Forecasting the risk of pathogen spillover from reservoir populations of wild or domestic animals is essential for the effective deployment of interventions such as wildlife vaccination or culling. ...Due to the sporadic nature of spillover events and limited availability of data, developing and validating robust, spatially explicit, predictions is challenging. Recent efforts have begun to make progress in this direction by capitalizing on machine learning methodologies. An important weakness of existing approaches, however, is that they generally rely on combining human and reservoir infection data during the training process and thus conflate risk attributable to the prevalence of the pathogen in the reservoir population with the risk attributed to the realized rate of spillover into the human population. Because effective planning of interventions requires that these components of risk be disentangled, we developed a multi-layer machine learning framework that separates these processes. Our approach begins by training models to predict the geographic range of the primary reservoir and the subset of this range in which the pathogen occurs. The spillover risk predicted by the product of these reservoir specific models is then fit to data on realized patterns of historical spillover into the human population. The result is a geographically specific spillover risk forecast that can be easily decomposed and used to guide effective intervention. Applying our method to Lassa virus, a zoonotic pathogen that regularly spills over into the human population across West Africa, results in a model that explains a modest but statistically significant portion of geographic variation in historical patterns of spillover. When combined with a mechanistic mathematical model of infection dynamics, our spillover risk model predicts that 897,700 humans are infected by Lassa virus each year across West Africa, with Nigeria accounting for more than half of these human infections.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its resultant clinical presentation, coronavirus disease 2019 (COVID-19), is an emergent cause of mortality worldwide. Cardiac ...complications secondary to this infection are common; however, the underlying mechanisms of such remain unclear. A detailed cardiac evaluation of a series of individuals with COVID-19 undergoing postmortem evaluation is provided, with 4 aims: (1) describe the pathological spectrum of the myocardium; (2) compare with an alternate viral illness; (3) investigate angiotensin-converting enzyme 2 expression; and (4) provide the first description of the cardiac findings in patients with cleared infection.
Study cases were identified from institutional files and included COVID-19 (n=15: 12 active, 3 cleared), influenza A/B (n=6), and nonvirally mediated deaths (n=6). Salient information was abstracted from the medical record. Light microscopic findings were recorded. An angiotensin-converting enzyme 2 immunohistochemical H-score was compared across cases. Viral detection encompassed SARS-CoV-2 immunohistochemistry, ultrastructural examination, and droplet digital polymerase chain reaction.
Male sex was more common in the COVID-19 group (
=0.05). Nonocclusive fibrin microthrombi (without ischemic injury) were identified in 16 cases (12 COVID-19, 2 influenza, and 2 controls) and were more common in the active COVID-19 cohort (
=0.006). Four active COVID-19 cases showed focal myocarditis, whereas 1 case of cleared COVID-19 showed extensive disease. Arteriolar angiotensin-converting enzyme 2 endothelial expression was lower in COVID-19 cases than in controls (
=0.004). Angiotensin-converting enzyme 2 myocardial expression did not differ by disease category, sex, age, or number of patient comorbidities (
=0.69,
=1.00,
=0.46,
=0.65, respectively). SARS-CoV-2 immunohistochemistry showed nonspecific staining, whereas ultrastructural examination and droplet digital polymerase chain reaction were negative for viral presence. Four patients (26.7%) with COVID-19 had underlying cardiac amyloidosis. Cases with cleared infection had variable presentations.
This detailed histopathologic, immunohistochemical, ultrastructural, and molecular cardiac series showed no definitive evidence of direct myocardial infection. COVID-19 cases frequently have cardiac fibrin microthrombi, without universal acute ischemic injury. Moreover, myocarditis is present in 33.3% of patients with active and cleared COVID-19 but is usually limited in extent. Histological features of resolved infection are variable. Cardiac amyloidosis may be an additional risk factor for severe disease.
Highlights • Black race was associated with better oVEMP function (shorter n10 latency and greater peak-to-peak amplitude) across the age range. • Ocular VEMP latency and amplitude, along with ...cervical VEMP corrected amplitude, exhibit age-related declines. • Cardiovascular risk factors, including hypertension, diabetes mellitus, hyperlipidemia, and smoking history, had no associations with VEMP latency, amplitude or asymmetry ratio.
Lambl excrescences (LEs) were initially described in the mid-1800s during autopsies of human hearts, and their significance and biology have been debated ever since. LEs are typically found on aortic ...and pulmonary valve (semilunar) cusps. There is debate concerning whether LEs are a significant cause of thromboembolic events, or whether they are harmless growths. However, there have not been many reports discussing LEs, and fewer still have examined the prevalence and characteristics of LEs in healthy human hearts. Those who have examined LE prevalence have reported a very high incidence of LEs (85-90%). Herein, we examine LE prevalence and characteristics (size, location, number) in 403 healthy human hearts across all age groups. We find that the prevalence of LEs in healthy hearts is far lower than previously reported.
