A spatially distributed model for the dynamic prediction of sediment erosion and transport in mountainous forested watersheds

Erosion and sediment transport in a temperate forested watershed are predicted with a new sediment model that represents the main sources of sediment generation in forested environments (mass wasting, hillslope erosion, and road surface erosion) within the distributed hydrology-soil-vegetation model (DHSVM) environment. The model produces slope failures on the basis of a factor-of-safety analysis with the infinite slope model through use of stochastically generated soil and vegetation parameters. Failed material is routed downslope with a rule-based scheme that determines sediment delivery to streams. Sediment from hillslopes and road surfaces is also transported to the channel network. A simple channel routing scheme is implemented to predict basin sediment yield. We demonstrate through an initial application of this model to the Rainy Creek catchment, a tributary of the Wenatchee River, which drains the east slopes of the Cascade Mountains, that the model produces plausible sediment yield and ratios of landsliding and surface erosion when compared to published rates for similar catchments in the Pacific Northwest. A road removal scenario and a basin-wide fire scenario are both evaluated with the model

Hepatitis C: global epidemiology and strategies for control

It is estimated that globally there are approximately 100 million persons with serological evidence of current or past HCV infection, and that HCV causes about 700 000 deaths each year. The prevalence of infection is the highest in lower and middle income countries, in which a significant number of past infections were caused by iatrogenic transmission and sub-optimal injection safety. In contrast, in developed countries, infections are caused mainly by high-risk exposures and behaviours among specific populations, such as persons who inject drugs. Recently, new direct antiviral activity (DAA) oral drugs with high rates of cure over short duration, which are well tolerated, have made chronic hepatitis C a curable condition. The extraordinary clinical performance of DAAs and recent substantial price reductions and expansion in access in resource-limited settings has provided new impetus for potential control and elimination of hepatitis C as a public health threat. We review the global epidemiology of HCV and the opportunities for preventative and treatment interventions to achieve global control of HCV infection. We also summarize the key elements of the World Health Organization's first-ever global health sector strategy for addressing the viral hepatitis pandemic

Is there sufficient evidence to repeal three decades of clinical research on chronic hepatitis C?

Introduction A recently published systematic review on the treatment of chronic hepatitis C (CHC) with direct-acting antivirals (DAAs) performed by the Cochrane Collaboration has reached highly controversial conclusions [1,2]. The authors included 138 randomized controlled trials (RCTs) with no restriction on disease stage or type of DAA combination. They concluded that there was no evidence to either confirm or reject the premise that DAAs had any clinical effect, and they also stated that sustained virologic response (SVR) was an unreliable surrogate marker to assess clinical efficacy. We differ on both these counts. These results are in discordance with current international guidelines (https://www.hcvguidelines.org/) [3], the opinion of the of scientific societies for the study of liver diseases in Europe [4] and in America (https://www.aasld.org/about-aasld/press-room/aasld-expresses-concern-cochrane-review-daas), and the endorsement of the World Health Organization, which states that DAAs may eliminate hepatitis C virus (HCV) by 2030 (http://apps.who.int/iris/bitstream/10665/246177/1/WHO-HIV-2016.06-eng.pdf?ua=1; http://www.who.int/hepatitis/news-events/direct-acting-antiviral-cure-hepatitis-c/en/) [5]. The Cochrane Collaboration's results reflect an underestimation of the actual value of observational evidence in the context of the current knowledge of CHC clinical management [6,7]

Inspiratory muscle workload due to dynamic intrinsic PEEP in stable COPD patients: effects of two different settings of non-invasive pressure-support ventilation.

