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Mansfield KL, Schilling M, Sanders C, Holding M, Johnson N. Arthropod-Borne Viruses of Human and Animal Importance: Overwintering in Temperate Regions of Europe during an Era of Climate Change. Microorganisms 2024; 12:1307. [PMID: 39065076 PMCID: PMC11278640 DOI: 10.3390/microorganisms12071307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/20/2024] [Accepted: 06/22/2024] [Indexed: 07/28/2024] Open
Abstract
The past three decades have seen an increasing number of emerging arthropod-borne viruses in temperate regions This process is ongoing, driven by human activities such as inter-continental travel, combined with the parallel emergence of invasive arthropods and an underlying change in climate that can increase the risk of virus transmission and persistence. In addition, natural events such as bird migration can introduce viruses to new regions. Despite the apparent regularity of virus emergence, arthropod-borne viruses circulating in temperate regions face the challenge of the late autumn and winter months where the arthropod vector is inactive. Viruses therefore need mechanisms to overwinter or they will fail to establish in temperate zones. Prolonged survival of arthropod-borne viruses within the environment, outside of both vertebrate host and arthropod vector, is not thought to occur and therefore is unlikely to contribute to overwintering in temperate zones. One potential mechanism is continued infection of a vertebrate host. However, infection is generally acute, with the host either dying or producing an effective immune response that rapidly clears the virus. There are few exceptions to this, although prolonged infection associated with orbiviruses such as bluetongue virus occurs in certain mammals, and viraemic vertebrate hosts therefore can, in certain circumstances, provide a route for long-term viral persistence in the absence of active vectors. Alternatively, a virus can persist in the arthropod vector as a mechanism for overwintering. However, this is entirely dependent on the ecology of the vector itself and can be influenced by changes in the climate during the winter months. This review considers the mechanisms for virus overwintering in several key arthropod vectors in temperate areas. We also consider how this will be influenced in a warming climate.
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Affiliation(s)
- Karen L. Mansfield
- Vector Borne Diseases, Virology Department, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey KT15 3NB, UK; (K.L.M.); (M.S.)
| | - Mirjam Schilling
- Vector Borne Diseases, Virology Department, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey KT15 3NB, UK; (K.L.M.); (M.S.)
| | | | - Maya Holding
- Virology and Pathogenesis Group, UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK;
| | - Nicholas Johnson
- Vector Borne Diseases, Virology Department, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey KT15 3NB, UK; (K.L.M.); (M.S.)
- Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK
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Dähn O, Werner D, Mathieu B, Kampen H. Large-Scale Cytochrome C Oxidase Subunit I Gene Data Analysis for the Development of a Multiplex Polymerase Chain Reaction Test Capable of Identifying Biting Midge Vector Species and Haplotypes (Diptera: Ceratopogonidae) of the Culicoides Subgenus Avaritia Fox, 1955. Genes (Basel) 2024; 15:323. [PMID: 38540382 PMCID: PMC10969821 DOI: 10.3390/genes15030323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 02/22/2024] [Accepted: 02/28/2024] [Indexed: 06/14/2024] Open
Abstract
The emergence of culicoid-transmitted bluetongue and Schmallenberg viruses in several European countries demonstrated the ability of indigenous biting midge species to transmit pathogens. Entomologic research programs identified members of the Obsoletus Group (Culicoides subgenus Avaritia) as keyplayers in disease epidemiology in Europe. However, morphological identification of potential vectors is challenging due to the recent discovery of new genetic variants (haplotypes) of C. obsoletus sensu stricto (s.s.), forming distinct clades. In this study, 4422 GenBank entries of the mitochondrial cytochrome c oxidase subunit I (COI) gene of subgenus Avaritia members of the genus Culicoides were analyzed to develop a conventional multiplex PCR, capable of detecting all vector species and clades of the Western Palearctic in this subgenus. Numerous GenBank entries incorrectly assigned to a species were identified, analyzed and reassigned. The results suggest that the three C. obsoletus clades represent independent species, whereas C. montanus should rather be regarded as a genetic variant of C. obsoletus s.s. Based on these findings, specific primers were designed and validated with DNA material from field-caught biting midges which achieved very high diagnostic sensitivity (100%) when compared to an established reference PCR (82.6%).
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Affiliation(s)
- Oliver Dähn
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald, Germany
| | - Doreen Werner
- Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Str. 84, 15374 Müncheberg, Germany
| | - Bruno Mathieu
- Institutes of Bacteriology and Parasitology, Medical Faculty, University of Strasbourg, UR 3073 PHAVI, 67000 Strasbourg, France
| | - Helge Kampen
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald, Germany
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Field-Reassortment of Bluetongue Virus Illustrates Plasticity of Virus Associated Phenotypic Traits in the Arthropod Vector and Mammalian Host In Vivo. J Virol 2022; 96:e0053122. [PMID: 35727032 PMCID: PMC9278112 DOI: 10.1128/jvi.00531-22] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Segmented RNA viruses are a taxonomically diverse group that can infect plant, wildlife, livestock and human hosts. A shared feature of these viruses is the ability to exchange genome segments during coinfection of a host by a process termed "reassortment." Reassortment enables rapid evolutionary change, but where transmission involves a biological arthropod vector, this change is constrained by the selection pressures imposed by the requirement for replication in two evolutionarily distant hosts. In this study, we use an in vivo, host-arbovirus-vector model to investigate the impact of reassortment on two phenotypic traits, virus infection rate in the vector and virulence in the host. Bluetongue virus (BTV) (Reoviridae) is the causative agent of bluetongue (BT), an economically important disease of domestic and wild ruminants and deer. The genome of BTV comprises 10 linear segments of dsRNA, and the virus is transmitted between ruminants by Culicoides biting midges (Diptera: Ceratopogonidae). Five strains of BTV representing three serotypes (BTV-1, BTV-4, and BTV-8) were isolated from naturally infected ruminants in Europe and ancestral/reassortant lineage status assigned through full genome sequencing. Each strain was then assessed in parallel for the ability to replicate in vector Culicoides and to cause BT in sheep. Our results demonstrate that two reassortment strains, which themselves became established in the field, had obtained high replication ability in C. sonorensis from one of the ancestral virus strains, which allowed inferences of the genome segments conferring this phenotypic trait. IMPORTANCE Reassortment between virus strains can lead to major shifts in the transmission parameters and virulence of segmented RNA viruses, with consequences for spread, persistence, and impact. The ability of these pathogens to adapt rapidly to their environment through this mechanism presents a major challenge in defining the conditions under which emergence can occur. Utilizing a representative mammalian host-insect vector infection and transmission model, we provide direct evidence of this phenomenon in closely related ancestral and reassortant strains of BTV. Our results demonstrate that efficient infection of Culicoides observed for one of three ancestral BTV strains was also evident in two reassortant strains that had subsequently emerged in the same ecosystem.
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A Qualitative Risk Assessment for Bluetongue Disease and African Horse Sickness: The Risk of Entry and Exposure at a UK Zoo. Viruses 2022; 14:v14030502. [PMID: 35336912 PMCID: PMC8950286 DOI: 10.3390/v14030502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/25/2022] [Accepted: 02/25/2022] [Indexed: 12/10/2022] Open
Abstract
Bluetongue virus (BTV) and African horse sickness virus (AHSV) cause economically important diseases that are currently exotic to the United Kingdom (UK), but have significant potential for introduction and onward transmission. Given the susceptibility of animals kept in zoo collections to vector-borne diseases, a qualitative risk assessment for the introduction of BTV and AHSV to ZSL London Zoo was performed. Risk pathways for each virus were identified and assessed using published literature, animal import data and outputs from epidemiological models. Direct imports of infected animals, as well as wind-borne infected Culicoides, were considered as routes of incursion. The proximity of ongoing disease events in mainland Europe and proven capability of transmission to the UK places ZSL London Zoo at higher risk of BTV release and exposure (estimated as low to medium) than AHSV (estimated as very low to low). The recent long-range expansion of AHSV into Thailand from southern Africa highlights the need for vector competence studies of Palearctic Culicoides for AHSV to assess the risk of transmission in this region.
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The Absence of Abdominal Pigmentation in Livestock Associated Culicoides following Artificial Blood Feeding and the Epidemiological Implication for Arbovirus Surveillance. Pathogens 2021; 10:pathogens10121571. [PMID: 34959526 PMCID: PMC8705276 DOI: 10.3390/pathogens10121571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 12/02/2022] Open
Abstract
Culicoides midges (Diptera: Ceratopogonidae), the vectors of economically important arboviruses such as bluetongue virus and African horse sickness virus, are of global importance. In the absence of transovarial transmission, the parity rate of a Culicoides population provides imperative information regarding the risk of virus dispersal. Abdominal pigmentation, which develops after blood feeding and ovipositioning, is used as an indicator of parity in Culicoides. During oral susceptibility trials over the last three decades, a persistent proportion of blood engorged females did not develop pigment after incubation. The present study, combining a number of feeding trials and different artificial feeding methods, reports on this phenomenon, as observed in various South African and Italian Culicoides species and populations. The absence of pigmentation in artificial blood-fed females was found in at least 23 Culicoides species, including important vectors such as C. imicola, C. bolitinos, C. obsoletus, and C. scoticus. Viruses were repeatedly detected in these unpigmented females after incubation. Blood meal size seems to play a role and this phenomenon could be present in the field and requires consideration, especially regarding the detection of virus in apparent “nulliparous” females and the identification of overwintering mechanisms and seasonally free vector zones.
