Evaluating the impact of hydrometeorological conditions on E. coli concentration in farmed mussels and clams: experience in Central Italy.

Highly populated coastal environments receive large quantities of treated and untreated wastewater from human and industrial sources. Bivalve molluscs accumulate and retain contaminants, and their analysis provides evidence of past contamination. Rivers and precipitation are major routes of bacteriological pollution from surface or sub-surface runoff flowing into coastal areas. However, relationships between runoff, precipitation, and bacterial contamination are site-specific and dependent on the physiographical characteristics of each catchment. In this work, we evaluated the influence of precipitation and river discharge on molluscs' Escherichia coli concentrations at three sites in Central Italy, aiming at quantifying how hydrometeorological conditions affect bacteriological contamination of selected bivalve production areas. Rank-order correlation analysis indicated a stronger association between E. coli concentrations and the modelled Pescara River discharge maxima (r = 0.69) than between E. coli concentration and rainfall maxima (r = 0.35). Discharge peaks from the Pescara River caused an increase in E. coli concentration in bivalves in 87% of cases, provided that the runoff peak occurred 1-6 days prior to the sampling date. Precipitation in coastal area was linked to almost 60% of cases of E. coli high concentrations and may enhance bacterial transportation offshore, when associated with a larger-scale weather system, which causes overflow occurrence.

Avian influenza A (H5N1) outbreaks in different poultry farm types in Egypt: the effect of vaccination, closing status and farm size.

BACKGROUND: The Avian Influenza A (H5N1) virus is endemic in poultry in Egypt. The winter of 2014/2015 was particularly worrying as new clusters of HPAI A (H5N1) virus emerged, leading to an important number of AI A (H5N1) outbreaks in poultry farms and sporadic human cases. To date, few studies have investigated the distribution of HPAI A (H5N1) outbreaks in Egypt in relation to protective / risk factors at the farm level, a gap we intend to fill. The aim of the study was to analyse passive surveillance data that were based on observation of sudden and high mortality of poultry or drop in duck or chicken egg production, as a basis to better understand and discuss the risk of HPAI A (H5N1) presence at the farm level in large parts of the Nile Delta. RESULTS: The probability of HPAI A (H5N1) presence was associated with several characteristics of the farms. Vaccination status, absence of windows/openings in the farm and the number of birds per cycle of production were found to be protective factors, whereas the presence of a duck farm with significant mortality or drop in egg production in the village was found to be a risk factor. CONCLUSIONS: Results demonstrate the key role of several prevention and biosecurity measures to reduce HPAI A (H5N1) virus circulation, which could promote better poultry farm biosecurity in Egypt.

Outbreak of unusual Salmonella enterica serovar Typhimurium monophasic variant 1,4 [5],12:i:-, Italy, June 2013 to September 2014.

Monophasic variant of Salmonella enterica subspecies enterica serovar Typhimurium (monophasic S. Typhimurium), with antigenic structure 1,4,[5],12:i:-, appears to be of increasing importance in Europe. In Italy, monophasic S. Typhimurium represented the third most frequent Salmonella serovar isolated from human cases between 2004 and 2008. From June 2013 to October 2014, a total of 206 human cases of salmonellosis were identified in Abruzzo region (Central Italy). Obtained clinical isolates characterised showed S. Typhimurium 1,4,[5],12:i:- with sole resistance to nalidixic acid, which had never been observed in Italy in monophasic S. Typhimurium, neither in humans nor in animals or foods. Epidemiological, microbiological and environmental investigations were conducted to try to identify the outbreak source. Cases were interviewed using a standardised questionnaire and microbiological tests were performed on human as well as environmental samples, including samples from fruit and vegetables, pigs, and surface water. Investigation results did not identify the final vehicle of human infection, although a link between the human cases and the contamination of irrigation water channels was suggested.

Spotting Culex pipiens from satellite: modeling habitat suitability in central Italy using Sentinel-2 and deep learning techniques.

