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•PRN473 blocks CLEC-2–mediated platelet function in vitro and ex vivo and reduces thrombosis in 2 mouse models of venous thrombosis.•The data and lack of bleeding in PRN1008/rilzabrutinib clinical trials suggest a future use in immune-mediated thrombosis.

ObjectiveTo determine the rates of asymptomatic viral carriage and seroprevalence of SARS-CoV-2 antibodies in healthcare workers.DesignA cross-sectional study of asymptomatic healthcare workers undertaken on 24/25 April 2020.SettingUniversity Hospitals Birmingham NHS Foundation Trust (UHBFT), UK.Participants545 asymptomatic healthcare workers were recruited while at work. Participants were invited to participate via the UHBFT social media. Exclusion criteria included current symptoms consistent with COVID-19. No potential participants were excluded.InterventionParticipants volunteered a nasopharyngeal swab and a venous blood sample that were tested for SARS-CoV-2 RNA and anti-SARS-CoV-2 spike glycoprotein antibodies, respectively. Results were interpreted in the context of prior illnesses and the hospital departments in which participants worked.Main outcome measureProportion of participants demonstrating infection and positive SARS-CoV-2 serology.ResultsThe point prevalence of SARS-CoV-2 viral carriage was 2.4% (n=13/545). The overall seroprevalence of SARS-CoV-2 antibodies was 24.4% (n=126/516). Participants who reported prior symptomatic illness had higher seroprevalence (37.5% vs 17.1%, χ2=21.1034, p<0.0001) and quantitatively greater antibody responses than those who had remained asymptomatic. Seroprevalence was greatest among those working in housekeeping (34.5%), acute medicine (33.3%) and general internal medicine (30.3%), with lower rates observed in participants working in intensive care (14.8%). BAME (Black, Asian and minority ethnic) ethnicity was associated with a significantly increased risk of seropositivity (OR: 1.92, 95% CI 1.14 to 3.23, p=0.01). Working on the intensive care unit was associated with a significantly lower risk of seropositivity compared with working in other areas of the hospital (OR: 0.28, 95% CI 0.09 to 0.78, p=0.02).Conclusions and relevanceWe identify differences in the occupational risk of exposure to SARS-CoV-2 between hospital departments and confirm asymptomatic seroconversion occurs in healthcare workers. Further investigation of these observations is required to inform future infection control and occupational health practices.

Thrombosis is a frequent, life-threatening complication of systemic infection associated with multiple organ damage. We have previously described a novel mechanism of inflammation-driven thrombosis induced by Salmonella Typhimurium infection of mice. Thrombosis in the liver develops 7 days after infection, persisting after the infection resolves, and is monocytic cell dependent. Unexpectedly, thrombosis was not prominent in the spleen at this time, despite carrying a similar bacterial burden as the liver. In this study, we show that thrombosis does occur in the spleen but with strikingly accelerated kinetics compared with the liver, being evident by 24 hours and resolving rapidly thereafter. The distinct kinetics of thrombosis and bacterial burden provides a test of the hypothesis that thrombi form in healthy vessels to trap or remove bacteria from the circulation, often termed immunothrombosis. Remarkably, despite bacteria being detected throughout infected spleens and livers in the early days of infection, immunohistological analysis of tissue sections show that thrombi contain very low numbers of bacteria. In contrast, bacteria are present throughout platelet aggregates induced by Salmonella in vitro. Therefore, we show that thrombosis develops with organ-specific kinetics and challenge the universality of immunothrombosis as a mechanism to capture bacteria in vivo.

Thrombosis is a frequent, life-threatening complication of systemic infection associated with multiple organ damage. We have previously described a novel mechanism of inflammation-driven thrombosis induced by SalmonellaTyphimurium infection of mice. Thrombosis in the liver develops 7 days after infection, persisting after the infection resolves, and is monocytic cell dependent. Unexpectedly, thrombosis was not prominent in the spleen at this time, despite carrying a similar bacterial burden as the liver. In this study, we show that thrombosis does occur in the spleen but with strikingly accelerated kinetics compared with the liver, being evident by 24 hours and resolving rapidly thereafter. The distinct kinetics of thrombosis and bacterial burden provides a test of the hypothesis that thrombi form in healthy vessels to trap or remove bacteria from the circulation, often termed immunothrombosis. Remarkably, despite bacteria being detected throughout infected spleens and livers in the early days of infection, immunohistological analysis of tissue sections show that thrombi contain very low numbers of bacteria. In contrast, bacteria are present throughout platelet aggregates induced by Salmonellain vitro. Therefore, we show that thrombosis develops with organ-specific kinetics and challenge the universality of immunothrombosis as a mechanism to capture bacteria in vivo.

Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha−1), corresponding to a net carbon uptake of 3.05 Mg C ha−1yr−1, 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha−1) across sites, and this recovery increased with water availability (higher local rainfall and lower climatic water deficit). We present a biomass recovery map of Latin America, which illustrates geographical and climatic variation in carbon sequestration potential during forest regrowth. The map will support policies to minimize forest loss in areas where biomass resilience is naturally low (such as seasonally dry forest regions) and promote forest regeneration and restoration in humid tropical lowland areas with high biomass resilience.

Pragmatic methods to assess the status of biodiversity at multiple scales are required to support conservation decision-making. At the intersection of several major biogeographic zones, Bolivia has extraordinary potential to develop a monitoring strategy aligned with the objectives of the Group on Earth Observations Biodiversity Observation Network (GEO BON). Bolivia, a GEO Observer since 2005, is already working on the adequacy of national earth observations towards the objectives of the Global Earth Observation System of Systems (GEOSS). However, biodiversity is still an underrepresented component in this initiative. The integration of biodiversity into Bolivia’s GEO framework would confirm the need for a country level biodiversity monitoring strategy, fundamental to assess the progress towards the 2020 Aichi targets. Here we analyse and discuss two aspects of the process of developing such a strategy: (1) identification of taxonomic, temporal and spatial coverage of biodiversity data to detect both availability and gaps; and (2) evaluation of issues related to the acquisition, integration and analyses of multi-scale and multi-temporal biodiversity datasets. Our efforts resulted in the most comprehensive biodiversity database for the country of Bolivia, containing 648,534 records for 27,534 species referenced in time and space that account for 92.5% of the species previously reported for the country. We capitalise this information into recommendations for the implementation of the Bolivian Biodiversity Observation Network that will help ensure that biodiversity is sustained as the country continues on its path of development.