Andrea Malizia

Ebola Virus Disease 2013-2014 Outbreak in West Africa: An Analysis of the Epidemic Spread and Response

The Ebola virus epidemic burst in West Africa in late 2013, started in Guinea, reached in a few months an alarming diffusion, actually involving several countries (Liberia, Sierra Leone, Nigeria, Senegal, and Mali). Guinea and Liberia, the first nations affected by the outbreak, have put in place measures to contain the spread, supported by international organizations; then they were followed by the other nations affected. In the present EVD outbreak, the geographical spread of the virus has followed a new route: the achievement of large urban areas at an early stage of the epidemic has led to an unprecedented diffusion, featuring the largest outbreak of EVD of all time. This has caused significant concerns all over the world: the potential reaching of far countries from endemic areas, mainly through fast transports, induced several countries to issue information documents and health supervision for individuals going to or coming from the areas at risk. In this paper the geographical spread of the epidemic was analyzed, assessing the sequential appearance of cases by geographic area, considering the increase in cases and mortality according to affected nations. The measures implemented by each government and international organizations to contain the outbreak, and their effectiveness, were also evaluated.

STARDUST experimental campaign and numerical simulations: influence of obstacles and temperature on dust resuspension in a vacuum vessel under LOVA

Activated dust mobilization during a Loss of Vacuum Accident (LOVA) is one of the safety concerns for the International Thermonuclear Experimental Reactor (ITER). Intense thermal loads in fusion devices occur during plasma disruptions, edge localized modes and vertical displacement events. They will result in macroscopic erosion of the plasma facing materials and consequent accumulation of activated dust into the ITER vacuum vessel (VV). These kinds of events can cause dust leakage outside the VV that represents a high radiological risk for the workers and the population. A small facility, Small Tank for Aerosol Removal and Dust (STARDUST), was set up at the ENEA Frascati laboratories to perform experiments concerning the dust mobilization in a volume with the initial conditions similar to those existing in ITER VV. The aim of this work was to reproduce a low pressurization rate (300?Pa?s?1) LOVA event in a VV due to a small air leakage for two different positions of the leak, at the equatorial port level and at the divertor port level, in order to evaluate the influence of obstacles and walls temperature on dust resuspension during both maintenance (MC) and accident conditions (AC) (Twalls = 25??C MC, 110??C AC). The dusts used were tungsten (W), stainless steel 316 (SS316) and carbon (C), similar to those produced inside the vacuum chamber in a fusion reactor when the plasma facing materials vaporize due to the high energy deposition. The experimental campaign has been carried out by introducing inside STARDUST facility an obstacle to simulate the presence of objects, such as divertor. In the obstacle a slit was cut to simulate the limiter?divertor gap inside ITER VV. In this paper experimental campaign results are shown in order to investigate how the divertor and limiter?divertor gap influence dust mobilization into a VV. A two-dimensional (2D) modelling of STARDUST was made using the CFD commercial code FLUENT, in order to get a preliminary overview of the fluid dynamics behaviour during a LOVA event and to justify the mobilization data. In addition, a numerical model was developed to compare numerical results with experimental ones.

Viral bioterrorism: Learning the lesson of Ebola virus in West Africa 2013-2015.

Among the potential biological agents suitable as a weapon, Ebola virus represents a major concern. Classified by the CDC as a category A biological agent, Ebola virus causes severe hemorrhagic fever, characterized by high case-fatality rate; to date, no vaccine or approved therapy is available. The EVD epidemic, which broke out in West Africa since the late 2013, has got the issue of the possible use of Ebola virus as biological warfare agent (BWA) to come to the fore once again. In fact, due to its high case-fatality rate, population currently associates this pathogen to a real and tangible threat. Therefore, its use as biological agent by terrorist groups with offensive purpose could have serious repercussions from a psychosocial point of view as well as on closely sanitary level. In this paper, after an initial study of the main characteristics of Ebola virus, its potential as a BWA was evaluated. Furthermore, given the spread of the epidemic in West Africa in 2014 and 2015, the potential dissemination of the virus from an urban setting was evaluated. Finally, it was considered the actual possibility to use this agent as BWA in different scenarios, and the potential effects on one or more nations stability.

