Molecular diagnostics of intestinal parasites in returning travellers

A new diagnostic strategy was assessed for the routine diagnosis of intestinal parasites in returning travellers and immigrants. Over a period of 13 months, unpreserved stool samples, patient characteristics and clinical data were collected from those attending a travel clinic. Stool samples were analysed on a daily basis by microscopic examination and antigen detection (i.e. care as usual), and compared with a weekly performed multiplex real-time polymerase chain reaction (PCR) analysis on Entamoeba histolytica, Giardia lamblia, Cryptosporidium and Strongyloides stercoralis. Microscopy and antigen assays of 2,591 stool samples showed E. histolytica, G. lamblia, Cryptosporidium and S. stercoralis in 0.3, 4.7, 0.5 and 0.1% of the cases, respectively. These detection rates were increased using real-time PCR to 0.5, 6.0, 1.3 and 0.8%, respectively. The prevalence of ten additional pathogenic parasite species identified with microscopy was, at most, 0.5%. A pre-selective decision tree based on travel history or gastro-intestinal complaints could not be made. With increased detection rates at a lower workload and the potential to extend with additional parasite targets combined with fully automated DNA isolation, molecular high-throughput screening could eventually replace microscopy to a large extent

Textural and geochemical constraints on andesitic plug emplacement prior to the 2004–2010 vulcanian explosions at Galeras volcano, Colombia

Hazardous sequences of vulcanian explosions are thought to result from the repeated emplacement and destruction of degassed, highly crystalline magma plugs in the shallow conduit of arc volcanoes. The processes governing the timing and magnitude of these explosions are thought to be related to magma ascent rate and efficiency of degassing and crystallisation. We study a rare suite of time-constrained ballistic bombs from the 2004–2010 period of activity of Galeras volcano to reconstruct magma plug architecture prior to six individual vulcanian explosions. We find that each plug was vertically stratified with respect to crystallinity, vesicularity and melt volatile content, melt composition and viscosity. We interpret this structure as resulting from multiple bubble nucleation events and degassing-driven crystallisation during multi-step ascent of the magma forming the plug, followed by spatially variable crystallisation within the plug under contrasting conditions of effective undercooling created by degassing. We propose that the shallow conduit evolved from more open degassing conditions during 2004–2008 to more closed conditions during 2009–2010. This resulted in explosions becoming smaller and less frequent over time during 2004–2008, then larger and more frequent over time during 2009–2010. This evolution was controlled by changing average ascent rates and is recorded by systematic changes in plagioclase microlite textures. Our results suggest that small volume vulcanian explosions (~ 105 m3) should generally be associated with longer repose times (hundreds of days) and produce ballistics characterised by small numbers of large, prismatic plagioclase microlites. Larger volume vulcanian explosions (~ 106 m3) should be associated with shorter repose times (tens of days) and produce ballistics characterised by high numbers of small, more tabular plagioclase microlites

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

In the NadR Regulon, Adhesins and Diverse Meningococcal Functions Are Regulated in Response to Signals in Human Saliva

The Neisseria meningitidis regulator NadR was shown to repress expression of the NadA adhesin and play a major role in NadA phase-variable expression. In this study, we identified through microarray analysis over 30 genes coregulated with nadA in the NadR mutant and defined members of the NadR regulon through in vitro DNA-binding assays. Two distinct types of promoter architectures (I and II) were identified for NadR targets, differing in both the number and position of NadR-binding sites. All NadR-regulated genes investigated were found to respond to 4-hydroxyphenylacetic acid (4HPA), a small molecule secreted in human saliva, which was previously demonstrated to induce nadA expression by alleviating NadR-dependent repression. Interestingly, two types of NadR 4HPA responsive activities were found on different NadR targets corresponding to the two types of genes identified by different promoter architectures: while NadA and the majority of NadR targets (type I) are induced, only the MafA adhesins (type II) are corepressed in response to the same 4HPA signal. This alternate behavior of NadR was confirmed in a panel of strains in response to 4HPA and after incubation in saliva. The in vitro NadR binding activity at type I and type II promoter regions is differentially affected by 4HPA, suggesting that the nature of the NadR binding sites may define the regulation to which they will be subjected. We conclude that NadR coordinates a broad transcriptional response to signals present in human saliva, mimicked in vitro by 4HPA, enabling the meningococcus to adapt to the relevant host niche