Effect of hand hygiene and glove use on cleanliness of reusable surgical instruments

Analysis of microbial contamination during use and reprocessing of surgical instruments and sterile packaging systems

A surgical site infection (SSI) is one of the most common surgical complications. This study analyzed different sources of microorganisms in the air, on reusable surgical instruments, and the outer surface of sterile packaging systems during the use and reprocessing of sterile goods (from the operating room (OR) to the Central Sterile Supply Department (CSSD)). The microbial load in the air was analyzed via active air sampling and settle plates. Furthermore, the airborne particle load was measured by a particle counter. Contact agar plates were used to determine the microbial load on surgical instruments and sterile packaging systems. The highest average microbial and particle load was measured in the air of the OR (active air sampling: max. 56 CFU/m3; settle plates: max. 9 CFU; ≥0.3 μm particles in size: 1,958,403 no./m3). However, no microbial load (0 CFU) was detected on surgical instruments sampled in the OR. The outer surface of stored sterile packaging systems showed a maximal microbial load of 64 CFU. The most common identified pathogen was coagulase-negative staphylococci. Compared to properly reprocessed reusable surgical instruments and sterile packaging systems, the air still seems to be the primary potential source of microbial contamination, especially within the OR.

Comparison of the disinfecting effect of sodium hypochlorite aqueous solution and surfactant on hospital kitchen hygiene using adenosine triphosphate swab testing

The Japanese Ministry of Health requires large-scale cooking facilities to use sodium hypochlorite aqueous solution (HYP) on food preparation tools, equipment, and facilities to prevent secondary contamination. This study aimed to compare the disinfecting effect of HYP and surfactant using adenosine triphosphate (ATP) swab testing on large-scale equipment and facilities that could not be disassembled and disinfected in hospital kitchen. From May 2018 to July 2018, ATP swab tests were performed on the following six locations in the Shizuoka Cancer Centre Dietary Department Kitchen: cooking counter, mobile cooking counter, refrigerator handle, conveyor belt, tap handle, and sink. Six relative light unit (RLU) measurements were taken from each location. The log₁₀ values of the RLU measurements were evaluated by dividing the samples into two groups: the control group (surfactant followed by HYP swabbing) and the HYP group (HYP swabbing only). The results showed that the RLUs (log₁₀ values) in both the groups improved after disinfection (p<0.05), except for the RLUs (log₁₀ values) of the mobile cooking counter, tap handle, and sink in the control group after the HYP swab. The changes in the RLU (log₁₀ value) did not differ between the two groups for all locations of the kitchen. Hence, HYP swabbing of large-scale equipment and facilities provides the same level of disinfection as surfactants and can be as beneficial.

Improved surveillance of surgical instruments reprocessing following the variant Creutzfeldt-Jakob disease crisis in England: findings from a three-year survey

BACKGROUND

Sensitive, direct protein-detection methods are now recommended for the inspection of reprocessed reusable surgical instruments in England to reduce the risk of prion transmission.

AIM

To implement an established, highly sensitive method to quantify proteinaceous residues on reprocessed instruments in a Sterile Services Department (SSD) and evaluate its potential impact on service provision.

METHODS

We introduced highly sensitive epifluorescence (EDIC/EF) microscopy in a large SSD. Over three years, we periodically tested two models of washer disinfector using stainless-steel tokens spiked with mouse brain homogenate or Browne test soil for comparison. We also obtained data and feedback from staff who had been using EDIC/EF to examine almost 3000 reprocessed instruments.

FINDINGS

All reprocessed test surfaces harboured residual contamination (up to 258.4 ng from 1-μg spikes). Proximity between surfaces affected decontamination efficacy and allowed cross-contamination. Up to 50 ng de novo proteinaceous contamination was deposited on control surfaces after a single automated washer disinfector (AWD) cycle. The test soil behaved differently than real tissue contamination. SSD staff observed proteinaceous residues on most reprocessed instruments using EDIC/EF, which can detect far smaller amounts than the currently accepted national threshold of 5 μg per side.

CONCLUSIONS

Implementing recent national guidelines to address the prions concern proved an eye-opener. Microscopic levels of proteins remain on many reprocessed instruments. The impact most of these residues, potentially including prions, may have on subsequent patients after sterilization remains debatable. Improving surveillance capability in SSDs can support decision making and raise the standards of surgical instruments reprocessing.