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Korkmaz C, Alten B, Erol U, Deniz A. Updated checklist of Culicoides Latreille (Diptera: Ceratopogonidae) of Turkey with ten new records. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2021; 46:124-136. [PMID: 35230016 DOI: 10.52707/1081-1710-46.2.124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/24/2021] [Indexed: 06/14/2023]
Abstract
We investigated the Culicoides fauna in Turkey during the years 2016-2019 in the process of entomological surveillance for arboviral diseases. The entomological survey was conducted at 104 sampling stations in 51 provinces in Turkey during four consecutive years. There were approximately 450,000 specimens and 59 identified species collected during the surveillance. Ten species were newly recorded for Turkey: C. chiopterus, C. grisescens, C. paradoxalis, C. santonicus, C. poperinghensis, C. sergenti, C. tbilisicus, C. comosioculatus, C. haranti, and C. univittatus. Identification of C. chiopterus and C. grisescens was confirmed using species-specific PCR and DNA sequencing. With our recent findings, previous data were critically reviewed and updated, and the number of Culicoides species has been increased to 71 for Turkey. The presence of C. chiopterus has particular importance due to its potential vector status for bluetongue virus (BTV) and Schmallenberg virus (SBV). This study presents result of the first large-scale integrated faunistic survey on Culicoides species in Turkey.
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Affiliation(s)
- Cagla Korkmaz
- Veterinary Control Central Research Institute, Ankara, Turkey,
- Hacettepe University, Graduate School of Science and Engineering, Ankara, Turkey
| | - Bulent Alten
- Hacettepe University, Faculty of Science, Department of Biology, Ecology Division, VERG laboratories, Beytepe, Ankara, Turkey
| | - Ufuk Erol
- Sivas Cumhuriyet University, Faculty of Veterinary Medicine, Department of Parasitology, Sivas, Turkey
| | - Ahmet Deniz
- Veterinary Control Central Research Institute, Ankara, Turkey
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Aguilar-Vega C, Rivera B, Lucientes J, Gutiérrez-Boada I, Sánchez-Vizcaíno JM. A study of the composition of the Obsoletus complex and genetic diversity of Culicoides obsoletus populations in Spain. Parasit Vectors 2021; 14:351. [PMID: 34217330 PMCID: PMC8254917 DOI: 10.1186/s13071-021-04841-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 06/11/2021] [Indexed: 11/10/2022] Open
Abstract
Background The Culicoides obsoletus species complex (henceforth ‘Obsoletus complex’) is implicated in the transmission of several arboviruses that can cause severe disease in livestock, such as bluetongue, African horse sickness, epizootic hemorrhagic disease and Schmallenberg disease. Thus, this study aimed to increase our knowledge of the composition and genetic diversity of the Obsoletus complex by partial sequencing of the cytochrome c oxidase I (cox1) gene in poorly studied areas of Spain. Methods A study of C. obsoletus populations was carried out using a single-tube multiplex polymerase chain reaction (PCR) assay that was designed to differentiate the Obsoletus complex sibling species Culicoides obsoletus and Culicoides scoticus, based on the partial amplification of the cox1 gene, as well as cox1 georeferenced sequences from Spain available at GenBank. We sampled 117 insects of the Obsoletus complex from six locations and used a total of 238 sequences of C. obsoletus (ss) individuals (sampled here, and from GenBank) from 14 sites in mainland Spain, the Balearic Islands and the Canary Islands for genetic diversity and phylogenetic analyses. Results We identified 90 C. obsoletus (ss), 19 Culicoides scoticus and five Culicoides montanus midges from the six collection sites sampled, and found that the genetic diversity of C. obsoletus (ss) were higher in mainland Spain than in the Canary Islands. The multiplex PCR had limitations in terms of specificity, and no cryptic species within the Obsoletus complex were identified. Conclusions Within the Obsoletus complex, C. obsoletus (ss) was the predominant species in the analyzed sites of mainland Spain. Information about the species composition of the Obsoletus complex could be of relevance for future epidemiological studies when specific aspects of the vector competence and capacity of each species have been identified. Our results indicate that the intraspecific divergence is higher in C. obsoletus (ss) northern populations, and demonstrate the isolation of C. obsoletus (ss) populations of the Canary Islands. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04841-z.
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Affiliation(s)
- Cecilia Aguilar-Vega
- Animal Health Department, Faculty of Veterinary Medicine, VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain.
| | - Belén Rivera
- Animal Health Department, Faculty of Veterinary Medicine, VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain
| | - Javier Lucientes
- Department of Animal Pathology (Animal Health), Faculty of Veterinary Medicine, AgriFood Institute of Aragón IA2, University of Zaragoza, Zaragoza, Spain
| | - Isabel Gutiérrez-Boada
- Animal Health Department, Faculty of Veterinary Medicine, VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain
| | - José Manuel Sánchez-Vizcaíno
- Animal Health Department, Faculty of Veterinary Medicine, VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain
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Van den Eynde C, Sohier C, Matthijs S, De Regge N. Temperature and food sources influence subadult development and blood-feeding response of Culicoides obsoletus (sensu lato) under laboratory conditions. Parasit Vectors 2021; 14:300. [PMID: 34090481 PMCID: PMC8180032 DOI: 10.1186/s13071-021-04781-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 05/11/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Culicoides obsoletus (s.l.) is the most abundant Culicoides species in northern Europe and an important vector of bluetongue virus and Schmallenberg virus. Nevertheless, information on its subadult life stages remains scarce and no laboratory-reared colony exists. METHODS C. obsoletus (s.l.) adults were collected in Belgium and transferred to the laboratory in an attempt to establish a laboratory-reared colony. C. obsoletus (s.l.) were reared from eggs to adults at different temperatures (28 °C, 24 °C, 20/16 °C) and under different food regimes. RESULTS The most suitable temperature for rearing seemed to be 24 °C for most developmental parameters, but resulted in a biased 3:1 male/female sex ratio. The latter could be optimized to a 1:1 sex ratio when a 20/16 °C day/night temperature gradient was applied, but rearing at these low temperature conditions resulted in significantly lower egg hatching and pupation rates and a longer subadult development time. Independent of the rearing temperature, adding dung as an additional food source during larval development resulted in a significantly higher adult emergence rate and a decrease in subadult development time. Furthermore, blood-feeding rates of field-collected C. obsoletus (s.l.) were compared for different blood sources and feeding systems. The overall blood-feeding success was low and only successful with cotton pledgets (2.7% blood-fed midges) and through a membrane system with chicken skin (3.5% blood-fed midges). Higher feeding rates were obtained on cattle blood compared to sheep blood. CONCLUSIONS These results will help us to determine the necessary conditions to rear a viable laboratory colony of this important vector species, although further optimization is still required.
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Affiliation(s)
- Claudia Van den Eynde
- Sciensano, Enzootic, Vector-Borne and Bee Diseases, Groeselenberg 99, 1180, Brussels, Belgium.
| | - Charlotte Sohier
- Sciensano, Enzootic, Vector-Borne and Bee Diseases, Groeselenberg 99, 1180, Brussels, Belgium
| | - Severine Matthijs
- Sciensano, Enzootic, Vector-Borne and Bee Diseases, Groeselenberg 99, 1180, Brussels, Belgium
| | - Nick De Regge
- Sciensano, Enzootic, Vector-Borne and Bee Diseases, Groeselenberg 99, 1180, Brussels, Belgium
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de Beer CJ, Boikanyo SNB, Venter GJ. Assessment of the Hemotek® system for the in vitro feeding of field-collected Culicoides imicola (Diptera: Ceratopogonidae) in South Africa. MEDICAL AND VETERINARY ENTOMOLOGY 2021; 35:177-186. [PMID: 32990991 DOI: 10.1111/mve.12484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/27/2020] [Accepted: 09/04/2020] [Indexed: 06/11/2023]
Abstract
The optimising and standardisation of in vitro blood feeding protocols for field-collected Culicoides species (Diptera: Ceratopogonidae) will be of essence for the comparison of the vector competencies of various populations of viruses of veterinary importance and the establishment of laboratory colonies of putative vector species. A custom-made feeding chamber to accommodate the small size of Culicoides imicola Kieffer was designed for the commercially available Hemotek® system and compared to existing membrane and cotton pledge feeding methods. High feeding rates coupled to higher mean blood meal volume than that of the existing OVI device indicated that the Hemotek system will be suitable for the feeding of field-collected Culicoides. The Hemotek system was subsequently used to identify factors that may affect feeding success in the laboratory. Evaluated factors were the source (host) and temperature of the blood meal, time of the day of feeding, the position of the blood reservoir in relation to the midges and exposure time to the blood. While only feeding orientation and the temperature of the blood source seems to significantly affect the feeding rate, all the factors did influence the volume of blood consumed.
