Accident Management under Extreme Events

Most nuclear power plants have extensive sets of Emergency Operating Procedures and Severe Accident Management Guidelines. These offer protection for a large series of events, both inside and outside the licensed design basis of the plant. For Extreme Events, which are characterised by a large destruction on-site and may include loss of command and control, damage to multiple units on-site, loss of communication both on-site and to off-site centres, staff members wounded or killed, such protection may not be enough. Examples of Extreme Events are air plane crash, site flooding, large earthquake plus possible tsunamis, etc. This paper describes what additional procedures, guidelines, hardware and organisational issues are needed to protect a site against such events. It is based on lessons learned from large destructive events in the past, such as the 9/11 attacks in the USA in 2001 and the tsunami at the Fukushima-Daiichi plants in 2011

Accident Management under Extreme Events

Most nuclear power plants have extensive sets of Emergency Operating Procedures and Severe Accident Management Guidelines. These offer protection for a large series of events, both inside and outside the licensed design basis of the plant. For Extreme Events, which are characterised by a large destruction on-site and may include loss of command and control, damage to multiple units on-site, loss of communication both on-site and to off-site centres, staff members wounded or killed, such protection may not be enough. Examples of Extreme Events are air plane crash, site flooding, large earthquake plus possible tsunamis, etc. This paper describes what additional procedures, guidelines, hardware and organisational issues are needed to protect a site against such events. It is based on lessons learned from large destructive events in the past, such as the 9/11 attacks in the USA in 2001 and the tsunami at the Fukushima-Daiichi plants in 2011

Upscaling the surveillance of tick-borne pathogens in the French Caribbean Islands

Despite the high burden of vector-borne disease in (sub)tropical areas, few information are available regarding the diversity of tick and tick-borne pathogens circulating in the Caribbean. Management and control of vector-borne disease require actual epidemiological data to better assess and anticipate the risk of (re)emergence of tick-borne diseases in the region. To simplify and reduce the costs of such large-scale surveys, we implemented a high-throughput microfluidic real-time PCR system suitable for the screening of the main bacterial and parasitic genera involved in tick-borne disease and potentially circulating in the area. We used the new screening tool to perform an exploratory epidemiological study on 132 adult specimens of Amblyomma variegatum and 446 of Rhipicephalus microplus collected in Guadeloupe and Martinique. Not only the system was able to detect the main pathogens of the area—Ehrlichia ruminantium, Rickettsia africae, Anaplasma marginale, Babesia bigemina and Babesia bovis—but the system also provided evidence of unsuspected microorganisms in Caribbean ticks, belonging to the Anaplasma, Ehrlichia, Borrelia and Leishmania genera. Our study demonstrated how high-throughput microfluidic real-time PCR technology can assist large-scale epidemiological studies, providing a rapid overview of tick-borne pathogen and microorganism diversity, and opening up new research perspectives for the epidemiology of tick-borne pathogens

European Network for Neglected Vectors and Vector-Borne Infections COST Action Guidelines: What Is This About and What Is This For?

European network for neglected vectors and vector-borne infections COST action guidelines: What Is this about and what iIs this For

Are Bartonella species tick-borne pathogens ?

Les bactéries du genre Bartonella infectent un très grand nombre d’espèces de mammifères y compris l’Homme au sein desquelles elle est transmise par le biais de la piqûre d’un arthropode hématophage. Les tiques sont les premiers vecteurs d’agents pathogènes en Europe et de nombreuses études ont suggéré leur rôle dans la transmission de certaines espèces de Bartonella. Chez l’Homme, les symptômes causés par l’infection par Bartonella sont très divers et dépendent de l’espèce incriminée et de l’état immunitaire de la personne infectée. Dans l’étude présentée ici nous avons isolé des espèces de Bartonella d’origine animale chez des patients souffrant de symptômes chroniques non spécifiques dont l’apparition était consécutive à une piqûre de tiques. Parmi ces espèces certaines n’avaient jamais été isolées chez l’homme.Bacteria of the genus Bartonella infect a large number of species of mammals including humans through the bite of blood-sucking arthropod. Ticks are the primary vectors of pathogens in Europe and many studies have suggested their role in the transmission of certain species of Bartonella to humans or animals. In humans, the symptoms caused by Bartonella infection are diverse and depend on the species and the immune status of the infected person. In the present study, we isolated in patients suffering from chronic non-specific symptoms secondary to tick bites animal specific Bartonella spp. Some of these had never been isolated from humans so far

