Corneas procured after death are susceptible to contamination by microorganisms; thus, pre-storage decontamination, sterile processing techniques, and the incorporation of antimicrobials into the storage medium are routinely employed. Despite their potential uses, corneas are discarded if there is contamination from microorganisms. Following cardiac arrest, corneas are ideally collected within 24 hours, according to professional guidelines, but may be procured up to 48 hours later. Our mission was to evaluate the contamination risk in relation to the period following death and the type of microbes isolated.
Corneas were treated with 0.5% povidone-iodine and tobramycin to decontaminate them prior to procurement. Stored in organ culture medium, they were then subjected to microbiological testing after 4-7 days of storage. Microbiology testing results from 2016 to 2020 were retrospectively analyzed for samples from two blood bottles (aerobic, anaerobic/fungi, Biomerieux) each containing ten milliliters of cornea preservation medium after incubation for seven days. Four groups of corneas were distinguished by post-mortem interval: Group A: less than 8 hours, Group B: 8 to 16 hours, Group C: 16 to 24 hours, and Group D: over 24 hours. An analysis was conducted on the contamination rate and the types of microorganisms isolated from each of the four groups.
In 2019, a batch of 1426 corneas underwent organ culture storage and were subjected to a microbiological evaluation protocol. Contamination was detected in 65 (46%) of the 1426 corneas examined. A total of 28 bacterial and fungal isolates were obtained. The Saccharomycetaceae fungi, group B, showed a high prevalence (781%) of bacterial isolates belonging to the Moraxellaceae, Staphylococcaceae, Morganellaceae, and Enterococcaceae families. Within the microbial community of group C, the presence of Enterococcaceae, Moraxellaceae bacterial families, and Saccharomycetaceae fungal family was very common (70.3%). The Enterobacteriaceae, a group D bacterial family, were isolated with a frequency of 100%.
Organ culture serves as a tool for isolating and discarding microbiologically affected corneas. Our study revealed a relationship between longer post-mortem durations and elevated rates of microbial contamination in corneal specimens, suggesting a link between the contaminations and donor post-mortem changes rather than previous infections. The superior quality and safety of the donor cornea depend on comprehensive disinfection procedures and a minimized post-mortem interval.
Corneas harboring microbial contamination are identifiable and removable using organ culture. The study's results demonstrate a greater rate of microbial contamination in corneal samples from donors with prolonged post-mortem intervals, supporting the notion that this contamination may originate from post-mortem changes in the donor rather than pre-existing infections. For maximum quality and safety of the donor cornea, disinfection of the cornea and minimizing the duration of the post-mortem interval are essential actions.
The Liverpool Research Eye Bank (LREB) expertly curates and stores ocular tissues, playing a vital role in research projects addressing ophthalmic diseases and the potential development of new treatments. The Liverpool Eye Donation Centre (LEDC) supports our efforts to collect complete eyes from deceased donors. The LEDC's screening process for potential donors involves approaching next-of-kin for consent on behalf of the LREB; however, variables like transplant compatibility, time limitations, medical contraindications, and other complications can diminish the available donor pool. COVID-19 has constituted a major barrier to donation activities during the preceding twenty-one months. The objective of the research was to evaluate the degree to which the COVID-19 crisis affected donations received by the LREB.
From January 2020 through October 2021, the LEDC constructed a comprehensive database documenting the outcomes of decedent screens performed at The Royal Liverpool University Hospital Trust. The data indicated the suitability of each deceased individual for transplantation, research, or both, along with the specific number of deceased individuals deemed unsuitable for either purpose due to COVID-19 infection at the time of death. In the data set, the number of families approached for donations related to research, the number who provided consent, and the number of tissue samples collected were all represented.
The LREB did not collect any tissues from those who died in 2020 and 2021 and had COVID-19 recorded on their death certificates. The number of unsuitable organ donors for transplant or research significantly climbed due to COVID-19 positivity, notably throughout the period from October 2020 to February 2021. This ultimately caused a reduction in the number of approaches to the next of kin. Undoubtedly, COVID-19 did not appear to be directly linked to a decline in the total amount of donations. Monthly donor consent, varying from 0 to 4 individuals, remained uncorrelated with the peak months of COVID-19 mortality over the 21-month period.