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Affiliation(s)
- C J de Beer
- Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Insect Pest Control Laboratory, Vienna, Austria
- Epidemiology, Vectors and Parasites, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
| | - S N B Boikanyo
- Epidemiology, Vectors and Parasites, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
| | - G J Venter
- Epidemiology, Vectors and Parasites, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
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Barceló C, Purse BV, Estrada R, Lucientes J, Miranda MÁ, Searle KR. Environmental Drivers of Adult Seasonality and Abundance of Biting Midges Culicoides (Diptera: Ceratopogonidae), Bluetongue Vector Species in Spain. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:350-364. [PMID: 32885822 DOI: 10.1093/jme/tjaa160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Indexed: 06/11/2023]
Abstract
Bluetongue is a viral disease affecting wild and domestic ruminants transmitted by several species of biting midges Culicoides Latreille. The phenology of these insects were analyzed in relation to potential environmental drivers. Data from 329 sites in Spain were analyzed using Bayesian Generalized Linear Mixed Model (GLMM) approaches. The effects of environmental factors on adult female seasonality were contrasted. Obsoletus complex species (Diptera: Ceratopogonidae) were the most prevalent across sites, followed by Culicoides newsteadi Austen (Diptera: Ceratopogonidae). Activity of female Obsoletus complex species was longest in sites at low elevation, with warmer spring average temperatures and precipitation, as well as in sites with high abundance of cattle. The length of the Culicoides imicola Kieffer (Diptera: Ceratopogonidae) female adult season was also longest in sites at low elevation with higher coverage of broad-leaved vegetation. Long adult seasons of C. newsteadi were found in sites with warmer autumns and higher precipitation, high abundance of sheep. Culicoides pulicaris (Linnaeus) (Diptera: Ceratopogonidae) had longer adult periods in sites with a greater number of accumulated degree days over 10°C during winter. These results demonstrate the eco-climatic and seasonal differences among these four taxa in Spain, which may contribute to determining sites with suitable environmental circumstances for each particular species to inform assessments of the risk of Bluetongue virus outbreaks in this region.
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Affiliation(s)
- Carlos Barceló
- Applied Zoology and Animal Conservation Research Group, Department of Biology, University of the Balearic Islands (UIB), Ctra. Valldemossa Km 7.5, Palma de Mallorca, Spain
| | - Bethan V Purse
- Centre for Ecology and Hydrology, Oxfordshire, United Kingdom
| | - Rosa Estrada
- Department of Animal Pathology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
| | - Javier Lucientes
- Department of Animal Pathology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
| | - Miguel Á Miranda
- Applied Zoology and Animal Conservation Research Group, Department of Biology, University of the Balearic Islands (UIB), Ctra. Valldemossa Km 7.5, Palma de Mallorca, Spain
| | - Kate R Searle
- Centre for Ecology and Hydrology, Bush Estate, Edinburgh, Scotland
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Bray D, Isberg E, Hillbur Y, Ignell R. Influence of light and kairomone baiting systems on trap collections of biting midges in southern Sweden. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2020; 45:45-56. [PMID: 32492275 DOI: 10.1111/jvec.12372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/03/2020] [Indexed: 06/11/2023]
Abstract
Effective surveillance is essential for protecting livestock from Culicoides biting midges and the viruses they transmit. The objective of this study was to determine how the baiting system used in traps (UV, incandescent light, incandescent light with CO2 , and incandescent light with CO2 and 1-octen-3-ol) influences estimates of midge population abundance, parity, and diel activity. This was achieved through a standardized trapping protocol conducted in three habitats in Sweden. UV light traps caught the most Culicoides species and more C. obsoletus complex females than incandescent light traps. Traps baited with CO2 plus 1-octen-3-ol caught more female C. impunctatus than incandescent light traps. No consistent effect of bait type was found on C. obsoletus parity rate, as estimated from the proportion of midges with presence or absence of pigmentation. Midge activity, as reflected by trap catches, peaked between -3 h and +3 h relative to sunset, with UV traps catching significantly more female C. obsoletus complex and C. impunctatus at and after sunset than before sunset. We conclude that baiting system can influence biting midge collections, even using identical traps. Effective surveillance may require more than one bait type and kairomones to attract species that do not feed exclusively on cattle.
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Affiliation(s)
- Daniel Bray
- Swedish University of Agricultural Sciences, Department of Plant Protection Biology, Unit of Chemical Ecology, Box 102, 230 53, Alnarp, Sweden
- Agriculture, Health and Environment Department, Natural Resources Institute, University of Greenwich, Kent, ME4 4TB, UK
| | - Elin Isberg
- Swedish University of Agricultural Sciences, Department of Plant Protection Biology, Unit of Chemical Ecology, Box 102, 230 53, Alnarp, Sweden
| | - Ylva Hillbur
- Swedish University of Agricultural Sciences, Department of Plant Protection Biology, Unit of Chemical Ecology, Box 102, 230 53, Alnarp, Sweden
| | - Rickard Ignell
- Swedish University of Agricultural Sciences, Department of Plant Protection Biology, Unit of Chemical Ecology, Box 102, 230 53, Alnarp, Sweden
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12
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Mignotte A, Garros C, Gardès L, Balenghien T, Duhayon M, Rakotoarivony I, Tabourin L, Poujol L, Mathieu B, Ibañez-Justicia A, Deniz A, Cvetkovikj A, Purse BV, Ramilo DW, Stougiou D, Werner D, Pudar D, Petrić D, Veronesi E, Jacobs F, Kampen H, Pereira da Fonseca I, Lucientes J, Navarro J, de la Puente JM, Stefanovska J, Searle KR, Khallaayoune K, Culverwell CL, Larska M, Bourquia M, Goffredo M, Bisia M, England M, Robin M, Quaglia M, Miranda-Chueca MÁ, Bødker R, Estrada-Peña R, Carpenter S, Tchakarova S, Boutsini S, Sviland S, Schäfer SM, Ozoliņa Z, Segliņa Z, Vatansever Z, Huber K. The tree that hides the forest: cryptic diversity and phylogenetic relationships in the Palaearctic vector Obsoletus/Scoticus Complex (Diptera: Ceratopogonidae) at the European level. Parasit Vectors 2020; 13:265. [PMID: 32434592 PMCID: PMC7238629 DOI: 10.1186/s13071-020-04114-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/29/2020] [Indexed: 11/27/2022] Open
Abstract
Background Culicoides obsoletus is an abundant and widely distributed Holarctic biting midge species, involved in the transmission of bluetongue virus (BTV) and Schmallenberg virus (SBV) to wild and domestic ruminants. Females of this vector species are often reported jointly with two morphologically very close species, C. scoticus and C. montanus, forming the Obsoletus/Scoticus Complex. Recently, cryptic diversity within C. obsoletus was reported in geographically distant sites. Clear delineation of species and characterization of genetic variability is mandatory to revise their taxonomic status and assess the vector role of each taxonomic entity. Our objectives were to characterize and map the cryptic diversity within the Obsoletus/Scoticus Complex. Methods Portion of the cox1 mitochondrial gene of 3763 individuals belonging to the Obsoletus/Scoticus Complex was sequenced. Populations from 20 countries along a Palaearctic Mediterranean transect covering Scandinavia to Canary islands (North to South) and Canary islands to Turkey (West to East) were included. Genetic diversity based on cox1 barcoding was supported by 16S rDNA mitochondrial gene sequences and a gene coding for ribosomal 28S rDNA. Species delimitation using a multi-marker methodology was used to revise the current taxonomic scheme of the Obsoletus/Scoticus Complex. Results Our analysis showed the existence of three phylogenetic clades (C. obsoletus clade O2, C. obsoletus clade dark and one not yet named and identified) within C. obsoletus. These analyses also revealed two intra-specific clades within C. scoticus and raised questions about the taxonomic status of C. montanus. Conclusions To our knowledge, our study provides the first genetic characterization of the Obsoletus/Scoticus Complex on a large geographical scale and allows a revision of the current taxonomic classification for an important group of vector species of livestock viruses in the Palaearctic region.![]()
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Affiliation(s)
- Antoine Mignotte
- ASTRE, Univ Montpellier, Cirad, INRAE, Montpellier, France. .,Cirad, UMR ASTRE, 34398, Montpellier, France.
| | - Claire Garros
- ASTRE, Univ Montpellier, Cirad, INRAE, Montpellier, France. .,Cirad, UMR ASTRE, 34398, Montpellier, France.