Culex pipiens, an important vector of many vector borne diseases, is a species capable to feeding on a wide variety of hosts and adapting to different environments. To predict the potential distribution of Cx. pipiens in central Italy, this study integrated presence/absence data from a four-year entomological survey (2019-2022) carried out in the Abruzzo and Molise regions, with a datacube of spectral bands acquired by Sentinel-2 satellites, as patches of 224 × 224 pixels of 20 meters spatial resolution around each site and for each satellite revisit time. We investigated three scenarios: the baseline model, which considers the environmental conditions at the time of collection; the multitemporal model, focusing on conditions in the 2 months preceding the collection; and the MultiAdjacency Graph Attention Network (MAGAT) model, which accounts for similarities in temperature and nearby sites using a graph architecture. For the baseline scenario, a deep convolutional neural network (DCNN) analyzed a single multi-band Sentinel-2 image. The DCNN in the multitemporal model extracted temporal patterns from a sequence of 10 multispectral images; the MAGAT model incorporated spatial and climatic relationships among sites through a graph neural network aggregation method. For all models, we also evaluated temporal lags between the multi-band Earth Observation datacube date of acquisition and the mosquito collection, from 0 to 50 days. The study encompassed a total of 2,555 entomological collections, and 108,064 images (patches) at 20 meters spatial resolution. The baseline model achieved an F1 score higher than 75.8% for any temporal lag, which increased up to 81.4% with the multitemporal model. The MAGAT model recorded the highest F1 score of 80.9%. The study confirms the widespread presence of Cx. pipiens throughout the majority of the surveyed area. Utilizing only Sentinel-2 spectral bands, the models effectively capture early in advance the temporal patterns of the mosquito population, offering valuable insights for directing surveillance activities during the vector season. The methodology developed in this study can be scaled up to the national territory and extended to other vectors, in order to support the Ministry of Health in the surveillance and control strategies for the vectors and the diseases they transmit.

Culex pipiens distribution in Tunisia: Identification of suitable areas through Random Forest and MaxEnt approaches.

BACKGROUND: Tunisia has experienced several West Nile virus (WNV) outbreaks since 1997. Yet, there is limited information on the spatial distribution of the main WNV mosquito vector Culex pipiens suitability at the national level. OBJECTIVES: In the present study, our aim was to predict and evaluate the potential and current distribution of Cx. pipiens in Tunisia. METHODS: To this end, two species distribution models were used, i.e. MaxEnt and Random Forest. Occurrence records for Cx. pipiens were obtained from adult and larvae sampled in Tunisia from 2014 to 2017. Climatic and human factors were used as predictors to model the Cx. pipiens geographical distribution. Mean decrease accuracy and mean decrease Gini indices were calculated to evaluate the importance of the impact of different environmental and human variables on the probability distribution of Cx. pipiens. RESULTS: Suitable habitats were mainly distributed next to oases, in the north and eastern part of the country. The most important predictor was the population density in both models. The study found out that the governorates of Monastir, Nabeul, Manouba, Ariana, Bizerte, Gabes, Medenine and Kairouan are at highest epidemic risk. CONCLUSIONS: The potential distribution of Cx. pipiens coincides geographically with the observed distribution of the disease in humans in Tunisia. Our study has the potential for driving control effort in the fight against West Nile vector in Tunisia.

Epidemiological and Evolutionary Analysis of West Nile Virus Lineage 2 in Italy.

West Nile virus (WNV) is a mosquito-borne virus potentially causing serious illness in humans and other animals. Since 2004, several studies have highlighted the progressive spread of WNV Lineage 2 (L2) in Europe, with Italy being one of the countries with the highest number of cases of West Nile disease reported. In this paper, we give an overview of the epidemiological and genetic features characterising the spread and evolution of WNV L2 in Italy, leveraging data obtained from national surveillance activities between 2011 and 2021, including 46 newly assembled genomes that were analysed under both phylogeographic and phylodynamic frameworks. In addition, to better understand the seasonal patterns of the virus, we used a machine learning model predicting areas at high-risk of WNV spread. Our results show a progressive increase in WNV L2 in Italy, clarifying the dynamics of interregional circulation, with no significant introductions from other countries in recent years. Moreover, the predicting model identified the presence of suitable conditions for the 2022 earlier and wider spread of WNV in Italy, underlining the importance of using quantitative models for early warning detection of WNV outbreaks. Taken together, these findings can be used as a reference to develop new strategies to mitigate the impact of the pathogen on human and other animal health in endemic areas and new regions.

Species of mosquitoes present in Abruzzo and Molise and their possible role as vector of Usutu and West Nile viruses.