COVID-19 case counts appear to have no bearing on donor numbers, implying alternative factors drive donation levels. Elevated awareness of potential research donation opportunities may bolster donation rates. Crafting informational materials and coordinating outreach events will play a significant role in this effort.
The disconnection between COVID-19 case counts and donor numbers points to factors outside of the pandemic impacting donation levels. A heightened understanding of the significance of research donations could stimulate a greater willingness to contribute financially. Oral relative bioavailability Aiding in this endeavor will be the development of informational resources and the planning of outreach activities.
The coronavirus, SARS-CoV-2, has presented humankind with a collection of previously unseen difficulties. As the crisis escalated across many countries, it put pressure on the German health system, necessitating increased care for coronavirus-affected patients while simultaneously leading to the cancellation or delay of scheduled, elective procedures. skin infection There was a direct relationship between this action and the outcome for tissue donation and transplantation. The DGFG network's corneal donation figures suffered a significant downturn due to the initial pandemic lockdowns in Germany. Activities, having enjoyed a period of freedom during the summer, faced renewed limitations starting in October amidst the mounting infection figures. Pemetrexed 2021 saw a related pattern. The already meticulous screening of prospective tissue donors was broadened in compliance with Paul-Ehrlich-Institute directives. In contrast, this significant action prompted a rise in discontinued donations, stemming from medical contraindications, increasing from 44% in 2019 to 52% in 2020 and 55% in 2021 (Status November 2021). Although the 2019 figures for donation and transplantation were surpassed, DGFG maintained a steady level of patient care in Germany, demonstrating a consistent performance relative to other European countries. The positive outcome is, in part, attributable to the increased consent rate of 41% in 2020 and 42% in 2021, largely a result of the elevated public sensitivity to health issues during the pandemic. The situation stabilized again in 2021, although the count of donations that could not be realized due to COVID-19 cases in the deceased individuals kept increasing alongside the infection waves. The prevalence of COVID-19 infections varying regionally necessitates a responsive approach to donation and processing procedures. This involves adjusting to local conditions while maintaining essential operations in those regions where transplants are crucial.
Throughout the UK, surgeons receive tissues from the NHS Blood and Transplant Tissue and Eye Services (TES), a multi-tissue bank supporting human tissue transplants. TES's services encompass scientists, clinicians, and tissue banks, with the provision of a range of non-clinical tissues for research, education, and training. A substantial amount of the non-clinical ocular tissue provided encompasses a range of components, including whole eyes, corneas, conjunctiva, lenses, and posterior segments—the latter remaining after corneal removal. Two dedicated full-time staff members work at the TES Research Tissue Bank (RTB), which is a part of the TES Tissue Bank in Speke, Liverpool. Non-clinical tissue is obtained by Tissue and Organ Donation teams that operate in numerous locations across the United Kingdom. The RTB's operations within TES are deeply intertwined with the David Lucas Eye Bank in Liverpool and the Filton Eye Bank in Bristol. TES National Referral Centre Nurses primarily obtain informed consent for non-clinical ocular tissues.
The RTB acquires tissue by means of two different routes. The first path is marked by tissue directly consented and obtained for non-clinical purposes; the second path includes tissue that becomes available after evaluation for clinical viability. The RTB's tissue supply from eye banks predominantly traverses the second pathway. In the year 2021, the RTB distributed over one thousand specimens of non-clinical ocular tissue. Approximately 64% of the tissue was allocated to research projects (including those related to glaucoma, COVID-19, pediatrics, and transplantation). 31% was assigned for clinical training in DMEK and DSAEK procedures, notably for post-pandemic training of new eye bank staff. A small 5% was reserved for internal validation and in-house uses. The research indicated that corneas, extracted from eyes, remain suitable for instructional purposes within a six-month period.
The RTB's cost-recovery model, partial in nature, enabled it to become self-sufficient by 2021. For progress in patient care, the availability of non-clinical tissue is paramount, as demonstrated in several peer-reviewed publications.
The RTB's path to self-sufficiency, a journey grounded in a partial cost-recovery system, concluded in 2021.