| | - Laetitia Gardès
- ASTRE, Univ Montpellier, Cirad, INRAE, Montpellier, France.,Cirad, UMR ASTRE, 97170, Petit-Bourg, Guadeloupe, France
| | - Thomas Balenghien
- ASTRE, Univ Montpellier, Cirad, INRAE, Montpellier, France.,Cirad, UMR ASTRE, 34398, Montpellier, France.,Institut Agronomique et Vétérinaire Hassan II, Unité Parasitologie et Maladies Parasitaires, 10100, Rabat, Morocco
| | - Maxime Duhayon
- ASTRE, Univ Montpellier, Cirad, INRAE, Montpellier, France.,Cirad, UMR ASTRE, 34398, Montpellier, France
| | - Ignace Rakotoarivony
- ASTRE, Univ Montpellier, Cirad, INRAE, Montpellier, France.,Cirad, UMR ASTRE, 34398, Montpellier, France
| | - Laura Tabourin
- ASTRE, Univ Montpellier, Cirad, INRAE, Montpellier, France.,Cirad, UMR ASTRE, 34398, Montpellier, France
| | - Léa Poujol
- ASTRE, Univ Montpellier, Cirad, INRAE, Montpellier, France.,Cirad, UMR ASTRE, 34398, Montpellier, France
| | - Bruno Mathieu
- Institute of Parasitology and Tropical Pathology of Strasbourg, Université de Strasbourg, DIHP UR 7292, 67000, Strasbourg, France
| | - Adolfo Ibañez-Justicia
- Centre for Monitoring of Vectors, National Reference Centre, Netherlands Food and Consumer Product Safety Authority, Wageningen, The Netherlands
| | - Ahmet Deniz
- Veterinary Control Central Research Institute, Ankara, Turkey
| | - Aleksandar Cvetkovikj
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, Ss. Cyril and Methodius University in Skopje, Skopje, Republic of North Macedonia
| | - Bethan V Purse
- Centre for Ecology, Centre for Ecology & Hydrology, Wallingford, OX10 8BB, UK
| | - David W Ramilo
- CIISA-Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal
| | - Despoina Stougiou
- Department of Parasitology-Parasitic Diseases, Entomology & Bee Health, Veterinary Centre of Athens, Athens, Greece
| | - Doreen Werner
- Leibniz-Centre for Agricultural Landscape Research, Müncheberg, Germany
| | - Dubravka Pudar
- Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia
| | - Dušan Petrić
- Faculty of Agriculture, University of Novi Sad, Novi Sad, Serbia
| | - Eva Veronesi
- National Centre for Vector Entomology, Institute of Parasitology, University of Zürich, Zürich, Switzerland
| | - Frans Jacobs
- Centre for Monitoring of Vectors, National Reference Centre, Netherlands Food and Consumer Product Safety Authority, Wageningen, The Netherlands
| | - Helge Kampen
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald, Germany
| | - Isabel Pereira da Fonseca
- CIISA-Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477, Lisboa, Portugal
| | - Javier Lucientes
- Department of Animal Pathology, AgriFood Institute of Aragón (IA2) Veterinary Faculty, 50013, Zaragoza, Spain
| | - Javier Navarro
- Departamento de Microbiología, Laboratorio de Producción y Sanidad Animal de Granada, Junta de Andalucía, Granada, Spain
| | - Josue Martinez de la Puente
- Doñana Biological Station, CSIC, Sevilla, Spain.,Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Jovana Stefanovska
- Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, Ss. Cyril and Methodius University in Skopje, Skopje, Republic of North Macedonia
| | - Kate R Searle
- Centre for Ecology & Hydrology, Edinburgh, OX10 8BB, UK
| | - Khalid Khallaayoune
- Institut Agronomique et Vétérinaire Hassan II, Unité Parasitologie et Maladies Parasitaires, 10100, Rabat, Morocco
| | - C Lorna Culverwell
- Department of Virology, University of Helsinki, Medicum, Haartmaninkatu 3, Helsinki, 00014, Finland
| | | | - Maria Bourquia
- Cirad, UMR ASTRE, 34398, Montpellier, France.,Institut Agronomique et Vétérinaire Hassan II, Unité Parasitologie et Maladies Parasitaires, 10100, Rabat, Morocco
| | - Maria Goffredo
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Campo Boario, 64100, Teramo, Italy
| | - Marina Bisia
- Department of Parasitology-Parasitic Diseases, Entomology & Bee Health, Veterinary Centre of Athens, Athens, Greece
| | | | - Matthew Robin
- Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Leahurst, Chester High Road, Neston, Cheshire, CH64 7TE, UK
| | - Michela Quaglia
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Campo Boario, 64100, Teramo, Italy
| | - Miguel Ángel Miranda-Chueca
- Applied Zoology and Animal Conservation Research Group, University of the Balearic Islands UIB, Palma, Spain
| | - René Bødker
- University of Copenhagen, Copenhagen, Denmark
| | - Rosa Estrada-Peña
- Department of Animal Pathology, AgriFood Institute of Aragón (IA2) Veterinary Faculty, 50013, Zaragoza, Spain
| | | | - Simona Tchakarova
- National Diagnostic and Research Veterinary Medical Institute, Sofia, Bulgaria
| | - Sofia Boutsini
- Department of Parasitology-Parasitic Diseases, Entomology & Bee Health, Veterinary Centre of Athens, Athens, Greece
| | | | - Stefanie M Schäfer
- Centre for Ecology, Centre for Ecology & Hydrology, Wallingford, OX10 8BB, UK
| | - Zanda Ozoliņa
- Institute of Food safety, Animal Health and Environment 'BIOR', Riga, Latvia
| | - Zanda Segliņa
- Institute of Food safety, Animal Health and Environment 'BIOR', Riga, Latvia
| | - Zati Vatansever
- Veterinary Control Central Research Institute, Ankara, Turkey
| | - Karine Huber
- ASTRE, Univ Montpellier, Cirad, INRAE, Montpellier, France
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Yanase T, Murota K, Hayama Y. Endemic and Emerging Arboviruses in Domestic Ruminants in East Asia. Front Vet Sci 2020; 7:168. [PMID: 32318588 PMCID: PMC7154088 DOI: 10.3389/fvets.2020.00168] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 03/10/2020] [Indexed: 02/04/2023] Open
Abstract
Epizootic congenital abnormalities caused by Akabane, Aino, and Chuzan viruses have damaged the reproduction of domestic ruminants in East Asia for many years. In the past, large outbreaks of febrile illness related to bovine ephemeral fever and Ibaraki viruses severely affected the cattle industry in that region. In recent years, vaccines against these viruses have reduced the occurrence of diseases, although the viruses are still circulating and have occasionally caused sporadic and small-scaled epidemics. Over a long-term monitoring period, many arboviruses other than the above-mentioned viruses have been isolated from cattle and Culicoides biting midges in Japan. Several novel arboviruses that may infect ruminants (e.g., mosquito- and tick-borne arboviruses) were recently reported in mainland China based on extensive surveillance. It is noteworthy that some are suspected of being associated with cattle diseases. Malformed calves exposed to an intrauterine infection with orthobunyaviruses (e.g., Peaton and Shamonda viruses) have been observed. Epizootic hemorrhagic disease virus serotype 6 caused a sudden outbreak of hemorrhagic disease in cattle in Japan. Unfortunately, the pathogenicity of many other viruses in ruminants has been uncertain, although these viruses potentially affect livestock production. As global transportation grows, the risk of an accidental incursion of arboviruses is likely to increase in previously non-endemic areas. Global warming will also certainly affect the distribution and active period of vectors, and thus the range of virus spreads will expand to higher-latitude regions. To prevent anticipated damages to the livestock industry, the monitoring system for arboviral circulation and incursion should be strengthened; moreover, the sharing of information and preventive strategies will be essential in East Asia.
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Affiliation(s)
- Tohru Yanase
- Kyushu Research Station, National Institute of Animal Health, NARO, Kagoshima, Japan
| | - Katsunori Murota
- Kyushu Research Station, National Institute of Animal Health, NARO, Kagoshima, Japan
| | - Yoko Hayama
- Viral Disease and Epidemiology Research Division, National Institute of Animal Health, NARO, Tsukuba, Japan
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14
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Federici V, Goffredo M, Mancini G, Quaglia M, Santilli A, Di Nicola F, De Ascentis M, Cabras P, Volpicelli C, De Liberato C, Satta G, Federico G, Leone A, Pisciella M, Portanti O, Pizzurro F, Teodori L, Savini G. Vector Competence of Italian Populations of Culicoides for Some Bluetongue Virus Strains Responsible for Recent Northern African and European Outbreaks. Viruses 2019; 11:E941. [PMID: 31614799 PMCID: PMC6832517 DOI: 10.3390/v11100941] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/08/2019] [Accepted: 10/09/2019] [Indexed: 12/15/2022] Open
Abstract
The distribution of Bluetongue virus (BTV) in Europe can be represented by two distinct and interconnected epidemiological systems (episystems), each characterized by different ecological characteristics and vector species. This study investigated the vector competence of Italian populations of Culicoides imicola and Culicoides obsoletus/scoticus to some representative BTV strains after artificial oral infection. The BTV strains were selected according to their ability to spread to one or both episystems and included BTV-4 ITA, responsible of the recent Italian and French BTV-4 outbreaks; the BTV-2 strain which caused the first BTV incursion in Italy, Corsica, and Balearic Islands; BTV-4 MOR, responsible for the epidemic in Morocco; and BTV-8, the strain which spread through Europe between 2006 and 2008. Blood-soaked cotton pledgets and Hemotek membrane feeder using Parafilm® membrane were used to artificially feed midges. For each population/strain, recovery rates (positive/tested heads) were evaluated using serogroup- and serotype-specific RT-PCR. The trial demonstrated that, except for the Abruzzo population of C. obsoletus/C. scoticus, which was refractory to BTV-4 MOR infection, all the investigated Culicoides populations are susceptible to the selected BTV strains and that, if prompt vaccination programs and restriction measures had not been implemented, BTV-2 and BTV-4 MOR could have spread all over Europe.