Borrelia Diversity and Co-infection with Other Tick Borne Pathogens in Ticks

Identifying Borrelia burgdorferi as the causative agent of Lyme disease in 1981 was a watershed moment in understanding the major impact that tick-borne zoonoses can have on public health worldwide, particularly in Europe and the USA. The medical importance of tick-borne diseases has long since been acknowledged, yet little is known regarding the occurrence of emerging tick-borne pathogens such as Borrelia spp., Anaplasma phagocytophilum, Rickettsia spp., Bartonella spp., "Candidatus Neoehrlichia mikurensis", and tick-borne encephalitis virus in questing ticks in Romania, a gateway into Europe. The objective of our study was to identify the infection and co-infection rates of different Borrelia genospecies along with other tick-borne pathogens in questing ticks collected from three geographically distinct areas in eastern Romania. We collected 557 questing adult and nymph ticks of three different species (534 Ixodes ricinus, 19 Haemaphysalis punctata, and 4 Dermacentor reticulatus) from three areas in Romania. We analyzed ticks individually for the presence of eight different Borrelia genospecies with high-throughput real-time PCR. Ticks with Borrelia were then tested for possible co-infections with A. phagocytophilum, Rickettsia spp., Bartonella spp., "Candidatus Neoehrlichia mikurensis", and tick-borne encephalitis virus. Borrelia spp. was detected in I. ricinus ticks from all sampling areas, with global prevalence rates of 25.8%. All eight Borrelia genospecies were detected in I. ricinus ticks: Borrelia garinii (14.8%), B. afzelii (8.8%), B. valaisiana (5.1%), B. lusitaniae (4.9%), B. miyamotoi (0.9%), B. burgdorferi s. s (0.4%), and B. bissettii (0.2%). Regarding pathogen co-infection 64.5% of infected I. ricinus were positive for more than one pathogen. Associations between different Borrelia genospecies were detected in 9.7% of ticks, and 6.9% of I. ricinus ticks tested positive for co-infection of Borrelia spp. with other tick-borne pathogens. The most common association was between B. garinii and B. afzelii (4.3%), followed by B. garinii and B. lusitaniae (3.0%). The most frequent dual co-infections were between Borrelia spp. and Rickettsia spp., (1.3%), and between Borrelia spp. and "Candidatus Neoehrlichia mikurensis" (1.3%). The diversity of tick-borne pathogens detected in this study and the frequency of co-infections should influence all infection risk evaluations following a tick bite

Vector Competence of the Tick Ixodes ricinus for Transmission of Bartonella birtlesii

Bartonella spp. are facultative intracellular vector-borne bacteria associated with several emerging diseases in humans and animals all over the world. The potential for involvement of ticks in transmission of Bartonella spp. has been heartily debated for many years. However, most of the data supporting bartonellae transmission by ticks come from molecular and serological epidemiological surveys in humans and animals providing only indirect evidences without a direct proof of tick vector competence for transmission of bartonellae. We used a murine model to assess the vector competence of Ixodes ricinus for Bartonella birtlesii. Larval and nymphal I. ricinus were fed on a B. birtlesii-infected mouse. The nymphs successfully transmitted B. birtlesii to naïve mice as bacteria were recovered from both the mouse blood and liver at seven and 16 days after tick bites. The female adults successfully emitted the bacteria into uninfected blood after three or more days of tick attachment, when fed via membrane feeding system. Histochemical staining showed the presence of bacteria in salivary glands and muscle tissues of partially engorged adult ticks, which had molted from the infected nymphs. These results confirm the vector competence of I. ricinus for B. birtlesii and represent the first in vivo demonstration of a Bartonella sp. transmission by ticks. Consequently, bartonelloses should be now included in the differential diagnosis for patients exposed to tick bites

Taxon Appearance From Extraction and Amplification Steps Demonstrates the Value of Multiple Controls in Tick Microbiota Analysis

Background: The development of high-throughput sequencing technologies has substantially improved analysis of bacterial community diversity, composition, and functions. Over the last decade, high-throughput sequencing has been used extensively to identify the diversity and composition of tick microbial communities. However, a growing number of studies are warning about the impact of contamination brought along the different steps of the analytical process, from DNA extraction to amplification. In low biomass samples, e.g., individual tick samples, these contaminants may represent a large part of the obtained sequences, and thus generate considerable errors in downstream analyses and in the interpretation of results. Most studies of tick microbiota either do not mention the inclusion of controls during the DNA extraction or amplification steps, or consider the lack of an electrophoresis signal as an absence of contamination. In this context, we aimed to assess the proportion of contaminant sequences resulting from these steps. We analyzed the microbiota of individual Ixodes ricinus ticks by including several categories of controls throughout the analytical process: homogenization, DNA extraction, and DNA amplification. Results: Controls yielded a significant number of sequences (1, 126–13, 198 mean sequences, depending on the control category). Some operational taxonomic units (OTUs) detected in these controls belong to genera reported in previous tick microbiota studies. In this study, these OTUs accounted for 50.9% of the total number of sequences in our samples, and were considered contaminants. Contamination levels (i.e., the percentage of sequences belonging to OTUs identified as contaminants) varied with tick instar and sex: 76.3% of nymphs and 75% of males demonstrated contamination over 50%, while most females (65.7%) had rates lower than 20%. Contamination mainly corresponded to OTUs detected in homogenization and extraction reagent controls, highlighting the importance of carefully controlling these steps. Conclusion: Here, we showed that contaminant OTUs from sample laboratory processing steps can represent more than half the total sequence yield in sequencing runs, and lead to unreliable results when characterizing tick microbial communities. We thus strongly advise the routine use of negative controls in tick microbiota studies, and more generally in studies involving low biomass samples