Expert opinion on the identification, risk assessment, and mitigation of microorganisms and parasites relevant to xenotransplantation products from pigs.

Xenotransplantation has the potential to address shortages of organs available for clinical transplantation, but concerns exist regarding potential risks posed by porcine microorganisms and parasites (MP) to the health of human recipients. In this study, a risk-based framework was developed, and expert opinion was elicited to evaluate porcine MP based on swine exposure and risk to human health. Experts identified 255 MP to include in the risk assessment. These were rated by experts for five criteria regarding potential swine exposure in the USA and human health risks. MP were subsequently categorized into three risk mitigation groups according to pre-defined rules: disqualifying porcine MP (due to their pathogenic potential, n = 130); non-disqualifying porcine MP (still relevant to consider for biosecurity or monitoring efforts, n = 40); and alert/watch list (not reported in the USA or MP not in swine, n = 85). Most disqualifying (n = 126) and non-disqualifying (n = 36) porcine MP can effectively be eliminated with high biosecurity programs. This approach supports surveillance and risk mitigation strategies for porcine MP in swine produced for xenotransplantation, such as documentation of freedom from porcine MP, or use of porcine MP screening, monitoring, or elimination options. To the authors' knowledge, this is the first effort to comprehensively identify all relevant porcine MP systematically and transparently evaluate the risk of infection of both donor animals and immunosuppressed human recipients, and the potential health impacts for immunosuppressed human recipients from infected xenotransplantation products from pigs.

Pathogen elimination and prevention within a regulated, Designated Pathogen Free, closed pig herd for long-term breeding and production of xenotransplantation materials.

BACKGROUND: We established a Source Animal (barrier) Facility (SAF) for generating designated pathogen-free (DPF) pigs to serve as donors of viable organs, tissues, or cells for xenotransplantation into clinical patients. This facility was populated with caesarian derived, colostrum deprived (CDCD) piglets, from sows of conventional-specific (or specified) pathogen-free (SPF) health status in six cohorts over a 10-month period. In all cases, CDCD piglets fulfilled DPF status including negativity for porcine circovirus (PCV), a particularly environmentally robust and difficult to inactivate virus which at the time of SAF population was epidemic in the US commercial swine production industry. Two outbreaks of PCV infection were subsequently detected during sentinel testing. The first occurred several weeks after PCV-negative animals were moved under quarantine from the nursery into an animal holding room. The apparent origin of PCV was newly installed stainless steel penning, which was not sufficiently degreased thereby protecting viral particles from disinfection. The second outbreak was apparently transmitted via employee activities in the Caesarian-section suite adjacent to the barrier facility. In both cases, PCV was contained in the animal holding room where it was diagnosed making a complete facility depopulation-repopulation unnecessary. METHOD: Infectious PCV was eliminated during both outbreaks by the following: euthanizing infected animals, disposing of all removable items from the affected animal holding room, extensive cleaning with detergents and degreasing agents, sterilization of equipment and rooms with chlorine dioxide, vaporized hydrogen peroxide, and potassium peroxymonosulfate, and for the second outbreak also glutaraldehyde/quaternary ammonium. Impact on other barrier animals throughout the process was monitored by frequent PCV diagnostic testing. RESULT: After close monitoring for 6 months indicating PCV absence from all rooms and animals, herd animals were removed from quarantine status. CONCLUSION: Ten years after PCV clearance following the second outbreak, due to strict adherence to biosecurity protocols and based on ongoing sentinel diagnostic monitoring (currently monthly), the herd remains DPF including PCV negative.

Outpatient cataract surgery: incident and procedural risk analysis do not support current clinical ophthalmology guidelines.

OBJECTIVE: To evaluate whether an ophthalmologist-led, non-anesthesia-supported, limited monitoring pathway for phacoemulsification/intraocular lens cataract surgery, can be performed safely with only a medical emergency team providing support. DESIGN: Retrospective, observational, cohort study. PARTICIPANTS: All patients who underwent elective phacoemulsification/intraocular lens surgery under topical anesthesia in the ophthalmology outpatient unit between January 1, 2011, and December 31, 2012. METHODS: Cataract surgery was performed by phacoemulsification under topical anesthesia. The intake process mainly embraced ophthalmic evaluation, obtaining a medical history, and proposing the procedure. A staff ophthalmologist performed the procedure assisted by 2 registered nurses in an independent outpatient clinic operating room within the hospital. The clinical pathway was without dedicated presence of or access to anesthesia service. Perioperative monitoring was limited to blood pressure and plethysmography preoperatively and intraoperatively. Patients were offered supportive care and instructed to avoid fasting and continue all their chronic medication. MAIN OUTCOME MEASURES: The primary outcome measure was the incidence of adverse events requiring medical emergency team (MET) interventions throughout the pathway. Secondary outcome measures were surgical ocular complication rates, use of oral sedatives, and reported reasons to perform the surgery in the classical operation room complex. RESULTS: Within the cataract pathway, 6961 cases (4347 patients) were eligible for analysis. Three MET interventions related to the phacoemulsification/intraocular lens pathway occurred in the 2-year study period, resulting in an intervention rate of 0.04%. None of the interventions was intraoperative. All 3 patients were diagnosed as vasovagal collapse and recuperated uneventfully. No hospital admittance was required. Eight other incidents occurred within the general ophthalmology outpatient unit population during the study period. CONCLUSIONS: Cataract surgery can be safely performed in an outpatient clinic, in the absence of the anesthesia service and with limited workup and monitoring. Basic first aid and basic life support skills seem to be sufficient in case of an adverse event. An MET provides a generous failsafe for this low-risk procedure.