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Affiliation(s)
- Valentina Federici
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Maria Goffredo
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Giuseppe Mancini
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Michela Quaglia
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Adriana Santilli
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Francesca Di Nicola
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Matteo De Ascentis
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Pierangela Cabras
- Istituto Zooprofilattico Sperimentale della Sardegna, Via Duca degli Abruzzi 8, 07100 Sassari, Italy.
| | - Carmela Volpicelli
- Azienda Sanitaria Provinciale Crotone, Via M. Nicoletta, 88900 Crotone (KR), Italy.
| | - Claudio De Liberato
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana, Via Appia Nuova 1411, 00178 Rome, Italy.
| | - Giuseppe Satta
- Istituto Zooprofilattico Sperimentale della Sardegna, Via Duca degli Abruzzi 8, 07100 Sassari, Italy.
| | - Giovanni Federico
- Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Figurella, 89135 Catona (RC), Italy.
| | - Alessandra Leone
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Maura Pisciella
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Ottavio Portanti
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Federica Pizzurro
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Liana Teodori
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
| | - Giovanni Savini
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale', Via Campo Boario, 64100 Teramo, Italy.
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15
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Quantifying the potential for bluetongue virus transmission in Danish cattle farms. Sci Rep 2019; 9:13466. [PMID: 31530858 PMCID: PMC6749064 DOI: 10.1038/s41598-019-49866-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/26/2019] [Indexed: 11/30/2022] Open
Abstract
We used a mechanistic transmission model to estimate the number of infectious bites (IBs) generated per bluetongue virus (BTV) infected host (cattle) using estimated hourly microclimatic temperatures at 22,004 Danish cattle farms for the period 2000–2016, and Culicoides midge abundance based on 1,453 light-trap collections during 2007–2016. We used a range of published estimates of the duration of the hosts’ infectious period and equations for the relationship between temperature and four key transmission parameters: extrinsic incubation period, daily vector survival rate, daily vector biting rate and host-to-vector transmission rate resulting in 147,456 combinations of daily IBs. More than 82% combinations of the parameter values predicted > 1 IBs per host. The mean IBs (10–90th percentiles) for BTV per infectious host were 59 (0–73) during the transmission period. We estimated a maximum of 14,954 IBs per infectious host at some farms, while a best-case scenario suggested transmission was never possible at some farms. The use of different equations for the vector survival rate and host-to-vector transmission rates resulted in large uncertainty in the predictions. If BTV is introduced in Denmark, local transmission is very likely to occur. Vectors infected as late as mid-September (early autumn) can successfully transmit BTV to a new host until mid-November (late autumn).
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16
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Yanase T, Kato T, Hayama Y, Shirafuji H, Yamakawa M, Tanaka S. Oral Susceptibility of Japanese Culicoides (Diptera: Ceratopogonidae) Species to Akabane Virus. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:533-539. [PMID: 30418597 DOI: 10.1093/jme/tjy201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Indexed: 06/09/2023]
Abstract
To test their virus susceptibility and capacity as transmission vectors, Japanese Culicoides species were artificially fed a mixture of Akabane virus (AKAV) and bovine blood, and virus recovery was attempted from infected midges 9-11 d post-exposure. Culicoides tainanus, C. punctatus, C. humeralis, C. jacobsoni, C. oxystoma, and C. asiana were found to be orally susceptible to AKAV. Virus titers in single infected midges of C. tainanus, C. oxystoma, C. punctatus, and C. jacobsoni ranged from 100.75 to 104.0 TCID50 (tissue culture infectious dose). The titers in the infected C. oxystoma were significantly higher than those in the other infected species. Viral RNA was detected from both midges testing positive and those testing negative for infectious virus particles, but the viral RNA copies in the infectious virus-negative midges were significantly lower than those in the infectious virus-positive midges. Lower viral amplification, limited dissemination or both caused by tissue barriers might occur in infected midges from which infectious viruses were undetectable. A fully disseminated infection was developed in orally infected C. oxystoma and C. tainanus. This finding indicates their capacity to transmit AKAV, assuming that salivary gland barriers have limited effects on viral entry to and replication in salivary gland tissue. This result also suggests that the other orally susceptible species are potentially competent for AKAV transmission and would be considered active vectors of its spread.
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Affiliation(s)
- Tohru Yanase
- Kyushu Research Station, National Institute of Animal Health, NARO, Chuzan, Kagoshima, Japan
| | - Tomoko Kato
- Kyushu Research Station, National Institute of Animal Health, NARO, Chuzan, Kagoshima, Japan
| | - Yoko Hayama
- Viral Disease and Epidemiology Research Division, National Institute of Animal Health, NARO, Kannondai, Tsukuba, Ibaraki, Japan
| | - Hiroaki Shirafuji
- Kyushu Research Station, National Institute of Animal Health, NARO, Chuzan, Kagoshima, Japan
| | - Makoto Yamakawa
- Kyushu Research Station, National Institute of Animal Health, NARO, Chuzan, Kagoshima, Japan
| | - Shogo Tanaka
- Kyushu Research Station, National Institute of Animal Health, NARO, Chuzan, Kagoshima, Japan
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17
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Möhlmann TWR, Oymans J, Wichgers Schreur PJ, Koenraadt CJM, Kortekaas J, Vogels CBF. Vector competence of biting midges and mosquitoes for Shuni virus. PLoS Negl Trop Dis 2019; 13:e0006609. [PMID: 30753187 PMCID: PMC6372163 DOI: 10.1371/journal.pntd.0006609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 06/13/2018] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Shuni virus (SHUV) is an orthobunyavirus that belongs to the Simbu serogroup. SHUV was isolated from diverse species of domesticated animals and wildlife, and is associated with neurological disease, abortions, and congenital malformations. Recently, SHUV caused outbreaks among ruminants in Israel, representing the first incursions outside the African continent. The isolation of SHUV from a febrile child in Nigeria and seroprevalence among veterinarians in South Africa suggests that the virus may have zoonotic potential as well. The high pathogenicity, extremely broad tropism, potential transmission via both biting midges and mosquitoes, and zoonotic features of SHUV require further investigation. This is important to accurately determine the risk for animal and human health, and to facilitate preparations for potential epidemics. To gain first insight into the potential involvement of biting midges and mosquitoes in SHUV transmission we have investigated the ability of SHUV to infect two species of laboratory-colonised biting midges and two species of mosquitoes. METHODOLOGY/PRINCIPAL FINDINGS Culicoides nubeculosus, C. sonorensis, Culex pipiens pipiens, and Aedes aegypti were orally exposed to SHUV by providing an infectious blood meal. Biting midges showed high infection rates of approximately 40%-60%, whereas infection rates of mosquitoes were only 0-2%. Moreover, successful dissemination in both species of biting midges and no evidence for transmission by orally exposed mosquitoes was found. CONCLUSIONS/SIGNIFICANCE The results of this study suggest that different species of Culicoides midges are efficient in SHUV transmission, while the involvement of mosquitoes has not been supported.
