Fit testing and comfort evaluation of prophylactic dressing use for healthcare workers under N95/P2 respirators in one health service district in Australia.

BACKGROUND: This study evaluated the use of prophylactic dressings (silicone foam, silicone tape, hydrocolloid) under N95/P2 respirators to determine which dressings fit successfully. AIM: The aim was to develop a health service protocol for one state in Australia. METHODS: Data were collected during August and September 2021 as part of the Respiratory Protection Programme on 600 health workers using three types of prophylactic dressings. Five different types of respirators were used. Participant healthcare workers rated comfort on a four-point Likert scale. RESULTS: Successful fit was achieved by 63.6% of the respirator-dressing combinations. The best-performing respirator-dressing combination was the Trident® respirator with dressing Mepilex® Lite silicone foam (90.2% pass rate). High pass rates were found in the Trident® respirator with Mepilex® Border Lite with SofSicure silicone tape (79.1%); the 3M™ 1860 respirator with Mepilex® Border Lite with SofSicure silicone tape (74%); and the BSN orange duckbill respirator with Mepilex® Lite silicone foam (69.8%). The poorest-performing combination was the BYD™ respirator with Mepilex® Border Lite with SofSicure silicone tape (25.9% pass rate). Uncorrected chi-squared tests for association revealed significant associations between dressing type and outcome (P=0.004) and respirator type and outcome (P<0.001). Most respondents (82%) found the dressing combination markedly comfortable. CONCLUSIONS: When using prophylactic dressings under N95/P2 respirators, it is necessary to perform a fit test. In this study Trident® respirators had the highest probability of successful fit, while BYD™ respirators had the lowest. Combining Trident® respirators with Mepilex® Lite dressing was optimal. Most participants reported greater comfort with the dressings under the respirators.

Antimony leaching and chemical species analyses in an industrial solid waste: Surface and bulk speciation using ToF-SIMS and XANES.

The surface chemistry and bulk chemical speciation of solid industrial wastes containing 8wt-% antimony (Sb) were investigated using synchrotron X-ray Absorption Near Edge Structure (XANES) and Time-of-Flight Ion Secondary Mass Spectrometry (ToF-SIMS). Leaching experiments were conducted in order to better understand the behavior of Sb in waste streams and to inform regulatory management of antimony-containing wastes. The experiments also demonstrate how a combination of XANES and ToF-SIMS adds value to the field of waste investigations. Leaching treatments (acid and base) were performed at a synchrotron over 24h time periods. Surface analyses of the wastes before leaching showed the presence of Sb associated with S and O. Bulk analyses revealed Sb to be present, primarily, as trivalent sulfide species. Both acid and base leaching did not change the antimony speciation on the solid. Leaching transferred about 1% of the total Sb into solution where Sb was found to be present as Sb(V). XANES data showed similarities between leachate and FeSbO4. During base leaching, the Sb content in solution gradually increased over time, and potential desorption mechanisms are discussed.

First Report of Melampsora larici-populina on Populus spp. in Eastern North America.

In September 2002, yellow spots were observed on the leaf surface of a hybrid poplar (Populus maximowiczii Henry × P. balsamifera L.) grown at the Berthier forest nursery (46°2'N, 73°11'W) in the St. Lawrence Valley (Lanaudière Region, Québec, Canada). Disease severity was low, but the pathogen was present on a hybrid that was previously thought to be resistant to Melampsora medusae Thuem, the only reported poplar rust in eastern North America. Uredinia typical of a Melampsora sp. were observed on the abaxial leaf surface. The observed urediniospores were longer (32 to 48 µm) than the expected range for M. medusae (23 to 35 µm) and possessed an apical bald spot; thick paraphyses were also observed. These characteristics are diagnostic of M. larici-populina Kleb (2). Samples were deposited in the National Mycological Herbarium of Canada (DAOM 232107 and 232108) and in the Quebec Forest Biology Herbarium (QFB14703 and 14704). DNA was extracted from uredinia, and the internal transcribed spacer (ITS) of the ribosomal RNA gene was amplified and sequenced (GenBank Accession Nos. AY429656 and AY429657). There was a 100% match between the two sequences obtained and that of M. larici-populina (GenBank Accession No. AY375267), but there was approximately 12% divergence with the ITS sequence of M. medusae (GenBank Accession No. AY375273-5). This is the first report of M. larici-populina in eastern North America. This fungus was reported on P. trichocarpa × P. deltoides hybrids in the western United States in the early 1990s (1). It appears that M. larici-populina can overwinter in Québec because it was observed again at the nursery in September 2003. The occurrence of M. larici-populina in eastern North America has direct implications for the poplar industry since the host specificities of M. medusae and M. larici-populina differ; P. balsamifera and P. maximowiczii are sensitive to M. larici-populina (3). Hybrids with P. balsamifera or P. trichocarpa components may be particularly at risk. References: (1) G. Newcombe and G. A. Chastagner. Plant Dis. 77:532, 1993. (2) J. Pinon. Eur. J. For. Pathol. 3:221, 1973. (3) J. Pinon. Silvae Genet. 41:25, 1992.

Identifying and separating the effects of practice and of cognitive ageing during a large longitudinal study of elderly community residents.

In protracted longitudinal studies of cognitive changes in old age volunteers must be repeatedly tested. Even with intervals of several years between assessment, this raises the possibility that improvements due to practice mask other changes. This problem is much more acute in brief studies of cognitive changes associated with progressive pathologies such as Alzheimer's disease or the effects of clinical interventions. Both types of study also encounter problems of selective dropout of frail and less able individuals leaving relatively 'elite' survivors. An analysis of data from repeated testing at 2-3 years intervals on the AH4 (1) intelligence test is presented to illustrate how a random effects model can be used to identify and disassociate age-related changes and practice effects at the population level, after effects of selective dropout and of background demographical variables have been taken into consideration. This analysis also provides some new, substantive empirical findings. Age-related changes are relatively slight between 49 and 70 years but much more marked between 70 and 80 years. Even with assessment points, several years apart the population average effect of practice is large relative to that of age-related change. Variation between individuals increases as samples age, providing the first clear evidence from a longitudinal study for marked individual differences in trajectories of cognitive ageing.

Chasing coccidia--new tools enter the race.

The 8th International Coccidiosis Conference, held on 9--13 July 2001 in Palm Cove, Australia, was a showcase of the latest studies on widely known coccidia, including Eimeria and Toxoplasma in addition to the emerging or re-emerging parasites such as Neospora, Cryptosporidium and Cyclospora. This meeting was staged in conjunction with the Annual Scientific Meeting of the Australian Society for Parasitology.