Changing Strategies for the Detection of Bacteria in Platelet Components in Ireland: From Primary and Secondary Culture (2010-2020) to Large Volume Delayed Sampling (2020-2023).

Bacterial contamination of platelet components (PC) poses the greatest microbial risk to recipients, as bacteria can multiply over the course of PC storage at room temperature. Between 2010 and 2020, the Irish Blood Transfusion Service (IBTS) screened over 170,000 buffy coat-derived pooled (BCDP) and single-donor apheresis platelets (SDAPs) with the BACT/ALERT 3D microbial detection system (Biomerieux, L'Etoile, France), using a two-step screening protocol which incorporated primary and secondary cultures. Although the protocol was successful in averting septic transfusion reactions (STRs), testing large sample volumes at later time points was reported to improve detection of bacterial contamination. A modified large-volume delayed sampling (LVDS)-type protocol was adopted in 2020, which in the case of SDAP was applied to collections rather than individual splits (2020-2023, 44,642 PC screened). Rates of bacterial contamination for BCDP were 0.125% on Day-2, 0.043% on Day-4 vs. 0.191% in the post-LVDS period. SDAP contamination rates in the pre-LVDS period were 0.065% on Day-1, 0.017% on Day-4 vs. 0.072% in the post-LVDS period. Confirmed STRs were absent, and the interdiction rate for possibly contaminated SDAP was over 70%. In the post-LVDS period, BCDPs had a higher total positivity rate than SDAPs, 0.191% (1:525) versus 0.072% (1:1385), respectively, (chi-squared 12.124, 1 df, p = 0.0005). The majority of organisms detected were skin-flora-type, low pathogenicity organisms, including coagulase-negative staphylococci and Cutibacterium acnes, with little change in the frequency of clinically significant organisms identified over time. Both protocols prevented the issue of potentially harmful components contaminated (rarely) with a range of pathogenic bacteria, including Escherichia coli, Serratia marcesens, Staphylococcus aureus, and streptococci. Culture positivity of outdates post-LVDS whereby 100% of expired platelets are retested provides a residual risk estimate of 0.06% (95% CI 0.016-0.150). However, bacterial contamination rates in expired platelets did not demonstrate a statistically significant difference between the pre-LVDS 0.100% (CI 0.033-0.234) and post-LVDS 0.059% (0.016-0.150) periods (chi-squared = 0.651, 1 df, p = 0.42).

Designing spaces to support collaborative creativity in shared virtual environments.

Shared virtual environments (SVEs) have been researched extensively within the fields of education, entertainment, work, and training, yet there has been limited research on the creative and collaborative aspects of interactivity in SVEs. The important role that creativity and collaboration play in human society raises the question of the way that virtual working spaces might be designed to support collaborative creativity in SVEs. In this paper, we outline an SVE named LeMo, which allows two people to collaboratively create a short loop of music together. Then we present a study of LeMo, in which 52 users composed music in pairs using four different virtual working space configurations. Key findings indicated by results include: (i) Providing personal space is an effective way to support collaborative creativity in SVEs, (ii) personal spaces with a fluid light-weight boundary could provide enough support, worked better and was preferable to ones with rigid boundaries and (iii) a configuration that provides a movable personal space was preferred to one that provided no mobility. Following these findings, five corresponding design implications for shared virtual environments focusing on supporting collaborative creativity are given and conclusions are made.

A large-scale study of respiratory virus infection over 2 years using the Luminex xTAGRVP assay.

Traditional methods of detecting and identifying respiratory viruses like cell culture and immunofluorescence are labor intensive, often slow, and are dependent on specimen viability. As a result, there has been a shift in laboratory practices from these methods to molecular-based techniques such as polymerase chain reaction, which can be faster, more sensitive, and less labor intensive than traditional methods. The Food and Drug Administration approved version of the Luminex xTAG respiratory viral panel (RVP) assay detects 12 respiratory viruses simultaneously. We evaluated the performance of the RVP assay, on over 8,000 nasopharyngeal specimens during a 2-year period. Approximately 70% of all specimens tested were positive for at least one respiratory virus. Influenza A (Inf A) was the most prevalent, followed by respiratory syncytial virus. The RVP assay also detected the newly emerging Inf A porcine H1N1 that started to circulate in 2008. However, it could not identify it to subtype level and required further confirmatory tests. This study shows that the RVP assay is an invaluable tool in monitoring seasonal outbreaks and pandemic events. It not only detects newly emerging influenza strains, but also allows the throughput of thousands of clinical specimens in a timely manner, reducing the turnaround time from weeks to days, when compared to cell culture.

Development of a department of defense regional viral respiratory surveillance program.

A continuous viral respiratory surveillance program was established throughout the U.S. Department of Defense beneficiary population living in Europe with a few specimens coming from the Middle East. This program provided influenza rapid antigen test kits, specimen collection kits, detailed instructions, and a questionnaire. Training on specimen collection and testing was provided to health care providers and lab staff. We received 1875 patient specimens (39% active duty, 13% adult beneficiary, and 48% pediatric beneficiary) collected from 36 medical treatment facilities in 10 European and Middle Eastern countries over a 52-week period. Nine hundred and twenty-two questionnaires were received. The greatest activity of viral respiratory infections occurred between weeks 7 to 13. We found the sensitivity of rapid antigen testing compared poorly to both viral culture and PCR; however, the information provided by the rapid testing was utilized locally for guiding patient treatment. Additionally, although 91% of the active duty population received the influenza vaccine, we calculated the vaccine efficacy to be 52%.