SARS-CoV-2 concentrations and virus-laden aerosol size distributions in outdoor air in north and south of Italy.

The COVID-19 disease spread at different rates in the different countries and in different regions of the same country, as happened in Italy. Transmission by contact or at close range due to large respiratory droplets is widely accepted, however, the role of airborne transmission due to small respiratory droplets emitted by infected individuals (also asymptomatic) is controversial. It was suggested that outdoor airborne transmission could play a role in determining the differences observed in the spread rate. Concentrations of virus-laden aerosol are still poorly known and contrasting results are reported, especially for outdoor environments. Here we investigated outdoor concentrations and size distributions of virus-laden aerosol simultaneously collected during the pandemic, in May 2020, in northern (Veneto) and southern (Apulia) regions of Italy. The two regions exhibited significantly different prevalence of COVID-19. Genetic material of SARS-CoV-2 (RNA) was determined, using both real time RT-PCR and ddPCR, in air samples collected using PM10 samplers and cascade impactors able to separate 12 size ranges from nanoparticles (diameter D < 0.056 µm) up to coarse particles (D > 18 µm). Air samples tested negative for the presence of SARS-CoV-2 at both sites, viral particles concentrations were <0.8 copies m-3 in PM10 and <0.4 copies m-3 in each size range investigated. Outdoor air in residential and urban areas was generally not infectious and safe for the public in both northern and southern Italy, with the possible exclusion of very crowded sites. Therefore, it is likely that outdoor airborne transmission does not explain the difference in the spread of COVID-19 observed in the two Italian regions.

Severe atypical hand-foot-and-mouth disease in adults due to coxsackievirus A6: Clinical presentation and phylogenesis of CV-A6 strains.

BACKGROUND: Typically, hand-foot-and-mouth disease (HFMD) is a mild childhood illness associated with coxsackievirus (CV)-A16, CV-A6, enterovirus (EV)-A71. OBJECTIVES: To identify the viral agents associated with severe cases of atypical HFMD in Italy. STUDY DESIGN: Epidemiologically unrelated cases of severe atypical HFMD admitted to the Emergency Room (ER) of IRCCS San Martino IST (Genoa, Italy) in 2014-2016 were investigated. Serologic screening for viral positivity was performed against exanthem-inducing agents. Ten cases with serology indicative of recent EV infection were selected. Molecular assays were used to detect viral genomes in blood [EVs, Parvovirus B19 (PVB19), herpesviruses (CMV; EBV, HHV-6, -7, -8)]. RESULTS: CV-A6 was detected in 10 cases of severe atypical HFMD. Two cases were also infected with PVB19. Herpesviruses were not detected. Phylogenetic analysis mapped the CV-A6 strains into a single cluster related to two recent isolates from a German and an Asian child. Fever, systemic symptoms, severe vasculitis-like rash, and enanthem were predominant at presentation. Spontaneous recovery occurred in 1-3 weeks. CONCLUSIONS: CV-A6 is emerging as a frequent cause of severe atypical HFMD in Italian adults. This viral agent is disseminating worldwide. Dermatologists must identify the manifold alterations caused by EVs and understand the diagnostic power of current virology methods.

Basin-scale analysis of the geomorphic effectiveness of flash floods: A study in the northern Apennines (Italy).

Large floods may produce remarkable channel changes, which determine damages and casualties in inhabited areas. However, our knowledge of such processes remains poor, as is our capability to predict them. This study analyses the geomorphic response of the Nure River (northern Italy) and nine tributaries to a high-magnitude flood that occurred in September 2015. The adopted multi-disciplinary approach encompassed: (i) hydrological and hydraulic analysis; (ii) analysis of sediment delivery to the stream network by means of landslides mapping; (iii) assessment of morphological modifications of the channels, including both channel width and bed elevation changes. The spatial distribution of rainfall showed that the largest rainfall amounts occur in the upper portions of the catchment, with cumulative rainfall reaching 300 mm in 12 h, and recurrence intervals exceeding 100-150 years. The unit peak discharge ranged between 5.2 and 25 m3 s-1 km-2. Channel widening was the most evident effect. In the tributaries, the ratio between post-flood and pre-flood channel width averaged 3.3, with a maximum approaching 20. Widening was associated with channel aggradation up to 1.5 m and removal of riparian vegetation. New islands formed due to the fragmentation of the former floodplain. In the Nure River, the average width ratio was 1.7, and here widening occurred mainly at the expenses of islands. Bed level dynamics in the Nure were varied, including aggradation, incision, and overall stability. The flood geomorphic effectiveness was more pronounced in the middle-higher portions of the basin. Planimetric and elevation changes were well correlated. Regression analysis of the relationship between widening and morphological/ hydraulic controlling factors indicated that unit stream power and confinement index were the most relevant variables. The study provides useful insights for river management, especially with regard to the proportion of the valley floor subject to erosion and/or deposition during large events.

The Possible Combined Action of Different Trigger Agents in Rosacea / Posible acción combinada de los diferentes agentes desencadenantes en la rosácea

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