Decontaminating N95 respirators during the COVID-19 pandemic: simple and practical approaches to increase decontamination capacity, speed, safety and ease of use.

BACKGROUND: The COVID-19 pandemic has caused a severe shortage of personal protective equipment (PPE), especially N95 respirators. Efficient, effective and economically feasible methods for large-scale PPE decontamination are urgently needed. AIMS: (1) to develop protocols for effectively decontaminating PPE using vaporized hydrogen peroxide (VHP); (2) to develop novel approaches that decrease set-up and take-down time while also increasing decontamination capacity; (3) to test decontamination efficiency for N95 respirators heavily contaminated by make-up or moisturizers. METHODS: We converted a decommissioned Biosafety Level 3 laboratory into a facility that could be used to decontaminate N95 respirators. N95 respirators were hung on metal racks, stacked in piles, placed in paper bags or covered with make-up or moisturizer. A VHP® VICTORY™ unit from STERIS was used to inject VHP into the facility. Biological and chemical indicators were used to validate the decontamination process. FINDINGS: N95 respirators individually hung on metal racks were successfully decontaminated using VHP. N95 respirators were also successfully decontaminated when placed in closed paper bags or if stacked in piles of up to six. Stacking reduced the time needed to arrange N95 respirators for decontamination by approximately two-thirds while almost tripling facility capacity. Make-up and moisturizer creams did not interfere with the decontamination process. CONCLUSIONS: Respirator stacking can reduce the hands-on time and increase decontamination capacity. When personalization is needed, respirators can be decontaminated in labelled paper bags. Make up or moisturizers do not appear to interfere with VHP decontamination.

Use, re-use or discard? Quantitatively defined variance in the functional integrity of N95 respirators following vaporized hydrogen peroxide decontamination during the COVID-19 pandemic.

BACKGROUND: Coronavirus disease 2019 has stretched the ability of many institutions to supply needed personal protective equipment, especially N95 respirators. N95 decontamination and re-use programmes provide one potential solution to this problem. Unfortunately, a comprehensive evaluation of the effects of decontamination on the fit of various N95 models using a quantitative fit test (QNFT) approach is lacking. AIMS: To investigate the effects of up to eight rounds of vaporized hydrogen peroxide (VHP) decontamination on the fit of N95 respirators currently in use in a hospital setting, and to examine if N95 respirators worn by one user can adapt to the face shape of a second user with no compromise to fit following VHP decontamination. METHODS: The PortaCount Pro+ Respirator Fit Tester Model 8038 was used to quantitatively define functional integrity, measured by fit, of N95 respirators following decontamination with VHP. FINDINGS: There was an observable downward trend in the functional integrity of Halyard Fluidshield 46727 N95 respirators throughout eight cycles of decontamination with VHP. Functional integrity of 3M 1870 N95 respirators was reduced significantly after the respirator was worn, decontaminated with VHP, and then quantitatively fit tested on a second user. Furthermore, inconsistencies between qualitative fit test and QNFT results were uncovered that may have strong implications on the fit testing method used by institutions. CONCLUSIONS: The data revealed variability in the functional integrity of different N95 models after VHP decontamination, and exposed potential limitations of N95 decontamination and re-use programmes.

The venous patterns of the cubital fossa in subjects from Brazil.

Venous punctures are among the most common procedures performed by healthcare professionals. In particular, the cubital fossa is the site where the venous accesses are frequently made due to the number of superficial veins and the numerous anastomoses in this region. The arrangement of these venous connections is of particular interest for clinical application in several areas, thus, the healthcare professional must possess knowledge about these vessels and their anatomical relationships. The present study aims to analyze the venous pattern of the cubital fossa among individuals from Brazil. This study was approved by a Research Ethics Committee. The sample had 100 healthy individuals (50 men and 50 women). The superficial veins of the cubital fossa were analyzed with the aid of a sphygmomanometer. When inflated, the pressure in the forearm increased and the veins became prominent. It was observed that in the selected sample the types with the highest prevalence were the Type I and Type VII, both with 22% in 200 limbs studied. The chi2 test showed a significant statistical difference between the anastomosis pattern and the sex of the studied sample. The anastomotic pattern of the superficial veins of the studies sample is similar to African, European and Asian populations. The study of these variations is necessary to provide scientific basis for the healthcare professional during a venipuncture in order to avoid iatrogenic errors and damages in cutaneous nerves or neighboring arteries.

The Y-chromosomal heritage of the Azores Islands population.