BACKGROUND: In severe stable hypercapnic COPD patients the amount of pressure time product (PTP) spent to counterbalance their dynamic intrinsic positive end expiratory pressure (PEEPi,dyn) is high: no data are available on the best setting of non invasive pressure support ventilation (NPSV) to reduce the inspiratory muscle workload due to PEEPi,dyn. METHODS: The objectives of this randomised controlled physiological study were: 1. To measure the inspiratory muscle workload due to PEEPi,dyn 2. To measure the effects on this parameter of two settings of NPSV in stable COPD patients with chronic hypercapnia admitted in a Pulmonary Division of two Rehabilitation Centers. Twenty-three stable COPD patients with chronic hypercapnia on domiciliary nocturnal NPSV for 30 +/- 20 months were submitted to an evaluation of breathing pattern, PEEPi,dyn, inspiratory muscle workload and its partitioning during both assisted and unassisted ventilation. Two settings of NPSV were randomly applied for 30 minutes each: i- "at patient's comfort" (C): Inspiratory pressure support (IPS) was the maximal tolerated pressure able to reduce awake PaCO2 with the addition of a pre-set level of external PEEP (PEEPe); ii- "physiological setting" (PH): the level of IPS able to achieve a > 40% and < 90% decrease in transdiaphragmatic pressure in comparison to spontaneous breathing (SB). A PEEPe level able to reduce PEEPi,dyn by at least 50% was added. RESULTS: During SB the tidal diaphragmatic pressure-time product (PTPdi/b) was 17.62 +/- 7.22 cmH2O*sec, the component due to PEEPi,dyn (PTPdiPEEPi,dyn) being 38 +/- 17% (range: 16-65%). Compared to SB,PTPdiPEEPi,dyn was reduced significantly with both settings, the reduction being greater with PH compared to C. CONCLUSIONS: In conclusion in severe COPD patients with chronic hypercapnia the inspiratory muscle workload due to PEEPidyn is high and is reduced by NPSV at a greater extent when ventilator setting is tailored to patient's mechanics

Early improvement of glycaemic control after virus clearance in patients with chronic hepatitis C and severe liver fibrosis: a cohort study

HCV has been recognized as the cause of chronic hepatitis C (CHC) since 1990. CHC is associated with progressive liver damage and extrahepatic conditions. Direct antiviral agents (DAAs), approved in 2014, have shown effectiveness in eradicating HCV in most patients. However, little is known about the effect of viral eradication on hepatic and extra-hepatic damage. We performed a historical cohort study of patients with HCV-related liver diseases who achieved SVR from March 2015 to October 2016 at INMI Lazzaro Spallanzani liver Unit in Rome (Italy). Repeated measures of glycaemia were analysed through a multilevel analysis framework to assess short time kinetics of blood glucose level at different times after therapy and for different levels of HCV viremia. The analysis included 205 patients. A model assessing temporal kinetics and variation of glycaemia according to HCV viremia provided evidence that blood glucose levels significantly dropped in patients with diabetes achieving SVR. Most of the variations occurred at 3-5 weeks of therapy (-17.96 mg/dL; p<0.001) and in coincidence with HCV clearance (-13.92 mg/dL; p<0.001). A weak, non-statistically significant reduction was observed in normoglycemic patients. Our study provides evidence that DAAs therapy may significantly improve glycaemic control in patients with CHC achieving SVR even when liver diseases are already established

Spatial modes for transmission of chikungunya virus during a large chikungunya outbreak in Italy: a modeling analysis

14openInternationalBothBackground The spatial spread of many mosquito-borne diseases occurs by focal spread at the scale of a few hundred meters and over longer distances due to human mobility. The relative contributions of different spatial scales for transmission of chikungunya virus require definition to improve outbreak vector control recommendations. Methods We analyzed data from a large chikungunya outbreak mediated by the mosquito Aedes albopictus in the Lazio region, Italy, consisting of 414 reported human cases between June and November 2017. Using dates of symptom onset, geographic coordinates of residence, and information from epidemiological questionnaires, we reconstructed transmission chains related to that outbreak. Results Focal spread (within 1 km) accounted for 54.9% of all cases, 15.8% were transmitted at a local scale (1–15 km) and the remaining 29.3% were exported from the main areas of chikungunya circulation in Lazio to longer distances such as Rome and other geographical areas. Seventy percent of focal infections (corresponding to 38% of the total 414 cases) were transmitted within a distance of 200 m (the buffer distance adopted by the national guidelines for insecticide spraying). Two main epidemic clusters were identified, with a radius expanding at a rate of 300–600 m per month. The majority of exported cases resulted in either sporadic or no further transmission in the region. Conclusions Evidence suggest that human mobility contributes to seeding a relevant number of secondary cases and new foci of transmission over several kilometers. Reactive vector control based on current guidelines might allow a significant number of secondary clusters in untreated areas, especially if the outbreak is not detected early. Existing policies and guidelines for control during outbreaks should recommend the prioritization of preventive measures in neighboring territories with known mobility flows to the main areas of transmission.openGuzzetta, Giorgio; Vairo, Francesco; Mammone, Alessia; Lanini, Simone; Poletti, Piero; Manica, Mattia; Rosa, Roberto; Caputo, Beniamino; Solimini, Angelo; Torre, Alessandra Della; Scognamiglio, Paola; Zumla, Alimuddin; Ippolito, Giuseppe; Merler, StefanoGuzzetta, G.; Vairo, F.; Mammone, A.; Lanini, S.; Poletti, P.; Manica, M.; Rosa, R.; Caputo, B.; Solimini, A.; Torre, A.D.; Scognamiglio, P.; Zumla, A.; Ippolito, G.; Merler, S