In 2019, entomological survey on mosquitoes was carried out in Abruzzo and Molise regions in central Italy to obtain data on local mosquito fauna. Collection sites were selected based on a previous ecoregion classification of the territory.  From 2019 to 2021 virological surveillance for West Nile virus (WNV) and Usutu virus (USUV) on mosquitoes was carried out in the same regions, selecting ecoregions where virus circulation and vector presence were more likely,  all mosquitoes were collected and identified, and the female mosquitoes were sorted in 3046 pools and tested for the presence of WNV and USUV by Real-time PCR. All pools tested negative for WND, while USUV was detected in 7 pools of Aedes caspius collected in Molise region, 17 pools of Culex pipiens s.l. (2 collected in Molise, 15 in Abruzzo), and 1 pool of Culiseta longiareolata collected in Molise. These results suggests the presence of an USUV enzootic cycle, maintained by Culex pipiens s.l. and Aedes caspius in both Italian regions, as well as providing a useful picture in terms of species presence and abundance for both regions. Ecoregions proved to be a very valuable tool in determining high risk areas for vector borne diseases.

Canine Leishmaniasis: Serological Results in Private and Kennel Dogs Tested over a Six-Year Period (2009-2014) in Abruzzo and Molise Regions, Italy.

This paper reports the results of serological tests for the detection of antibodies against Leishmania spp. in Abruzzo and Molise regions from 2009 to 2014, with the aim of evaluating the presence and distribution of canine leishmaniasis. Data were extracted from the Laboratory Information Management System (LIMS) of the Istituto Zooprofilattico Sperimentale of Abruzzo and Molise, and then the dog identification numbers were matched with those stored in the Canine Registries of the two regions to get information about the age of dogs at time of testing. Dogs were considered positive when having an IFAT (Indirect Fluorescent Antibody Test) titer ≥1:80. In total, 41,631 dogs were tested, 85.3% from Abruzzo and 14.7% from Molise. At the provincial level, the percentage of positive dogs ranged from 5.2% (L'Aquila, Abruzzo region) to 21.8% (Campobasso, Molise region). Findings are consistent with the hypothesis that in the coastal areas, the relationships between the host, the vector, and the agent are more favorable for the spreading of CanL, and it seems that densely populated urban internal areas have less favorable conditions. Being a dog hosted in a kennel seems not to be a factor increasing the probability that dogs show positivity, even in long-term sheltering conditions.

Defining ecological regions in Italy based on a multivariate clustering approach: A first step towards a targeted vector borne disease surveillance.

Ecoregionalization is the process by which a territory is classified in similar areas according to specific environmental and climatic factors. The climate and the environment strongly influence the presence and distribution of vectors responsible for significant human and animal diseases worldwide. In this paper, we developed a map of the eco-climatic regions of Italy adopting a data-driven spatial clustering approach using recent and detailed spatial data on climatic and environmental factors. We selected seven variables, relevant for a broad set of human and animal vector-borne diseases (VBDs): standard deviation of altitude, mean daytime land surface temperature, mean amplitude and peak timing of the annual cycle of land surface temperature, mean and amplitude of the annual cycle of greenness value, and daily mean amount of rainfall. Principal Component Analysis followed by multivariate geographic clustering using the k-medoids technique were used to group the pixels with similar characteristics into different ecoregions, and at different spatial resolutions (250 m, 1 km and 2 km). We showed that the spatial structure of ecoregions is generally maintained at different spatial resolutions and we compared the resulting ecoregion maps with two datasets related to Bluetongue vectors and West Nile Disease (WND) outbreaks in Italy. The known characteristics of Culicoides imicola habitat were well captured by 2/22 specific ecoregions (at 250 m resolution). Culicoides obsoletus/scoticus occupy all sampled ecoregions, according to its known widespread distribution across the peninsula. WND outbreak locations strongly cluster in 4/22 ecoregions, dominated by human influenced landscape, with intense cultivations and complex irrigation network. This approach could be a supportive tool in case of VBDs, defining pixel-based areas that are conducive environment for VBD spread, indicating where surveillance and prevention measures could be prioritized in Italy. Also, ecoregions suitable to specific VBDs vectors could inform entomological surveillance strategies.

Estimating the prevalence of Brucellosis in cattle in Zimbabwe from samples submitted to the Central Veterinary Laboratory between 2010 and 2014.

