Page 165 - Assurance of Sterility for Sensitive Combination Products and Materials

Preventing health care associated infections 147

agents. Microbes associated with these biofilms are much less susceptible
to antibiotics and are difficult to remove from reusable medical devices. In
addition, biofilms resist attack and elimination by the host immune system.
The biofilm can form from a single bacterial source but often consists of
several types of different microorganisms. Biofilm can originate from a
patient’s skin microflora, exogenous microflora from HCWs, or from con-
taminated intravenous fluids. Different types of bacteria secrete different
polymers with different adhesion properties to attach to surfaces. Bacterial
colonization of a medical device can not only impact infection, but it can
also affect function of the device. Joint prosthesis has been shown to loosen
due to biofilm formation.

Industrial single-use devices
Terminal sterilization is the gold standard for single-use devices. A conser-
vative overkill approach has been extremely effective at minimizing the risk
to the patient. Over the past two decades, the CDC has developed one of
the most comprehensive data sets tracking HAIs. This has provided insights
on the root cause of infection risk to the patient.
The largest signal of inputs that impacts HAIs were due to behavior and
procedural contamination of the single-use devices or from challenges to
sterilize multiple use devices and not from inadequately sterilized single-use
devices. Simple activities such as washing hands as well as more compli-
cated activities such as setting up a sterile operation field and using aseptic
techniques during the procedure has had a large impact on reducing in-
fection. It is also noteworthy that the data collection method is sensitive
enough to detect increases in infection rates during the recent incident
when duodenoscopes were improperly cleaned prior to disinfection or
sterilization. On September 26, 2008 the US Government Accountability
Office released GAO report number GAO-09-1091R entitled “Health-
Care-Associated Infections in Hospitals: Number Associated with Medical
Devices Unknown, but Experts Report Provider Practices as a Significant
Factor.” Per this report the most significant factor affecting the occurrence
of HAIs is health-care professionals’ improper patient examination and
treatment practices. In addition, about half of the 11 experts interviewed
for the report cited inadequate preparation of a device for sterilization and
improper storage as significant factors in HAIs associated with multiuse
medical devices. None of the experts interviewed, nor review of identified
relevant articles cited sterilization of single-use devices as a causative factor
in HAIs [11].