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Affiliation(s)
- Tim W. R. Möhlmann
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
- * E-mail:
| | - Judith Oymans
- Department of Virology, Wageningen Bioveterinary Research, Wageningen University & Research, Lelystad, The Netherlands
- Laboratory of Virology, Wageningen University & Research, Wageningen, The Netherlands
| | - Paul J. Wichgers Schreur
- Department of Virology, Wageningen Bioveterinary Research, Wageningen University & Research, Lelystad, The Netherlands
| | | | - Jeroen Kortekaas
- Department of Virology, Wageningen Bioveterinary Research, Wageningen University & Research, Lelystad, The Netherlands
- Laboratory of Virology, Wageningen University & Research, Wageningen, The Netherlands
| | - Chantal B. F. Vogels
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
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18
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Möhlmann TWR, Oymans J, Wichgers Schreur PJ, Koenraadt CJM, Kortekaas J, Vogels CBF. Vector competence of biting midges and mosquitoes for Shuni virus. PLoS Negl Trop Dis 2018; 12:e0006993. [PMID: 30532189 PMCID: PMC6285265 DOI: 10.1371/journal.pntd.0006993] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 11/12/2018] [Indexed: 01/08/2023] Open
Abstract
Background Shuni virus (SHUV) is an orthobunyavirus that belongs to the Simbu serogroup. SHUV was isolated from diverse species of domesticated animals and wildlife, and is associated with neurological disease, abortions, and congenital malformations. Recently, SHUV caused outbreaks among ruminants in Israel, representing the first incursions outside the African continent. The isolation of SHUV from a febrile child in Nigeria and seroprevalence among veterinarians in South Africa suggests that the virus may have zoonotic potential as well. The high pathogenicity, extremely broad tropism, potential transmission via both biting midges and mosquitoes, and zoonotic features warrants prioritization of SHUV for further research. Additional knowledge is essential to accurately determine the risk for animal and human health, and to assess the risk of future epizootics and epidemics. To gain first insights into the potential involvement of arthropod vectors in SHUV transmission, we have investigated the ability of SHUV to infect and disseminate in laboratory-reared biting midges and mosquitoes. Methodology/Principal findings Culicoides nubeculosus, C. sonorensis, Culex pipiens pipiens, and Aedes aegypti were orally exposed to SHUV by providing an infectious blood meal. Biting midges showed high infection rates of approximately 40–60%, whereas infection rates of mosquitoes were lower than 2%. SHUV successfully disseminated in both species of biting midges, but no evidence of transmission in orally exposed mosquitoes was found. Conclusions/Significance The results of this study show that different species of Culicoides biting midges are susceptible to infection and dissemination of SHUV, whereas the two mosquito species tested were found not to be susceptible. Arthropod-borne (arbo)viruses are notorious for causing unpredictable and large-scale epidemics and epizootics. Apart from viruses such as West Nile virus and Rift Valley fever virus that are well known to have a significant impact on human and animal health, many arboviruses remain neglected. Shuni virus (SHUV) is a neglected virus with zoonotic potential that was recently associated with severe disease in livestock and wildlife. Isolations of SHUV from field-collected biting midges and mosquitoes suggests that SHUV may be transmitted by these insects. Laboratory-reared biting midge species (Culicoides nubeculosus and C. sonorensis) and mosquito species (Culex pipiens pipiens and Aedes aegypti), that are known to transmit other arboviruses, were exposed to SHUV via an infectious blood meal. SHUV was able to successfully disseminate in both biting midge species, whereas no evidence of infection or transmission in both mosquito species was found. Our results show that SHUV infects and disseminates in two different Culicoides species, suggesting that these insects could play an important role in the disease transmission cycle.
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Affiliation(s)
- Tim W. R. Möhlmann
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
- * E-mail:
| | - Judith Oymans
- Department of Virology, Wageningen Bioveterinary Research, Wageningen University & Research, Lelystad, The Netherlands
- Laboratory of Virology, Wageningen University & Research, Wageningen, The Netherlands
| | - Paul J. Wichgers Schreur
- Department of Virology, Wageningen Bioveterinary Research, Wageningen University & Research, Lelystad, The Netherlands
| | | | - Jeroen Kortekaas
- Department of Virology, Wageningen Bioveterinary Research, Wageningen University & Research, Lelystad, The Netherlands
- Laboratory of Virology, Wageningen University & Research, Wageningen, The Netherlands
| | - Chantal B. F. Vogels
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
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Pudar D, Petrić D, Allène X, Alten B, Ayhan N, Cvetkovikj A, Garros C, Goletić T, Gunay F, Hlavackova K, Ćupina AI, Kavran M, Lestinova T, Mathieu B, Mikov O, Pajović I, Rakotoarivony I, Stefanovska J, Vaselek S, Zuko A, Balenghien T. An update of the Culicoides (Diptera: Ceratopogonidae) checklist for the Balkans. Parasit Vectors 2018; 11:462. [PMID: 30103828 PMCID: PMC6088421 DOI: 10.1186/s13071-018-3051-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 08/03/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The prime significance of species belonging to the genus Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) is their ability to transmit viruses such as bluetongue virus (BTV) to wild and domestic ruminants. Prior to 1998, BTV was considered exotic in Europe, but according to recent history of its outbreaks, it has become endemic in southern and eastern European countries circulating beyond its expected historical limits, into the Balkan region. The wind-borne long-distance dispersal of Culicoides spp. over water bodies and local spreading between farms emphasize the necessity of filling in the information gaps regarding vector species distribution. In most Balkan countries, data on Culicoides fauna and species distribution are lacking, or information is old and scarce. RESULTS During this study, 8586 specimens belonging to 41 species were collected. We present the first faunistic data on Culicoides species in the former Yugoslav Republic of Macedonia (FYROM), Kosovo, Montenegro and Serbia. For other countries (Bosnia and Herzegovina, Bulgaria and Croatia), all historical records were compiled for the first time and then expanded with our findings to various extents. In all countries, confirmed or suspected BTV vector species belonging to the subgenera Avaritia and Culicoides were collected. The total number of species sampled during our field collections was 20 in Bosnia and Herzegovina (15 new records), 10 in Bulgaria (2 new records), 10 in Croatia (5 new records), 13 in FYROM, 9 in Kosovo, 15 in Montenegro, and 28 in Serbia. Of these, 14 species were registered for the first time in this part of the Balkans. CONCLUSIONS This paper provides the first data about Culicoides fauna in FYROM, Kosovo, Montenegro and Serbia, as well as new records and an update on the checklists for Bosnia and Herzegovina, Bulgaria and Croatia. These findings provide preliminary insights into the routes of BTV introduction and spreading within the Balkans, and present a valuable contribution to further research related to Culicoides-borne diseases in Europe.
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Affiliation(s)
- Dubravka Pudar
- Faculty of Agriculture, Department of Phytomedicine and Plant Protection, Laboratory for Medical and Veterinary Entomology, University of Novi Sad, Novi Sad, Serbia
| | - Dušan Petrić
- Faculty of Agriculture, Department of Phytomedicine and Plant Protection, Laboratory for Medical and Veterinary Entomology, University of Novi Sad, Novi Sad, Serbia
| | - Xavier Allène
- CIRAD, UMR ASTRE, F-34398 Montpellier, France
- ASTRE, University Montpellier, CIRAD, INRA, Montpellier, France
| | - Bulent Alten
- Faculty of Science, Department of Biology, Ecology Division, VERG Laboratories, Hacettepe University, Beytepe-Ankara, Turkey
| | - Nazlı Ayhan
- Virology Unit, Faculty of Medicine, Aix-Marseille University, Marseille cedex 05, France
| | - Aleksandar Cvetkovikj
- Faculty of Veterinary Medicine, Department of Parasitology and Parasitic Diseases, Ss. Cyril and Methodius University in Skopje, Skopje, Republic of Macedonia
| | - Claire Garros
- CIRAD, UMR ASTRE, F-34398 Montpellier, France
- ASTRE, University Montpellier, CIRAD, INRA, Montpellier, France
- CIRAD, UMR ASTRE, F-97490 Sainte Clotilde, Réunion
| | - Teufik Goletić
- Veterinary Faculty, Department of Zootechnics and Poultry, University of Sarajevo, Sarajevo, Bosnia and Herzegovina
| | - Filiz Gunay
- Faculty of Science, Department of Biology, Ecology Division, VERG Laboratories, Hacettepe University, Beytepe-Ankara, Turkey
| | - Kristyna Hlavackova
- Faculty of Science, Department of Parasitology, Charles University in Prague, 2 Prague, Czech Republic
| | - Aleksandra Ignjatović Ćupina
- Faculty of Agriculture, Department of Phytomedicine and Plant Protection, Laboratory for Medical and Veterinary Entomology, University of Novi Sad, Novi Sad, Serbia
| | - Mihaela Kavran
- Faculty of Agriculture, Department of Phytomedicine and Plant Protection, Laboratory for Medical and Veterinary Entomology, University of Novi Sad, Novi Sad, Serbia
| | - Tereza Lestinova
- Faculty of Science, Department of Parasitology, Charles University in Prague, 2 Prague, Czech Republic
| | - Bruno Mathieu
- Medicine Faculty, Institute of Parasitology and Tropical Pathology, University of Strasbourg, EA7292 Strasbourg, France
| | - Ognyan Mikov
- National Centre of Infectious and Parasitic Diseases, Department of Parasitology and Tropical Medicine, Laboratory of Experimental and Applied Parasitology, Sofia, Bulgaria
| | - Igor Pajović
- Biotechnical Faculty, University of Montenegro, Podgorica, Montenegro
| | - Ignace Rakotoarivony
- CIRAD, UMR ASTRE, F-34398 Montpellier, France
- ASTRE, University Montpellier, CIRAD, INRA, Montpellier, France
| | - Jovana Stefanovska
- Faculty of Veterinary Medicine, Department of Parasitology and Parasitic Diseases, Ss. Cyril and Methodius University in Skopje, Skopje, Republic of Macedonia
| | - Slavica Vaselek
- Faculty of Agriculture, Department of Phytomedicine and Plant Protection, Laboratory for Medical and Veterinary Entomology, University of Novi Sad, Novi Sad, Serbia
| | - Almedina Zuko
- Veterinary Faculty, Department of Parasitology and Invasive Diseases, University of Sarajevo, Sarajevo, Bosnia and Herzegovina
| | - Thomas Balenghien
- CIRAD, UMR ASTRE, F-34398 Montpellier, France