Brucellosis is a disease caused by bacteria belonging to the genus Brucella, which is endemic in sub-Saharan African countries, including Zimbabwe. Zimbabwe has a widespread dairy industry with peri-urban dairy establishments built in order to improve milk availability to rural communities. This study has been the first attempt to estimate the prevalence of brucellosis in Zimbabwe as a whole, using samples submitted to the Central veterinary laboratory between 2010 and 2014. A total of 156 farms were tested with Rose Bengal Test (RBT), Complement Fixation Test (CFT) and Milk Ring Test (MRT). Parallel testing was used to determine whether or not a farm was to be considered positive: 30.1% (95% C.I.: 23.5% - 37.8%) of the farms tested were found positive (47/156). Harare district had the highest number of sample submissions with 6 out of 17 farms testing positive (P = 37.5%; 95% C.I.: 18.4% - 61.7%). Awareness of milk-borne zoonoses is reportedly generally low in farmers (41.5%). This is even more the case in small-holder farmers who have higher likelihoods of selling or ingesting raw milk compared with dairy farmers. The results show the need to carry out surveillance of brucellosis in cattle in Zimbabwe to understand the spatial distribution of the disease in the country. This is particularly relevant given the zoonotic and economic implications of this disease.

SeaGIS Abruzzo: A publicly available atlas of marine uses and natural resources in the Adriatic Sea Region.

In the Adriatic Sea, the European Union supported a cross-border cooperation research program, during which digital spatial data on shellfish production and relaying areas, regulated conditions on fishing activities, protected areas and restocking structures, administrative boundaries and sea bottom characteristics, were collated from digital repositories in various institutions and paper documents. A web-based geographical information system was developed to share data of the sea facing the Abruzzi region and to explore the spatial distribution of marine resources and maritime activities, thus focussing and facilitating fisheries management and providing a potential support to the regional planning of resource exploitation.

Emerging Mosquito-Borne Threats and the Response from European and Eastern Mediterranean Countries.

Mosquito-borne viruses are the cause of some of the greatest burdens to human health worldwide, particularly in tropical regions where both human populations and mosquito numbers are abundant. Due to a combination of anthropogenic change, including the effects on global climate and wildlife migration there is strong evidence that temperate regions are undergoing repeated introduction of mosquito-borne viruses and the re-emergence of viruses that previously were not detected by surveillance. In Europe, the repeated introductions of West Nile and Usutu viruses have been associated with bird migration from Africa, whereas the autochthonous transmission of chikungunya and dengue viruses has been driven by a combination of invasive mosquitoes and rapid transcontinental travel by infected humans. In addition to an increasing number of humans at risk, livestock and wildlife, are also at risk of infection and disease. This in turn can affect international trade and species diversity, respectively. Addressing these challenges requires a range of responses both at national and international level. Increasing the understanding of mosquito-borne transmission of viruses and the development of rapid detection methods and appropriate therapeutics (vaccines / antivirals) all form part of this response. The aim of this review is to consider the range of mosquito-borne viruses that threaten public health in Europe and the eastern Mediterranean, and the national response of a number of countries facing different levels of threat.

Seroprevalence of West Nile virus in horses in different Moroccan regions.

West Nile virus-associated disease is one of the most widespread vector-borne diseases in the world. In Morocco, the first cases were reported in horses in 1996 and the disease re-emerged in 2003 and in 2010. The objective of this work was to study the epidemiological situation of WNV-associated infection in Morocco, by quantifying the seroprevalence of anti-WNV IgM and IgG antibodies in horses in different bioclimatic regions-zones of Morocco in 2011. During the months of May, June and July 2011, 840 serum samples were collected from horses in four regions characterized by different environmental and climatic features such as altitude, temperature and precipitation. These environmental-climatic regions are: the Atlantic plateaus of the Gharb and pre-Rif region, the North Atlasic plains and plateaus region, the Atlas Mountains and pre-Atlas region and the plains and plateaus of the Oriental region. All samples were tested for the anti-WNV IgG antibodies by ELISA and positive sera were confirmed by virus neutralization (VN). An anti-WNV antibody prevalence map was developed. A total of 261 samples (31%) were found positive by both techniques. The prevalence of the infection was higher in the Atlantic plateaus of the Gharb and pre-Rif region, in the northern part of the country. Available data concerning the previous WNV-associated disease outbreaks in Morocco and the preliminary results of this serological survey suggest that the Moroccan northwest is the region at highest risk for WNV circulation. In this region, the climate is more humid with higher rainfall than other regions and milder winter temperatures exist. In the same area, the presence of migratory bird settlements may affect the risk of virus introduction and amplification.

