Prevalence of Sarcocystis calchasi in free-ranging host species: Accipiter hawks and Common Woodpigeon in Germany

The apicomplexan parasite Sarcocystis calchasi (S. calchasi) triggers pigeon protozoal encephalitis, a neurologic disease in columbids. Accipiter hawks have been identified as the final host, and Columbidae and Psittaciformes as intermediate hosts. In this study, 368 free-ranging Accipiter hawks and 647 free-ranging common woodpigeons were sampled in a country-wide study in order to identify the prevalence of S. calchasi in these populations. A semi-nested PCR specific for S. calchasi tested positive in 7.3% (4.9-10.5) of submitted samples from Accipiter hawks. Juvenile Accipiter hawks (13.7%; 7.7-22.0) had a significantly higher infection rate with S. calchasi than adult Accipiter hawks (5.8%; 2.7-9.3). The prevalence of S. calchasi in common woodpigeons was 3.3% (5.4-9.7). Positive pigeons were identified in 14/16 federal states, and a region-dependency was detected, with higher rates of infection in the eastern parts of Germany. The results of this study suggest that the common woodpigeon is a natural reservoir for S. calchasi. In a study of one region for four consecutive years, an increase in prevalence was not detected. Findings indicate that the parasite is not newly introduced to Germany, but rather long established. The prevalence suggests that there is a substantial risk of S. calchasi infections in other free-ranging as well as captive host species

The contribution of X-linked coding variation to severe developmental disorders

Abstract: Over 130 X-linked genes have been robustly associated with developmental disorders, and X-linked causes have been hypothesised to underlie the higher developmental disorder rates in males. Here, we evaluate the burden of X-linked coding variation in 11,044 developmental disorder patients, and find a similar rate of X-linked causes in males and females (6.0% and 6.9%, respectively), indicating that such variants do not account for the 1.4-fold male bias. We develop an improved strategy to detect X-linked developmental disorders and identify 23 significant genes, all of which were previously known, consistent with our inference that the vast majority of the X-linked burden is in known developmental disorder-associated genes. Importantly, we estimate that, in male probands, only 13% of inherited rare missense variants in known developmental disorder-associated genes are likely to be pathogenic. Our results demonstrate that statistical analysis of large datasets can refine our understanding of modes of inheritance for individual X-linked disorders

Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats

In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

Introduction: The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures. Methods: In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025. Findings: Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2–6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5–5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4–10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32–4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23–11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation. Interpretation: After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification

Electrically evoked dendritic pH transients in rat cerebellar Purkinje cells

Our aim was to test the hypothesis that depolarization-induced intracellular pH (pHi) shifts in restricted regions (dendrites) of mammalian neurones might be larger and faster than those previously reported from the cell soma. We used confocal imaging of the pH-sensitive dye, HPTS, to measure pH changes in both the soma and dendrites of whole-cell patch-clamped rat cerebellar Purkinje cells. In the absence of added CO2–HCO3−, depolarization to +20 mV for 1 s caused large (≈0.14 pH units) and fast dendritic acid shifts, whilst the somatic acidifications were significantly smaller (≈0.06 pH units) and slower. The pHi shifts were smaller in the presence of 5 % CO2–25 mm HCO3−-buffered saline (≈0.08 pH units in the dendrites and ≈0.03 pH units in the soma), although a clear spatiotemporal heterogeneity remained. Acetazolamide (50 μM) doubled the size of the dendritic acid shifts in the presence of CO2–HCO3−, indicating carbonic anhydrase activity. Removal of extracellular calcium or addition of the calcium channel blocker lanthanum (0.5 mm) inhibited the depolarization-evoked acid shifts. We investigated more physiological pHi changes by evoking modest bursts of action potentials (≈10 s duration) in CO2–HCO3−-buffered saline. Such neuronal firing induced an acidification of ≈0.11 pH units in the fine dendritic regions, but only ≈0.03 pH units in the soma. There was considerable variation in the size of the pHi shifts between cells, with dendritic acid shifts as large as 0.2-0.3 pH units following a 10 s burst of action potentials in some Purkinje cells. We postulate that these large dendritic pHi changes (pH microdomains) might act as important signals in synaptic function

Direct demonstration of discrete Ca2+ microdomains associated with different isoforms of adenylyl cyclase

Ca2+-sensitive adenylyl cyclases (ACs) orchestrate dynamic interplay between Ca2+ and cAMP that is a crucial feature of cellular homeostasis. Significantly, these ACs are highly selective for capacitative Ca2+ entry (CCE) over other modes of Ca2+ increase. To directly address the possibility that these ACs reside in discrete Ca2+ microdomains, we tethered a Ca2+ sensor, GCaMP2, to the N-terminus of Ca2+-stimulated AC8. GCaMP2-AC8 measurements were compared with global, plasma membrane (PM)-targeted or Ca2+-insensitive AC2-targeted GCaMP2. In intact cells, GCaMP2-AC8 responded rapidly to CCE, but was largely unresponsive to other types of Ca2+ rise. The global GCaMP2, PM-targeted GCaMP2 and GCaMP2-AC2 sensors reported large Ca2+ fluxes during Ca2+ mobilization and non-specific Ca2+ entry, but were less responsive to CCE than GCaMP2-AC8. Our data reveal that different AC isoforms localize to distinct Ca2+-microdomains within the plasma membrane. AC2, which is regulated via protein kinase C, resides in a microdomain that is exposed to a range of widespread Ca2+ signals seen throughout the cytosol. By contrast, a unique Ca2+ microdomain surrounds AC8 that promotes selectivity for Ca2+ signals arising from CCE, and optimizes CCE-mediated cAMP synthesis. This direct demonstration of discrete compartmentalized Ca2+ signals associated with specific signalling proteins provides a remarkable insight into the functional organization of signalling microdomains