Water is a ward too

Draft for Małgorzata’s review before publication · based on published research

Most hospital staff think of water as a utility. It comes out of the tap, it is clean, it is someone else’s problem. For a hospital hygiene team, water is closer to a ward of its own: it has residents, it has risk, and it needs regular rounds.

From reacting to looking ahead

The classic model is reactive. A sample is taken, a laboratory reports, and a result arrives on someone’s desk. What happens next depends on who reads it. With colleagues in our hospital hygiene unit, we built something different: a proactive surveillance system for water, food and environmental surfaces, with a planned phase before sampling and a structured phase after the result.

Over five years the system handled 1,470 samples and produced 539 reports. It covered routine checks after scheduled surveys and compliance checks, such as the verification that happens before a new ward opens.

A result is only useful if it changes what someone does tomorrow morning.

What the numbers showed

For Legionella risk in water we saw statistically significant trends across samples and reports. Throughout the period, the prevalence of healthcare-associated infections in the hospital stayed below 5%. That figure does not prove cause and effect, but it tells you the system was working in a hospital that kept its infections under control.

Speed matters too

In an earlier study, we compared the standard culture method with real-time PCR on 77 water samples from hospital wards. PCR showed high sensitivity and a high negative predictive value. In practice, that makes it a fast screening tool to rule out Legionella pneumophila, so culture capacity can go where it is needed.

What I tell hospital teams

• Plan sampling around risk, not around the calendar.
• Agree in advance who acts on each type of result, and how fast.
• Use rapid methods to exclude risk quickly; use culture to confirm.
• Treat every new or renovated ward as a water system that must be checked before patients arrive.

The EU Drinking Water Directive now asks hospitals to take water-system risk seriously. The hospitals that will find it easiest are the ones already doing rounds on their water.