Biological emergency management: The case of ebola 2014 and the air transportation involvement

The putative spread after the outbreak of the haemorrhagic fever epidemic caused by Ebola virus in West Africa, in the early months of 2014, puts the spotlight on the management of biological risks involving air transportation. Ebola virus is a highly pathogenic agent, causing a haemorrhagic fever defined Ebola HF, characterized by a high fatality. This virus is generally considered to be self-limiting in terms of diffusion; its lethality is in fact so high as to prevent the exit from rural areas where outbreaks generally occur. However, when the virus comes from rural areas and reaches urban places, it is important to assess the risk of spreading even in areas far from the outbreak of origin. Therefore, the development or strengthening of strategies and plans to take action with timely and effective response in order to reduce the consequences of public health emergencies is paramount. During Ebola virus outbreak in West Africa in 2014, World Health Organization focused attention on many airports, stops of main flights coming from Africa; the aviation, due to its nature, has the potential to help boost the global spread of transmissible diseases, since air travel allow to reach the most remote locations in hours. The management of biological emergencies during ordinary operations of airlines and airports represents a real constraint in the event of contrast epidemic situations or endemic outbreaks. An effective response plan should include a careful assessment of the risks and the establishment of procedures to carry on board of aircrafts or on the ground. To ensure that this complex system works correctly, a broad and effective cooperation between the different actors involved is required. On the international level, several documents and recommendations relating to the management of contagious diseases in aeronautical environment have been produced by authoritative agencies. In this paper, after an overview on the international response to public health emergencies in the aviation environment, the attention is focused on emergency response to the Ebola virus crisis in 2014, including an evaluation of the potential dispersion of the pathogen.

Use of particle counter system for the optimization of sampling ,identification and decontamination procedures for biological aerosols dispersion in confined environment

In a CBRNe (Chemical, Biological, Radiological, Nuclear and explosive) scenario, biological agents hardly allow efficient detection/identification because of the incubation time that provides a lag in symptoms outbreak following their dissemination. The detection of atmospheric dispersion of biological agents (i.e.: toxins, viruses, bacteria and so on) is a key issue for the safety of people and security of environment. Another fundamental aspect is related to the efficiency of the sampling method which leads to the identification of the agent released; in fact an effective sampling method is needed either to identify the contamination and to check for the decontamination procedure. Environmental monitoring is one of the ways to improve fast detection of biological agents; for instance, particle counters with the ability of discriminating between biological and non-biological particles are used for a first warning when the amount of biological particles exceeds a particular threshold. Nevertheless, these systems are not able to distinguish between pathogen and non-pathogen organisms, thus, classical “laboratory” assays are still required to unambiguously identify the particle which triggered the warning signal. In this work, a combination of commercially available equipment for detection and identification of the atmospheric dispersion of biological agents was evaluated in partnership between the Italian Army, the Department of Industrial Engineering and the School of Medicine and Surgery of the University of Rome “Tor Vergata”. The aim of this work, whose results are presented here, was to conduce preliminary studies on the dynamics of biological aerosols fallout after its dispersion, to improve detection, sampling and identification techniques. This will help minimizing the impact of the release of biological agents and guarantee environmental and people safety and security.

Safety Analysis in Large Volume Vacuum Systems Like Tokamak: Experiments and Numerical Simulation to Analyze Vacuum Ruptures Consequences

The large volume vacuum systems are used in many industrial operations and research laboratories. Accidents in these systems should have a relevant economical and safety impact. A loss of vacuum accident (LOVA) due to a failure of the main vacuum vessel can result in a fast pressurization of the vessel and consequent mobilization dispersion of hazardous internal material through the braches. It is clear that the influence of flow fields, consequence of accidents like LOVA, on dust resuspension is a key safety issue. In order to develop this analysis an experimental facility is been developed: STARDUST. This last facility has been used to improve the knowledge about LOVA to replicate a condition more similar to appropriate operative condition like to kamaks. By the experimental data the boundary conditions have been extrapolated to give the proper input for the 2D thermofluid-dynamics numerical simulations, developed by the commercial CFD numerical code. The benchmark of numerical simulation results with the experimental ones has been used to validate and tune the 2D thermofluid-dynamics numerical model that has been developed by the authors to replicate the LOVA conditions inside STARDUST. In present work, the facility, materials, numerical model, and relevant results will be presented.

UMEL: A new regression tool to identify measurement peaks in LIDAR/DIAL systems for environmental physics applications

Recently, surveying large areas in an automatic way, for early detection of both harmful chemical agents and forest fires, has become a strategic objective of defence and public health organisations. The Lidar and Dial techniques are widely recognized as a cost-effective alternative to monitor large portions of the atmosphere. To maximize the effectiveness of the measurements and to guarantee reliable monitoring of large areas, new data analysis techniques are required. In this paper, an original tool, the Universal Multi Event Locator, is applied to the problem of automatically identifying the time location of peaks in Lidar and Dial measurements for environmental physics applications. This analysis technique improves various aspects of the measurements, ranging from the resilience to drift in the laser sources to the increase of the system sensitivity. The method is also fully general, purely software, and can therefore be applied to a large variety of problems without any additional cost. The potential of the proposed technique is exemplified with the help of data of various instruments acquired during several experimental campaigns in the field.