Extracorporeal membrane oxygenation (ECMO) employs vascular cannulation and a gas exchange circuit to provide support to patients with severely compromised cardiopulmonary function. ECMO is often the ...last intervention taken before death and thus presents a unique challenge to medical examiners. This study describes the characteristics of decedents on ECMO at the time of death, including clinical indications, types of circuit configurations, causes and manners of death, gross findings at autopsy, and therapeutic complications. Files of a regional medical examiner office within an academic medical center were searched for the period between 2013 and 2019. Nineteen cases were identified with a median age of 36 years. The circumstances surrounding the initial presentation included: sudden death, trauma, substance abuse, homicide, therapeutic complication, work‐related injury, drowning, and hypothermia. The underlying causes of death included injury‐related, as well as respiratory and cardiac‐related natural diseases. The time spent on ECMO varied from less than 1 h to 10 months. Complications encountered due to ECMO included cannulation site bleeding, pneumohemopericardium, retroperitoneal hematoma, limb ischemia, clotting, and cannula dislodgement. The patient population likely to receive ECMO has significant overlap with death circumstances likely to be reported to the medical examiner. As ECMO therapy has become increasingly available, it is of importance for medical examiners and death investigators to be familiar with the procedure as well as its limitations. Familiarity with ECMO and its sequelae allows for the proper documentation of postmortem findings and fosters an informed determination of the cause and manner of death.
•Semilunar valve fenestrations are common in healthy hearts, but less common than reported in those with cardiovascular disease.•Size and prevalence of semilunar valve fenestrations have no ...demonstrable relationship with age or sex.•Fenestrations are slightly more common and larger in aortic valves when compared with pulmonary valves.
Fenestrations in semilunar valves of human hearts have been incidentally described during autopsies since the 1800s, and were thought to be a degenerative process of the valve cusps. Due to the nature of autopsy, prior literature has primarily examined these fenestrations in pathologic hearts, and has implicated them in leading to valve insufficiency, regurgitation, and cusp rupture. More recent studies have predicted an increase in fenestration prevalence in the rapidly aging United States and have warned of a potential increase in fenestration-related valvular pathology. Herein, we analyze fenestration prevalence in 403 healthy human hearts and report findings that differ from these prior reports, and emphasize that fenestrations may not necessarily portend significant valvular dysfunction.
To determine age-related changes in vestibulo-ocular reflex (VOR) function in community-dwelling adults, and evaluate these for associations with demographic characteristics and cardiovascular risk ...factors.
Cross-sectional analysis within the Baltimore Longitudinal Study of Aging (BLSA), a longitudinal prospective cohort study.
Vestibular testing laboratory within an acute care teaching hospital.
Community-dwelling adults enrolled in the BLSA.
Horizontal VOR gain measurement using video head-impulse testing and visual acuity testing.
VOR gain was calculated as the ratio of eye velocity to head velocity. Demographic and cardiovascular risk factor data were collected through study questionnaires.
One hundred nine subjects were analyzed with mean age (SD) 69.9 years (14.2), with a range from 26 to 92 years. VOR gain remained stable from age 26 to 79 after which it significantly declined at a rate of 0.012/year (p = 0.033) in adjusted analyses. Individuals aged 80 years or older had a nearly 8-fold increased odds of VOR gain less than 0.80 relative to those aged less than 80 years in multivariate models (prevalence of 13.2% vs. 2.8%; OR 7.79, 95% CI: 1.04-58.38). Otherwise, VOR gain did not differ significantly across demographic or cardiovascular risk groups.
We report age-related decline in VOR function in individuals aged 80 years and older. Further analyses are in progress to establish the significance of these VOR abnormalities to functional and mobility outcomes in older individuals.
Cardiac hemangioma is a rare, benign primary tumor characterized by endothelial proliferation. While reports of cardiac hemangiomas demonstrating
F FDG avidity and other forms of hemangiomas showing
...Ga Dotatate avidity have been published, we present a rare case of primary cardiac hemangioma demonstrating
Ga Dotatate avidity, mimicking a primary neuroendocrine tumor.
Zoonotic diseases threaten human health worldwide and are often associated with anthropogenic disturbance. Predicting how disturbance influences spillover risk is critical for effective disease ...intervention but difficult to achieve at fine spatial scales. Here, we develop a method that learns the spatial distribution of a reservoir species from aerial imagery. Our approach uses neural networks to extract features of known or hypothesized importance from images. The spatial distribution of these features is then summarized and linked to spatially explicit reservoir presence/absence data using boosted regression trees. We demonstrate the utility of our method by applying it to the reservoir of Lassa virus, Mastomys natalensis, within the West African nations of Sierra Leone and Guinea. We show that, when trained using reservoir trapping data and publicly available aerial imagery, our framework learns relationships between environmental features and reservoir occurrence and accurately ranks areas according to the likelihood of reservoir presence.
Here, we develop a method that learns the spatial distribution of a reservoir species from aerial imagery. We show that, when trained using reservoir trapping data and publicly available aerial imagery, our framework learns relationships between environmental features and reservoir occurrence and accurately ranks areas according to the likelihood of reservoir presence.
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