The Azores, a Portuguese archipelago located in the north Atlantic Ocean, had no native population when the Portuguese first arrived in the 15th century. The islands were populated mainly by the Portuguese, but Jews, Moorish prisoners, African slaves, Flemish, French and Spaniards also contributed to the initial settlement. To understand the paternal origins and diversity of the extant Azorean population, we typed genomic DNA samples from 172 individuals using a combination of 10 Y-biallelic markers (YAP, SRY-1532, SRY-2627, 92R7, M9, sY81, Tat, SRY-8299, 12f2 and LLY22g) and the following Y-chromosomal STR systems: DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393 and DYS385. We identified nine different haplogroups, most of which are frequent in Europe. Haplogroup J* is the second most frequent in the Azores (13.4%), but it is modestly represented in mainland Portugal (6.8%). The other non-European haplogroups, N3 and E3a, which are prevalent in Asia and sub-Saharan Africa, respectively, have been found in the Azores (0.6% and 1.2%, respectively) but not in mainland Portugal. Microsatellite data indicate that the mean gene diversity (D) value for all the loci analysed in our sample set is 0.590, while haplotype diversity is 0.9994. Taken together, our analysis suggests that the current paternal pool of the Azorean population is, to a great extent, of Portuguese descent with significant contributions from people with other genetic backgrounds.

Characterization of approximately 50 kb of the immunoglobulin VH locus of the Japanese pufferfish, Fugu rubripes.

The variable region of the immunoglobulin heavy chain is created by a somatic rearrangement of a limited number of germline genes. This mechanism of gene assembly [V(D)J recombination] has been found to take place only in jawed vertebrates (gnathostomes). To understand how this mechanism evolved and diversified it is necessary to study the genomic organization of the heavy-chain gene in different vertebrate lineages. Since there is scant sequence information on the VH locus in fish, shotgun sequencing of a cosmid clone containing part of the VH genomic region of the Japanese pufferfish, Fugu rubripes, was undertaken. Eight full-length VH genes were isolated and characterized. They have higher homology to trout genes, but show the same structural features as VHs found in other vertebrates. Two VH subgroups have been identified whose members are interspersed. The frequency of synonymous and nonsynonymous substitution for VH comparisons between family members was found to be higher in the complementarity-determining regions than in the framework regions. Finally, there are four other genes interspersed with the VH genes, one of which is the first full-length retrotransposon element characterized in vertebrates.

Characterization of the recombinase activating gene-1 and 2 locus in the Japanese pufferfish, Fugu rubripes.

The recombinase activating genes (RAG1 and RAG2) encode nuclear proteins that directly mediate the mechanism V(D)J recombination process that occurs in T- and B-lymphocytes. The expression of RAG1 and RAG2 is required for the proper development of maturing lymphocytes. To identify evolutionary conserved regulatory regions adjacent to both genes we isolated and sequenced a cosmid clone containing 43kb of genomic DNA of the Japanese pufferfish, Fugu rubripes. Fugu has a haploid genome of 400Mb and contains the same number of genes as the genome of higher vertebrates. With low abundance of repetitive DNA, the genome of the pufferfish has shown to be ideal for comparative genomics. We found three complete genes, RAG1, RAG2 and ACS (a possible homologue of the plant 1-aminocyclopropane-carboxylate synthase gene). There is also the 5' exon of a prohormone convertase gene, possibly PACE4. The genetic structure of both RAG1 and RAG2 is identical to that found in other fish, but the size of the intergenic region is smaller in Fugu. Expression analysis by RT-PCR shows the presence of RAG transcripts in kidney of adult Fugu. The human ACS was identified in a cosmid assigned to chromosome 11p11, which is close to the location of the RAGs (11p12). This indicates conservation of linkage between human and pufferfish.

B cell and immunoglobulin heterogeneity in carp (Cyprinus carpio L.); an immuno(cyto)chemical study.

B cell and immunoglobulin (Ig) heterogeneity was demonstrated in carp, Cyprinus carpio L., using two monoclonal antibodies (MAbs; WC14, WCI12) produced against carp serum Ig. Immunochemical results showed that both WCI4 and WCI12 react with a protein determinant on the heavy chain of Ig (relative molecular mass approximately 70,000). Immunofluorescence microscopic and flow cytometric analyses of lymphoid cells suggest three distinct subpopulations of B cells and plasma cells: WCI4+12- cells, WCI4-12+ cells, and WCI4+12+ cells. WCI4-12+ and WCI4+12+ anti-DNP antibody-secreting cells were also demonstrated with the ELISPOT assay in pronephros and spleen cell suspensions from primary immunised carp. Affinity chromatography of carp serum and sequential immunoprecipitation of 125I-labelled peripheral blood leucocyte (PBL) membrane proteins only indicated the presence of two antigenically different Ig molecules, i.e., WCI4-12+ and WCI4+12+ molecules. WCI4+12- molecules could not be detected by affinity chromatography or immunoprecipitation. During ontogeny, a shift in percentages of WCI4+12- and WCI4-12+ cells was found in the spleen and the pronephros. In these organs, WCI4+12- cells formed the majority of B cells at 2 weeks of age, but the percentages of this cell type decreased during ontogeny. On the other hand, the percentages of WCI4-12+ cells increased during development, and these cells became the major population of B cells from 13 weeks onward. The proportion of WCI4+12+ cells remained almost constant during ontogeny. The distribution of B cell subpopulations in blood was more or less stable at all ages. The functional significance of Ig heterogeneity in fish and in particular carp is discussed.