hospitals, factories and private business across Thailand

See the machine and pricing — click here

Call 065-556-6294 or add LINE @whd268