Eco-climatic indicators for three Culicoides species of the Obsoletus complex in Italy.

Bluetongue, Schmallenberg and African horse sickness viruses are transmitted by vectors belonging to the genus Culicoides (Diptera: Ceratopogonidae). Among this genus, species of the Obsoletus complex play a crucial role in Europe. In Italy the complex includes three species: Culicoides obsoletus sensu strictu, Culicoides scoticus and Culicoides montanus. These three sibling species were identified in 80 collection sites across Italy through a multiplex PCR test. Sixty­four sites were classified with a predominant species through a Bayesian approach. Environmental, topographic and climatic factors together with landscape metrics were investigated in each species group using the non­parametric Mann­Whitney test. Culicoides obsoletus s.s. resulted the most widely distributed species across the peninsula (51 sites). This species was collected in many eco­climatic conditions, at a wide range of temperature and altitudes, mainly in anthropogenic landscape. Conversely C. scoticus collection sites were dominated by natural vegetated areas or forest, at medium higher altitudes, preferably in a wilder and more pristine environment (predominant species in 8 sites). Culicoides montanus was a rarer species, statistically predominant in only 3 sites located in Southern Italy, characterized by temperatures higher than the other species. These results, together with other on­going researches on the vector competence of the species belonging to the Obsoletus complex, and with investigation of larval and breeding habitats, could greatly improve epidemiological knowledge of possible spreading Culicoides­borne viruses.

The 'Culicoides obsoletus group' in Italy: relative abundance, geographic range, and role as vector for Bluetongue virus.

As Bluetongue virus (BTV) spread in Italy following its first incursion in 2000, it soon became apparent that, besides Culicoides imicola, additional species of the subgenus Avaritia were involved as vectors, namely one or more of the species that belong to the so-called 'Culicoides obsoletus group', which comprises C. dewulfi, C. chiopterus, C. obsoletus sensu stricto, C. scoticus and C. montanus; the three last named species are considered generally as forming the Obsoletus complex. This study presents the findings made over the last decade and more, within the Italian entomological surveillance program for Bluetongue. It describes the integrated morphological and molecular approach used to identify the species of the 'C. obsoletus group', maps in detail their relative abundances and geographic ranges in Italy, clarifies the hitherto unknown comparative seasonal abundances of C. obsoletus s.s. and C. scoticus in a site in Central Italy, and provides further details on the potential vector status of five species of the 'C. obsoletus group', with emphasis on C. obsoletus s.s., C. scoticus and C. montanus. Unlike the situation in Northern Europe, Culicoides dewulfi and C. chiopterus are uncommon to rare in Italy. In contrast, the Obsoletus complex occurs abundantly throughout Italy, with C. obsoletus s.s. being the most prevalent and ecologically adaptive of the three species making up the complex. A longitudinal study conducted at a site in Central Italy revealed that: (i) species of the Obsoletus complex prefer horses to sheep; (ii) their parity rates range from 10% (March) to 56% (November); (iii) throughout the year C. scoticus is consistently more abundant than C. obsoletus s.s.; (iv) abundances in both, C. obsoletus s.s. and C. scoticus, peak in May-June, with the peak of the latter species being more evident. Bluetongue virus was first isolated from wild caught midges of the Obsoletus complex in 2002. Thereafter, pools of selected parous midges collected across Italy, and during multiple outbreaks of BT, have been found consistently PCR-positive for the virus. More recently, viral RNA has been detected in field specimens of C. dewulfi, C. obsoletus s.s., C. scoticus and C. montanus.

Epizootic haemorrhagic disease in Italy: vector competence of indigenous Culicoides species and spatial multicriteria evaluation of vulnerability.