- ASTRE, University Montpellier, CIRAD, INRA, Montpellier, France
- IAV Hassan II, MIMC unit, Rabat, Morocco
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Paslaru AI, Mathis A, Torgerson P, Veronesi E. Vector competence of pre-alpine Culicoides (Diptera: Ceratopogonidae) for bluetongue virus serotypes 1, 4 and 8. Parasit Vectors 2018; 11:466. [PMID: 30103803 PMCID: PMC6090685 DOI: 10.1186/s13071-018-3050-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 08/03/2018] [Indexed: 12/02/2022] Open
Abstract
Background Bluetongue disease, caused by bluetongue virus serotype 8 (BTV-8), appeared for the first time in the northern part of Europe in 2006, and subsequently rapidly spread causing severe economic losses to the farming industry. The implicated vectors of BTV in Europe are Culicoides species within the subgenus Avaritia (C. chiopterus, C. dewulfi, C. obsoletus and C. scoticus). Epidemiological data from Switzerland have shown that BTV, whose spread was eliminated at an early stage by vaccination campaigns, had not been circulating among livestock at higher altitudes where other species dominate the Culicoides fauna. In this study, we investigated the extent that Culicoides spp. prevailing at higher altitudes (mainly C. grisescens) can act as vectors for BTV. Methods Culicoides were collected at farms in the pre-alpine region (two sites at 1550 m above sea level, masl, referred to as pre-alpine I; one site at 2030 masl, pre-alpine II) and, for comparative purposes, from the Swiss Plateau (one site, 650 masl). They were fed on bovine blood/BTV suspensions (BTV-1, 4 or 8) and incubated for eight days under a fluctuating temperature regime (13–25 °C, mean 19 °C), reflecting a mid-summer warm spell in the pre-alpine region. Susceptibility to BTV transmission was assessed from head homogenates by RT-qPCR and virus isolation. Results Overall, 9196 female Culicoides were exposed to the three BTV strains through an artificial membrane, with feeding rates of 14–27%. Survival rates of blood-engorged Culicoides females at eight days post-infection depended on both virus serotype and altitude of origin. Virus dissemination (Cq ≤ the cut-off value as determined by serial virus dilutions) was confirmed only for BTV-1 in C. scoticus (dissemination efficiency 22.5%; 9/40) and C. obsoletus (5.6%; 1/18) from the Swiss Plateau area. There was no strong evidence of susceptibility to infection for Culicoides from the pre-alpine area when fed with all BTV strains (BTV-1, 4 and 8). Conclusions This study confirms the susceptibility of C. scoticus and C. obsoletus to BTV-1 infection, including under cooler temperatures. Culicoides grisescens, which is highly abundant at higher altitudes, cannot be considered a potential vector under these temperature conditions. Electronic supplementary material The online version of this article (10.1186/s13071-018-3050-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anca Ioana Paslaru
- National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland
| | - Alexander Mathis
- National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland
| | - Paul Torgerson
- Section of Epidemiology, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland
| | - Eva Veronesi
- National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland.
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Martinelle L, Dal Pozzo F, Thys C, De Leeuw I, Van Campe W, De Clercq K, Thiry E, Saegerman C. Assessment of cross-protection induced by a bluetongue virus (BTV) serotype 8 vaccine towards other BTV serotypes in experimental conditions. Vet Res 2018; 49:63. [PMID: 30012223 PMCID: PMC6048908 DOI: 10.1186/s13567-018-0556-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 06/25/2018] [Indexed: 02/06/2023] Open
Abstract
Bluetongue disease is caused by bluetongue virus (BTV) and BTV serotype 8 (BTV8) caused great economic damage in Europe during the last decade. From 1998 to 2007, in addition to BTV8, Europe had to face the emergence of BTV1, 2, 4, 9, and 16, spreading in countries where the virus has never been detected before. These unprecedented outbreaks trigger the need to evaluate and compare the clinical, virological and serological features of the European BTV serotypes in the local epidemiological context. In this study groups of calves were infected with one of the following European BTV serotypes, namely BTV1, 2, 4, 9 and 16. For each tested serotype, two groups of three male Holstein calves were used: one group vaccinated against BTV8, the other non-vaccinated. Clinical signs were quantified, viral RNA was detected in blood and organs and serological relationship was assessed. Calves were euthanized 35 days post-infection and necropsied. Most of the infected animals showed mild clinical signs. A partial serological cross reactivity has been reported between BTV8 and BTV4, and between BTV1 and BTV8. BTV2 and BTV4 viral RNA only reached low levels in blood, when compared to other serotypes, whereas in vitro growth assays could not highlight significant differences. Altogether the results of this study support the hypothesis of higher adaptation of some BTV strains to specific hosts, in this case calves. Furthermore, cross-protection resulting from a prior vaccination with BTV8 was highlighted based on cross-neutralization. However, the development of neutralizing antibodies is probably not totally explaining the mild protection induced by the heterologous vaccination.
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Affiliation(s)
- Ludovic Martinelle
- Faculty of Veterinary Medicine, Research Unit in Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULg), Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liege, Liege, Belgium
| | - Fabiana Dal Pozzo
- Faculty of Veterinary Medicine, Research Unit in Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULg), Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liege, Liege, Belgium
| | - Christine Thys
- Faculty of Veterinary Medicine, Research Unit in Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULg), Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liege, Liege, Belgium
| | | | | | | | - Etienne Thiry
- Faculty of Veterinary Medicine, Fundamental and Applied Research for Animal and Health (FARAH) Center, Veterinary Virology and Animal Viral Diseases, University of Liege, Liege, Belgium
| | - Claude Saegerman
- Faculty of Veterinary Medicine, Research Unit in Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULg), Fundamental and Applied Research for Animal and Health (FARAH) Center, University of Liege, Liege, Belgium.
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22
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Community analysis of the abundance and diversity of biting midge species (Diptera: Ceratopogonidae) in three European countries at different latitudes. Parasit Vectors 2018; 11:217. [PMID: 29587832 PMCID: PMC5872509 DOI: 10.1186/s13071-018-2792-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 03/11/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The outbreaks of bluetongue and Schmallenberg disease in Europe have increased efforts to understand the ecology of Culicoides biting midges and their role in pathogen transmission. However, most studies have focused on a specific habitat, region, or country. To facilitate wider comparisons, and to obtain a better understanding of the spread of disease through Europe, the present study focused on monitoring biting midge species diversity in three different habitat types and three countries across Europe. METHODS Biting midges were trapped using Onderstepoort Veterinary Institute light traps at a total of 27 locations in Sweden, the Netherlands and Italy, comprising farm, peri-urban and wetland habitats. From July 2014 to June 2015 all locations were sampled monthly, except for during the winter months. Trapped midges were counted and identified morphologically. Indices on species richness, evenness and diversity were calculated. Community compositions were analysed using non-metric multidimensional scaling (NMDS) techniques. RESULTS A total of 50,085 female midges were trapped during 442 collection nights. More than 88% of these belonged to the Obsoletus group. The highest midge diversity was found in Sweden, while species richness was highest in the Netherlands, and most specimens were trapped in Italy. For habitats within countries, diversity of the trapped midges was lowest for farms in all countries. Differences in biting midge species communities were more distinct across the three countries than the three habitat types. CONCLUSIONS A core midge community could be identified, in which the Obsoletus group was the most abundant. Variations in vector communities across countries imply different patterns of disease spread throughout Europe. How specific species and their associated communities affect disease risk is still unclear. Our results emphasize the importance of midge diversity data at community level, how this differs across large geographic range within Europe, and its implications on assessing risks of midge-borne disease outbreaks.
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23
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Talavera S, Muñoz-Muñoz F, Verdún M, Pujol N, Pagès N. Revealing potential bridge vectors for BTV and SBV: a study on Culicoides blood feeding preferences in natural ecosystems in Spain. MEDICAL AND VETERINARY ENTOMOLOGY 2018; 32:35-40. [PMID: 28857265 DOI: 10.1111/mve.12263] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 03/28/2017] [Accepted: 06/09/2017] [Indexed: 05/26/2023]
Abstract
Several species of Culicoides (Diptera: Ceratopogonidae) are vectors of pathogens, such as the bluetongue (BTV) and Schmallenberg (SBV) viruses, which cause important diseases in domestic and wild ruminants. As wild ruminants can contribute to overwintering and epizootics of both diseases, knowledge of the host-feeding behaviour of Culicoides in natural ecosystems is important to better understand their epidemiology. Blood-engorged Culicoides females trapped in natural areas inhabited by different wild ruminant species were genetically analysed to identify host species. The origin of bloodmeals was identified in 114 females of 14 species of Culicoides. A total of 104 (91.1%) Culicoides fed on mammals and 10 (8.9%) on birds. The most abundant host identified was red deer (66.7%), followed by humans (13%) and fallow deer (6.1%). Eleven of the 14 species of Culicoides fed exclusively on mammalian hosts. Among them, five are mammalophilic species considered to be important BTV and/or SBV vectors. The results of the present study confirm that Culicoides imicola, Culicoides obsoletus, Culicoides scoticus, Culicoides pulicaris and Culicoides punctatus fed on wild ruminants, and therefore support the hypothesis that these species can act as bridge vectors by facilitating the circulation of pathogens between wild and domestic ruminant communities.