Raman water vapour concentration measurements for reduction of false alarms in forest fire detection

Forest fires can be the cause of environmental catastrophe, with the natural outcomes of serious ecological and economic damages, together with the possibility to endanger human safety. At the aim to reduce this catastrophe several author have been shown that the Laser light scattering can be uses to reveals the particulate emitted in the smoke. Infact experimental and theoretical investigations have shown that lidar is a powerful tool to detect the tenuous smoke plumes produced by forest fires at an early stage. In early 90s Arbolino and Andreucci have shown the theoretical possibility to detect the particulate emitted in atmosphere from smoke forest fire. Vilar at all have shown experimentally the possibility to measure the density variation in atmosphere due to plume emitted in forest fire event. Gaudio at all. have already shown that it is possible to evaluate water vapor emitted in smoke of vegetable fuel using a CO2 dial system. In this paper a theoretical model to evaluate the capabilities of a lidar system in fire surveillance of wooded areas will be presented. In particular we intend propose a technique to minimizing the false alarm in the detection of forest fire by lidar based on a measurement of second components emitted in a combustion process. Usually to detect a fire alarm a rapid increase of aerosol amount is measured. If the backscattering signal report a peak, the presences of a forest fire will be probable. Our idea to confirm this hypothesis is measure the second components emitted in a forest fire at the aim to minimize the false alarm. The simulated measurements of the humidity amount within the smoke plume will be carried out by means of Raman analysis. Fixing the burning rate of the vegetable-fuels, the maximum range of detection will be evaluated.

Numerical simulations as tool to predict chemical and radiological hazardous diffusion in case of nonconventional events

CFD (Computational Fluid Dynamics) simulations are widely used nowadays to predict the behaviour of fluids in pure research and in industrial applications. This approach makes it possible to get quantitatively meaningful results, often in good agreement with the experimental ones. The aim of this paper is to show how CFD calculations can help to understand the time evolution of two possible CBRNe (Chemical-Biological-Radiological-Nuclear-explosive) events: (1) hazardous dust mobilization due to the interaction between a jet of air and a metallic powder in case of a LOVA (Loss Of Vacuum Accidents) that is one of the possible accidents that can occur in experimental nuclear fusion plants; (2) toxic gas release in atmosphere. The scenario analysed in the paper has consequences similar to those expected in case of a release of dangerous substances (chemical or radioactive) in enclosed or open environment during nonconventional events (like accidents or man-made or natural disasters).

Application of Real-Time PCR to Identify Residual Bio-Decontamination of Confined Environments after Hydrogen Peroxide Vapor Treatment: Preliminary Results

This study was conducted to assess the effectiveness of Hydrogen Peroxide Vapor (HPV) to remove biological contamination in a confined environment and to evaluate real-time PCR assay as a technique for the evaluation of the decontamination efficiency. Decontamination after the dispersion of biological aerosol is a main issue from a civilian, public health and military perspective. Despite the effectiveness of aggressive substances, eco-friendly but still efficient methods for decontamination are a relevant demand and Hydrogen Peroxide Vapor (HPV) is among the most recent and promising technologies in this field. Another related issue is: when an environment can be considered fully decontaminated? The answer clearly depends on the objectives of the decontamination and this will affect the choice of the methodology. Furthermore, classical microbiological and molecular biology techniques are commonly used to identify biological contamination and residual contamination, but many of them are time consuming and require advanced training for the operators who perform the analysis. This may represent a bottleneck, especially when a quick response to an emergency is needed (i.e. during an unconventional event like CBRNe ones). In this work, a combination of commercially available equipment for detection, identification and decontamination, was evaluated in partnership between the Italian Army, the Department of Industrial Engineering and the School of Medicine and Surgery of the University of Rome “Tor Vergata”. The purpose of this work was to find a setup for equipment and methodologies for detection, identification and decontamination, to implement in case of biological events. Preliminary results show that, despite the death of the microorganisms, nucleic acids are not completely degraded by HPV treatment and, as a consequence, that real-time PCR may be the adequate, quick and easy method to verify the efficiency of bio decontamination when nucleic acid degradation represent the final objective.