Reducing the risk of iatrogenic Creutzfeldt–Jakob disease by improving the cleaning of neurosurgical instruments

Abstract

In all, there have been 178 variant Creutzfeldt-Jakob disease (vCJD) patients diagnosed in the UK, with an estimated maximum 1:2000 carriage rate based on archived appendix and tonsil tissue, implying that infection may be rare but carriage relatively frequent. Previous workers have identified that maintenance of surgical instruments in a humid atmosphere after use and prior to cleaning assists cleaning efficacy. Recently the Department of Health/Advisory Committee on Dangerous Pathogens UK have recommended a surgical instrument cleanliness threshold post cleaning of <5μg protein per instrument side. To quantify cleanliness of neurosurgical instruments and to investigate cost-effective measures for improved cleaning. Two instrument protein quantification methods were used: one based on the International Standard (15883 series) using sodium dodecyl sulphate elution and ortho-phthalaldehyde reaction, and a second in-situ protein fluorescence detection system (ProReveal) providing results per instrument side. In-vitro investigation of the efficacy of some commercial and in-house pre-clean wetting agents was undertaken using artificial test soil and stainless steel discs under standard conditions. In-vivo evaluation of best-performing in-vitro agents was undertaken on craniotomy sets. ProReveal technology demonstrated that 163 out of 187 (87%) neurosurgical instruments had <5μg residual protein per instrument side. The use of proprietary National Health Service plastic bags and sterile water-soaked wound pads were equivalent in efficacy to commercial pre-cleaning wetting products and significantly less expensive. Although we demonstrate low in-situ protein levels on neurosurgical instruments and the beneficial effects of keeping instruments moist, other cleaning critical-control points such as instrument loading patterns should also be monitored.