Spatial modes for transmission of chikungunya virus during a large chikungunya outbreak in Italy. A modeling analysis

Background The spatial spread of many mosquito-borne diseases occurs by focal spread at the scale of a few hundred meters and over longer distances due to human mobility. The relative contributions of different spatial scales for transmission of chikungunya virus require definition to improve outbreak vector control recommendations. Methods We analyzed data from a large chikungunya outbreak mediated by the mosquito Aedes albopictus in the Lazio region, Italy, consisting of 414 reported human cases between June and November 2017. Using dates of symptom onset, geographic coordinates of residence, and information from epidemiological questionnaires, we reconstructed transmission chains related to that outbreak. Results Focal spread (within 1 km) accounted for 54.9% of all cases, 15.8% were transmitted at a local scale (1–15 km) and the remaining 29.3% were exported from the main areas of chikungunya circulation in Lazio to longer distances such as Rome and other geographical areas. Seventy percent of focal infections (corresponding to 38% of the total 414 cases) were transmitted within a distance of 200 m (the buffer distance adopted by the national guidelines for insecticide spraying). Two main epidemic clusters were identified, with a radius expanding at a rate of 300–600 m per month. The majority of exported cases resulted in either sporadic or no further transmission in the region. Conclusions Evidence suggest that human mobility contributes to seeding a relevant number of secondary cases and new foci of transmission over several kilometers. Reactive vector control based on current guidelines might allow a significant number of secondary clusters in untreated areas, especially if the outbreak is not detected early. Existing policies and guidelines for control during outbreaks should recommend the prioritization of preventive measures in neighboring territories with known mobility flows to the main areas of transmission

Detection of Viral RNA in Tissues following Plasma Clearance from an Ebola Virus Infected Patient

An unprecedented Ebola virus (EBOV) epidemic occurred in 2013–2016 in West Africa. Over this time the epidemic exponentially grew and moved to Europe and North America, with several imported cases and many Health Care Workers (HCW) infected. Better understanding of EBOV infection patterns in different body compartments is mandatory to develop new countermeasures, as well as to fully comprehend the pathways of human-to-human transmission. We have longitudinally explored the persistence of EBOV-specific negative sense genomic RNA (neg-RNA) and the presence of positive sense RNA (pos-RNA), including both replication intermediate (antigenomic-RNA) and messenger RNA (mRNA) molecules, in the upper and lower respiratory tract, as compared to plasma, in a HCW infected with EBOV in Sierra Leone, who was hospitalized in the high isolation facility of the National Institute for Infectious Diseases “Lazzaro Spallanzani” (INMI), Rome, Italy. We observed persistence of pos-RNA and neg-RNAs in longitudinally collected specimens of the lower respiratory tract, even after viral clearance from plasma, suggesting possible local replication. The purpose of the present study is to enhance the knowledge on the biological features of EBOV that can contribute to the human-to-human transmissibility and to develop effective intervention strategies. However, further investigation is needed in order to better understand the clinical meaning of viral replication and shedding in the respiratory tract