Luminol-based forensic detection of latent blood; an approach to rapid wide-area screening combined with Glo-Germ oil simulant studies

Prophylactic Dressings for Maintaining Skin Integrity of Healthcare Workers When Using N95 Respirators While Preventing Contamination Due to the Novel Coronavirus: A Quality Improvement Project

PURPOSE

Extended use of N95 respirator masks is far more prevalent during the coronavirus disease 2019 (COVID-19) pandemic. As WOC nurses, we were tasked with formulating procedures for protecting the facial skin integrity of healthcare workers (HCWs) using personal protective devices when caring for patients with suspected or active COVID-19, while avoiding contamination when the masks are donned or doffed. This quality improvement project describes how we approached this project within the limited time frame available as we cared for patients with established and suspected COVID-19.

PARTICIPANTS AND SETTING

This project focused on HCW use of N95 respirator masks and dressings currently available in our facility. The 4 WOC nurses acted as quality improvement project directors and as participants. The setting for our project was our facility's simulation laboratory.

APPROACH

We evaluated 6 topical products (an alcohol-free liquid acrylate, thin film dressing, thin hydrocolloid dressing, hydrocolloid blister care cushion, thin foam transfer dressing, and thick foam dressing) applied to skin in contact with 3 N95 respirators; all are available on our facility's formulary and all are in widespread clinical use. After the product was applied to the face and nose, the N95 respirator was donned and evaluated for fit. Participants then wore the devices for 10 hours and doffed the mask using established facility procedures. In order to evaluate for potential contamination including possible aerosolization, we applied a commercially available fluorescent lotion to simulate the presence of infectious particles. Contamination was assessed using an ultraviolet light for all dressings except for the alcohol-free liquid acrylate. We also evaluated cutaneous responses (skin integrity, irritation, comfort) during this period.

OUTCOMES

We found that contamination of the simulated pathogen did not occur with removal of any of the protective products. No skin irritation was noted with any of the tested products after a 10-hour wear time underneath the N95 respirator masks, but mild discomfort was experienced with 3 of the dressings (thin film dressing and both hydrocolloid dressings).

CONCLUSION

Based on these experiences, we recommend application of an alcohol-free liquid acrylate film to prevent facial skin injury associated with friction from the extended use of an N95 respirator mask. We further recommend performing a fit test and user-performed seal check with the use of any topical dressing and especially those that add cushion. For the duration of the COVID-19 pandemic, we recommend use of protective dressings to maintain skin integrity and protection from coronavirus infection as HCWs continue to provide care to all of patients under their care.

Identification of female-specific blood stains using a 17β-estradiol-targeted aptamer-based sensor

Blood stain evidence obtained from a violent crime scene provides decisive clues that can enable a case to be solved through forensic analyses such as genetic identification. However, collected samples usually contain a mixture of biological material from different sources, making genetic identification difficult. To address this issue, we developed an activatable aptamer sensor targeting 17β-estradiol for detection of female-specific blood in mixed samples. With the sensor, we were able to detect blood originating from females using a variable light source (495 nm). The sensor was especially sensitive to blood from young females (10-40 years) but not to blood from older females (≥ 50 years). Genomic DNA was extracted from the female blood specimens identified by this method and used for quantification and short tandem repeat genotyping. We confirmed that there was no fluorescence interference from the aptamer sensor. These results indicate that this novel aptamer sensor can be used to analyze evidentiary blood samples and thereby facilitate subsequent genetic identification.

Tracking cross-contamination transfer dynamics at a mock retail deli market using GloGerm

Ready-to-eat (RTE) deli meats are considered a food at high risk for causing foodborne illness. Deli meats are listed as the highest risk RTE food vehicle for Listeria monocytogenes. Cross-contamination in the retail deli market may contribute to spread of pathogens to deli meats. Understanding potential cross-contamination pathways is essential for reducing the risk of contaminating various products. The objective of this study was to track cross-contamination pathways through a mock retail deli market using an abiotic surrogate, GloGerm, to visually represent how pathogens may spread through the deli environment via direct contact with food surfaces. Six contamination origination sites (slicer blade, meat chub, floor drain, preparation table, employee's glove, and employee's hands) were evaluated separately. Each site was inoculated with 20 ml of GloGerm, and a series of standard deli operations were completed (approximately 10 min of work). Photographs were then taken under UV illumination to visualize spread of GloGerm throughout the deli. A sensory panel evaluated the levels of contamination on the resulting contaminated surfaces. Five of the six contamination origination sites were associated with transfer of GloGerm to the deli case door handle, slicer blade, meat chub, preparation table, and the employee's gloves. Additional locations became contaminated (i.e., deli case shelf, prep table sink, and glove box), but this contamination was not consistent across all trials. Contamination did not spread from the floor drain to any food contact surfaces. The findings of this study reinforce the need for consistent equipment cleaning and food safety practices among deli workers to minimize cross-contamination.

Sharps management and the disposal of clinical waste

Dangerous errors in clinical waste management continue to occur and inappropriate items find their way into clinical waste sacks that are not designed to hold sharp or heavy items, or fluids. Although great attention is given to the safe use of sharps, needles still find their way into waste sacks instead of a sharps bin. Sharps injuries among ancillary and support staff, and waste handlers working in the disposal sector, can occur at a rate greater than for health-care staff. Blood and body fluid exposures from carelessly packaged clinical waste are similarly common, with almost 100% of waste handlers having blood splashes on their clothing within four hours of starting a shift. Blood splashes are also common on the outside surfaces of sharps bins and on the frames supporting clinical waste sacks. Using forensic techniques, blood residues invisible to the naked eye can be detected on all surfaces of most sharps bins and on the bench top, walls and floor where the bins were positioned. Care is required when disposing of clinical waste, to protect and maintain the immediate environment from contamination, and to ensure the safety of those who come into contact with waste as it passes along the disposal chain.