Fibres in focus

I believe there is a link between fibre type and the penetration of both heat and disinfectant.

As a former linen services manager at St James’s Hospital in Leeds, an establishment which introduced microfibre theatre fabric into the health service, the hospital also used polyester bedding which was serviced without complaints about malingering bacteria.

Much has been written in Laundry and Cleaning News about two new rules that need to be applied to laundry wash procedures in order to arrest the spread of infection from new strains of bacteria which seem to be resistant to both heat at 71°C and sodium hypochlorite bleach when used as a disinfectant.

Dr Kathy Orr’s article (December 1997) highlighted the problems, but failed to say how the testing was carried out. The question that needs to be asked is: “what part does fibre content play in the retention of bacteria?” The answer to this may have an effect on the problem raised by Ian Hargreaves’ comments in the same issue about the increased cost of laundering hospital linen and the potential reduction in capacity of hospital laundries should it be necessary to increase thermal disinfection temperatures and increased wash process times.

Hospitals use three fibre types which are all capable of being thermally disinfected. The use of heat labile fabrics has been very much reduced with the closure and resettlement of patients from hospitals for the mentally handicapped and the redefining in many hospitals of geriatric beds as acute beds.

  Cotton is still the most common fibre found in hospital linen. The fibre is irregular in shape, with a soft, yet rough skin. In order to make a thread, the fibres a tightly twisted, and are then woven into a dense cloth before being made into bedding of cloth for theatre drapes.

Polyester and polyamide fibres are used either alone or as mixtures with cotton. These fibres are of a regular formation with a hard surface. Staple fibres, they are twisted either with each other or with cotton to form cloth.

Developments have recently produced microfibre cloth for use in theatres. This utilises polyester and polyamide filament fibres that are not twisted but bunched and then woven into cloth. While this type of cloth creates a good barrier to bacteria, it also appears to shed unwanted soiling and bacteria easily.

Most soiling is loose and easily removed by flushing with water. It is only the deeply ingrained soil that requires high temperature and a good mechanical action to remove it. This is more evident on cloth using staple fibres than filament fibre fabrics. The question that needs to be addressed is to what degree fibre type retains bacteria.

When microfibre was introduced as a theatre fabric, much work was done to ensure that the cloth was clean after laundering. Micro- biological tests were carried out after the final wash process was agreed. No evidence of any growth was recorded.

The wash process was, however, shorter than the normal “foul wash”, used for the cleaning of cotton theatre linen, but still incorporated a ten-minute thermal disinfection cycle.

Before any recommendation is made to the Department of Health about revising the guidance given to launderers, the effect of the current guidelines should be proved against the various fabric constructions on offer to hospitals. It could be that the increased cost and wash times with the subsequent reduction in laundry capacity may not be so bad.