Gut defence and parasites

The parent page opens with straight talk and it is correct throughout: prevention beats every cleanse, plants alone are unreliable against real parasites, and stocking mebendazole is the single most effective line in the module. This page is about the far more likely gut emergency, which the parent does not cover because it is not a parasite at all.

The gut problem you will actually meet

It is a vomiting and diarrhoea bug, it goes through the whole household in about three days, and in a crisis it is genuinely dangerous.

Not because the illness is severe in a healthy adult. It is unpleasant and self-limiting. It is dangerous because of what it does to a household that is already short of water, already using a bucket toilet, already cold, and possibly already caring for somebody vulnerable.

So the sanitation chapter is the gut chapter. Hand washing, covering waste, keeping the toilet area away from food, and having enough water are what stop this, and they stop it far more reliably than anything in a cupboard.

Why the hand gel does not work

This is the specific and widely-missed fact worth taking from this page.

Alcohol hand gel is poorly effective against norovirus, the commonest cause of the winter vomiting bug. It is excellent against many other things, which is why people trust it, and it is close to useless against this one.

What does work:

• Soap and water, properly and for long enough. Physically removing the virus rather than trying to kill it. This is the whole of hand hygiene here.
• A chlorine-based disinfectant on surfaces, at a genuine disinfection strength, on anything the ill person touched: door handles, taps, the toilet, light switches, the kettle.
• Not sharing towels. Give the ill person their own, and a separate hand towel by the sink.
• Careful handling of vomit. It aerosolises, and that is a major route of spread. Ventilate the room, clean it with a chlorine product rather than a spray-and-wipe, and dispose of the cloths rather than rinsing them.

Rehydration is the whole treatment

There is no treatment for the bug itself. There is only replacing what is lost, and that is what decides how it goes.

The parent page points at the medical chapter for oral rehydration salts, and this deserves stating here because it is the highest-value item in the whole module.

• Small sips, continuously, beats a glass every hour. A stomach that has just been sick will reject volume and accept teaspoons.
• Keep going after vomiting. Wait ten minutes, then start again with a teaspoon. Most of it stays down.
• Sachets are ideal, cheap, weigh nothing and store for years. Stock them per person.
• The home version, if you have none: six level teaspoons of sugar and half a level teaspoon of salt in one litre of clean water. Measure it properly, because too much salt is harmful, particularly in a child.
• Plain water alone is not as good, because what is being lost is salt and sugar as well as fluid.
• Watch the output. Pale and regular urine means it is working. Dark, scanty or absent means it is not.

Children and older people are the ones this kills, and they are the ones least likely to ask. Offer, actively, every few minutes, rather than waiting to be told they are thirsty. See oral rehydration.

When not to reach for loperamide

The parent page's kit list on the medical chapter includes loperamide, which is a reasonable thing to hold and a bad reflex to have.

The signs that mean this needs real care, from the parent module's own rule 5: bloody diarrhoea, fever, diarrhoea lasting more than a few days, signs of dehydration that are not improving with rehydration, or any of it in a baby, an older person or somebody already unwell.

The one parasite chlorine does not touch

A point where the water chapter and this one meet, and neither says it alone.

Chlorination at normal household disinfection levels does not reliably kill giardia or cryptosporidium. They are protozoan cysts with a tough wall, and they are the classic thing people pick up from clear-looking streams, exactly as the parent page warns.

So the bleach dose that makes water microbiologically safe from bacteria and viruses is not the whole answer for surface water. What deals with them is:

• Boiling, which handles everything.
• A filter of appropriate pore size, which is what the squeeze filters on the water page are for.
• Both, for anything from a pond, a ditch or floodwater, which is the parent water page's own rule: filter, then disinfect.

This is the reason the water chapter says filter then disinfect rather than one or the other, and this page is where the consequence of skipping it turns up. Giardia is a fortnight of foul-smelling diarrhoea in a household that cannot afford one.