Better engineering of hospital handbasins could prevent superbug outbreaks

Handbasins help prevent infections in hospitals but new research from Flinders University warns that contaminated basins in healthcare might put patients at risk and have implications in outbreaks of superbugs.

The Journal of Hospital Infection review compares healthcare handbasin design guidelines across 39 countries with the scientific evidence – leading to calls for better designs to reduce the risk of drug-resistant bacteria occurring, for example the commonly difficult-to-treat Carbapenemase-producing Enterobacterales (CPE).

The study found substantial inconsistencies between international healthcare design guidelines, while the limited evidence available makes it difficult to determine which design features best reduce the risk of pathogen spread, says lead author Mikaela Todarello, a PhD candidate in Environmental Health at Flinders University.

Handbasins need to support effective handwashing without creating avoidable opportunities for pathogens to spread.

Microbes can build up in taps and drains. When water hits contaminated surfaces, splashing can carry them onto nearby equipment and surfaces.

There is evidence that handbasin design influences how microbes spread, which means we have a real opportunity to improve these designs and reduce the risk to patients."

Mikaela Todarello, PhD candidate in Environmental Health, Flinders University

The review identified several features that deserve closer attention:

FLAT BASIN surfaces can allow water to pool and may produce more splashing than curved surfaces, creating conditions that favour microbial growth and spread.

SHALLOW BASINS have been associated with greater dispersal of small airborne droplets, known as bioaerosols, beyond the basin than deep bowls.

DRAIN POSITION matters. When drain sits directly beneath the tap, the water stream can strike it and generate droplets and aerosols, particularly if higher pressure. Positioning the drain away from the water stream can reduce splashing.

WATER FLOW and bowl slope can change splash behaviour. How a basin is positioned and used, and whether water pools in it, also need to be considered. 

"There is still limited research examining how these features work together during everyday use, or which combinations best reduce infection risk," adds Ms Todarello, from the College of Science and Engineering.

"We need to close that gap so future design guidelines are based on strong evidence from real healthcare environments."

Professor Harriet Whiley, Professor in Environmental Health at Flinders University, says the findings point to a practical opportunity to strengthen infection prevention.

"We ask healthcare workers to wash their hands to protect patients. We should make sure the handbasins they use are designed with the same goal in mind," says Professor Whiley.

"Better engineering could reduce splashing, limit biofilm buildup and prevent contamination from spreading. We can do better, particularly in areas caring for patients who are most vulnerable to infection."