New early warning system for catheter infections

Urinary catheters are the most commonly used medical devices, with hundreds of millions sold worldwide every year. Many of these will be used for long-term management of incontinence in older individuals or those with spinal cord injuries, and these patients are at particular risk of infection, and associated complications.

One of the most serious complications of infection is the encrustation and blockage of catheters, which is mostly caused by a bacterial species called Proteus mirabilis. Blockage, in turn, leads to the onset of serious complications such as kidney infection and septicaemia, one of the UK’s biggest killers.

A reliable system for patients or their carers to spot infection early and take action before blockage occurs would have considerable benefits to patients, and could considerably reduce NHS costs.

The catheter on the right shows the warning system in use

Leading the university’s research is Dr Brian Jones, Reader in Molecular and Medical Microbiology at the university’s College of Life, Health and Physical Sciences, and Head of Research Development at the Queen Victoria Hospital, East Grinstead. This work is a collaboration with scientists at the University of Bath.

Dr Jones said: “Catheter blockage and encrustation is a real problem for many patients, and unfortunately is often only detected when more serious and life threatening complications arise, and patients require hospital treatment.”

He explained how the early warning system works: “With colleagues at the University of Bath, we have developed a chemical coating that can be applied to the catheter surface. This coating releases a bright green dye when the urine becomes alkaline due to Proteus infection. The dye then accumulates in the urine collection bag providing a simple, visible, early warning that catheter blockage may be imminent.

“The prototype system gives a 12-hour advanced warning of catheter blockage when tested in our laboratory models of catheter infection, but a focus of further work will be understanding how this coating will perform in under a wider range of conditions we expect to encounter during use in patients.”

He added: “We have a long way to go with this work but our results so far are very encouraging. If successful, the system could save lives and save the NHS money, which really motivates us to keep innovating in this area to address these unmet clinical needs.”