Nosocomial infections, also referred to as healthcare-associated or hospital-acquired infections (HAIs), are those which hospitalized patients acquire during medical treatment for another condition that were not present or incubating at the time of admission, unless related to a previous admission. These infections are a significant cause of morbidity and mortality that drive up the cost of healthcare in the United States. Despite all of the efforts to prevent nosocomial infections from occurring, they have not been eliminated and are becoming increasingly difficult to treat. It is also difficult determine factors of significance in the causal pathway, such as tracing an infection back to its source. Devices have been cited as sources of infection, both as modes of transmission and reservoirs, but the origin of the pathogens and their transfer to the device are unknown and not widely studied. This raises questions as to whether the devices become contaminated after they are opened, or if their sterile barriers are breached prior to use. The objective of this research was to examine the effects of hole size, pressure differential, and secondary packaging on microbial ingress of sterile medical device trays. The methods involved aseptically filling sealed, sterile device packages with a known volume of an appropriate growth medium, exposing the packages to an aerosolized microbial challenge, incubating the packages, and inspecting for growth. After creating and refining the test techniques, the research explored the impacts of hole size (10 and 100 μm), pressure differential (0 and -3.78 psi), and secondary packaging (pouches and cartons) on microbial penetration. The specific pressure differential examined simulates an aircraft descending from 8,000 feet or a ground shipment descending from the same elevation. Hole size, pressure differential, and secondary package type all had a statistically significant effect on microbial penetration of the sterile medical device test trays used in the study.
Read