Epizootic haemorrhagic disease (EHD) is an infectious non-contagious viral disease transmitted by Culicoides, which affects wild and domestic ruminants. The disease has never been reported in Europe, however recently outbreaks of EHD occurred in the Mediterranean Basin. Consequently, the risk that Epizootic haemorrhagic disease virus (EHDV) might spread in Italy cannot be ignored. The aim of this study was to evaluate the risk of EHDV transmission in Italy, in case of introduction, through indigenous potential vectors. In Italy, the most spread and abundant Culicoides species associated to livestock are Culicoides imicola and the members of the Obsoletus complex. Culicoides imicola is a competent vector of EHDV, whereas the vector status of the Obsoletus complex has not been assessed yet. Thus, its oral susceptibility to EHDV was here preliminary evaluated. To evaluate the risk of EHDV transmission a geographical information system-based Multi-Criteria Evaluation approach was adopted. Distribution of vector species and host density were used as predictors of potential suitable areas for EHDV transmission, in case of introduction in Italy. This study demonstrates that the whole peninsula is suitable for the disease, given the distribution and abundance of hosts and the competence of possible indigenous vectors.

OIEBTLABNET: the web-based network of the OIE Bluetongue Reference Laboratories.

Bluetongue (BT) is a mild to severe disease of domestic and wild ruminants caused by the Bluetongue virus (BTV) and generally transmitted by Culicoides biting midges. Its occurrence also determines a livestock trade ban in affected countries with severe economic consequences on national and international trade. For this reason, in May 2011, the OIE encouraged the OIE Reference Laboratories to establish and maintain a BT network to provide expertise and training to the OIE and OIE Member Countries for BT diagnosis, surveillance and control. The network is constantly sustained by world leading scientists in the field of virology, epidemiology, serology, entomology and vaccine development. The website, available at http://oiebtnet.izs.it/btlabnet/, hosts an Information System containing data on BTV outbreaks and strains and a WebGIS that distributes maps on BTV occurrence. In this paper we describe the applications and present the benefits derived from the use of the WebGIS in the context of BT international surveillance network.

Genetic characterization of Brucella melitensis and Brucella abortus geographical clusters in Italy.

The genetic diversity of Brucella melitensis and Brucella abortus strains isolated in 199 cattle and sheep from 156 brucellosis outbreaks which occurred in 8 regions of Southern Italy in 2011, was determined using a Multiple-Locus Variable Number of Tandem Repeats Analysis approach. The existence of possible genetic clusters was verified through a hierarchical cluster analysis based on 'single link', which is closely related to the minimum spanning tree. The Hamming weighted distance matrix was adopted in the analysis. All calculations were performed using R and the additional libraries phangorn and Cluster. For a number of clusters, ranging from 2 to 15, the average silhouette width was calculated. The number of clusters adopted was identified according to the maximum average silhouette width. For B. abortus and B. melitensis, 6 and 11 genetic clusters were identified, respectively. Three out of 6 B. abortus clusters included the 96.7% of all B. abortus isolates. Clusters were clearly geographically separated, and this highlighted the known epidemiological links among them. Brucella melitensis genotypes resulted more heterogeneous; the 3 more representative genetic clusters included 79.7% of all B. melitensis isolates. A clear geographical clusterization of genotypes is recognizable only for 1 cluster, whereas the others are more widespread across Southern Italy. The genetic characterization of Brucella strains isolated from animals may be a useful tool to better understand the epidemiology and dissemination patterns of this pathogen through host populations.

Smartphone and GPS technology for free-roaming dog population surveillance - a methodological study.

Free-roaming dogs (FRD) represent a potential threat to the quality of life in cities from an ecological, social and public health point of view. One of the most urgent concerns is the role of uncontrolled dogs as reservoirs of infectious diseases transmittable to humans and, above all, rabies. An estimate of the FRD population size and characteristics in a given area is the first step for any relevant intervention programme. Direct count methods are still prominent because of their non-invasive approach, information technologies can support such methods facilitating data collection and allowing for a more efficient data handling. This paper presents a new framework for data collection using a topological algorithm implemented as ArcScript in ESRI® ArcGIS software, which allows for a random selection of the sampling areas. It also supplies a mobile phone application for Android® operating system devices which integrates Global Positioning System (GPS) and Google MapsTM. The potential of such a framework was tested in 2 Italian regions. Coupling technological and innovative solutions associated with common counting methods facilitate data collection and transcription. It also paves the way to future applications, which could support dog population management systems.