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Affiliation(s)
- S Talavera
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Bellaterra, Spain
| | - F Muñoz-Muñoz
- Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - M Verdún
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Bellaterra, Spain
| | - N Pujol
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Bellaterra, Spain
| | - N Pagès
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Bellaterra, Spain
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24
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Cuéllar AC, Kjær LJ, Kirkeby C, Skovgard H, Nielsen SA, Stockmarr A, Andersson G, Lindstrom A, Chirico J, Lühken R, Steinke S, Kiel E, Gethmann J, Conraths FJ, Larska M, Hamnes I, Sviland S, Hopp P, Brugger K, Rubel F, Balenghien T, Garros C, Rakotoarivony I, Allène X, Lhoir J, Chavernac D, Delécolle JC, Mathieu B, Delécolle D, Setier-Rio ML, Venail R, Scheid B, Chueca MÁM, Barceló C, Lucientes J, Estrada R, Mathis A, Tack W, Bødker R. Spatial and temporal variation in the abundance of Culicoides biting midges (Diptera: Ceratopogonidae) in nine European countries. Parasit Vectors 2018; 11:112. [PMID: 29482593 PMCID: PMC5828119 DOI: 10.1186/s13071-018-2706-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 02/12/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are vectors of bluetongue virus (BTV), African horse sickness virus and Schmallenberg virus (SBV). Outbreaks of both BTV and SBV have affected large parts of Europe. The spread of these diseases depends largely on vector distribution and abundance. The aim of this analysis was to identify and quantify major spatial patterns and temporal trends in the distribution and seasonal variation of observed Culicoides abundance in nine countries in Europe. METHODS We gathered existing Culicoides data from Spain, France, Germany, Switzerland, Austria, Denmark, Sweden, Norway and Poland. In total, 31,429 Culicoides trap collections were available from 904 ruminant farms across these countries between 2007 and 2013. RESULTS The Obsoletus ensemble was distributed widely in Europe and accounted for 83% of all 8,842,998 Culicoides specimens in the dataset, with the highest mean monthly abundance recorded in France, Germany and southern Norway. The Pulicaris ensemble accounted for only 12% of the specimens and had a relatively southerly and easterly spatial distribution compared to the Obsoletus ensemble. Culicoides imicola Kieffer was only found in Spain and the southernmost part of France. There was a clear spatial trend in the accumulated annual abundance from southern to northern Europe, with the Obsoletus ensemble steadily increasing from 4000 per year in southern Europe to 500,000 in Scandinavia. The Pulicaris ensemble showed a very different pattern, with an increase in the accumulated annual abundance from 1600 in Spain, peaking at 41,000 in northern Germany and then decreasing again toward northern latitudes. For the two species ensembles and C. imicola, the season began between January and April, with later start dates and increasingly shorter vector seasons at more northerly latitudes. CONCLUSION We present the first maps of seasonal Culicoides abundance in large parts of Europe covering a gradient from southern Spain to northern Scandinavia. The identified temporal trends and spatial patterns are useful for planning the allocation of resources for international prevention and surveillance programmes in the European Union.
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Affiliation(s)
- Ana Carolina Cuéllar
- Division for Diagnostics and Scientific Advice, National Veterinary Institute, Technical University of Denmark (DTU), Copenhagen, Denmark.
| | - Lene Jung Kjær
- Division for Diagnostics and Scientific Advice, National Veterinary Institute, Technical University of Denmark (DTU), Copenhagen, Denmark
| | - Carsten Kirkeby
- Division for Diagnostics and Scientific Advice, National Veterinary Institute, Technical University of Denmark (DTU), Copenhagen, Denmark
| | - Henrik Skovgard
- Department of Agroecology - Entomology and Plant Pathology, Aarhus University, Aarhus, Denmark
| | - Søren Achim Nielsen
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
| | - Anders Stockmarr
- Department of Applied Mathematics and Computer Science, Technical University of Denmark (DTU), Copenhagen, Denmark
| | | | | | - Jan Chirico
- National Veterinary Institute (SVA), Uppsala, Sweden
| | - Renke Lühken
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research National Reference Centre for Tropical Infectious Diseases, Hamburg, Germany
| | - Sonja Steinke
- Department of Biology and Environmental Sciences, Carl von Ossietzky University, Oldenburg, Germany
| | - Ellen Kiel
- Department of Biology and Environmental Sciences, Carl von Ossietzky University, Oldenburg, Germany
| | - Jörn Gethmann
- Institute of Epidemiology, Friedrich Loeffler Institute, Greifswald, Germany
| | - Franz J Conraths
- Institute of Epidemiology, Friedrich Loeffler Institute, Greifswald, Germany
| | - Magdalena Larska
- Department of Virology, National Veterinary Research Institute, Pulawy, Poland
| | | | | | - Petter Hopp
- Norwegian Veterinary Institute, Oslo, Norway
| | | | - Franz Rubel
- Institute for Veterinary Public Health, Vetmeduni, Vienna, Austria
| | | | | | | | | | | | | | - Jean-Claude Delécolle
- Institute of Parasitology and Tropical Pathology of Strasbourg, EA7292, Université de Strasbourg, Strasbourg, France
| | - Bruno Mathieu
- Institute of Parasitology and Tropical Pathology of Strasbourg, EA7292, Université de Strasbourg, Strasbourg, France
| | - Delphine Delécolle
- Institute of Parasitology and Tropical Pathology of Strasbourg, EA7292, Université de Strasbourg, Strasbourg, France
| | | | - Roger Venail
- EID Méditerranée, Montpellier, France
- Avia-GIS NV, Zoersel, Belgium
| | | | | | - Carlos Barceló
- Laboratory of Zoology, University of the Balearic Islands, Palma de Mallorca, Spain
| | - Javier Lucientes
- Department of Animal Pathology, University of Zaragoza, Zaragoza, Spain
| | - Rosa Estrada
- Department of Animal Pathology, University of Zaragoza, Zaragoza, Spain
| | - Alexander Mathis
- Institute of Parasitology, University of Zürich, Zürich, Switzerland
| | | | - Rene Bødker
- Division for Diagnostics and Scientific Advice, National Veterinary Institute, Technical University of Denmark (DTU), Copenhagen, Denmark
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Barber J, Harrup LE, Silk R, Veronesi E, Gubbins S, Bachanek-Bankowska K, Carpenter S. Blood-feeding, susceptibility to infection with Schmallenberg virus and phylogenetics of Culicoides (Diptera: Ceratopogonidae) from the United Kingdom. Parasit Vectors 2018; 11:116. [PMID: 29486789 PMCID: PMC6389053 DOI: 10.1186/s13071-018-2650-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Accepted: 01/16/2018] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Culicoides biting midges (Diptera: Ceratopogonidae) are responsible for the biological transmission of internationally important arboviruses of livestock. In 2011, a novel Orthobunyavirus was discovered in northern Europe causing congenital malformations and abortions in ruminants. From field studies, Culicoides were implicated in the transmission of this virus which was subsequently named Schmallenberg virus (SBV), but to date no assessment of susceptibility to infection of field populations under standardised laboratory conditions has been carried out. We assessed the influence of membrane type (chick skin, collagen, Parafilm M®) when offered in conjunction with an artificial blood-feeding system (Hemotek, UK) on field-collected Culicoides blood-feeding rates. Susceptibility to infection with SBV following blood-feeding on an SBV-blood suspension provided via either (i) the Hemotek system or via (ii) a saturated cotton wool pledglet was then compared. Schmallenberg virus susceptibility was defined by RT-qPCR of RNA extractions of head homogenates and related to Culicoides species and haplotype identifications based on the DNA barcode region of the mitochondrial cytochrome c oxidase 1 (cox1) gene. RESULTS Culicoides blood-feeding rates were low across all membrane types tested (7.5% chick skin, 0.0% for collagen, 4.4% Parafilm M®, with 6029 female Culicoides being offered a blood meal in total). Susceptibility to infection with SBV through membrane blood-feeding (8 of 109 individuals tested) and pledglet blood-feeding (1 of 94 individuals tested) was demonstrated for the Obsoletus complex, with both C. obsoletus (Meigen) and C. scoticus Downes & Kettle susceptible to infection with SBV through oral feeding. Potential evidence of cryptic species within UK populations was found for the Obsoletus complex in phylogenetic analyses of cox1 DNA barcodes of 74 individuals assessed from a single field-site. CONCLUSIONS Methods described in this study provide the means to blood-feed Palaearctic Culicoides for vector competence studies and colonisation attempts. Susceptibility to SBV infection was 7.3% for membrane-fed members of the subgenus Avaritia and 1.1% for pledglet-fed. Both C. obsoletus and C. scoticus were confirmed as being susceptible to infection with SBV, with potential evidence of cryptic species within UK Obsoletus complex specimens, however the implications of cryptic diversity in the Obsoletus complex on arbovirus transmission remains unknown.
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Affiliation(s)
- James Barber
- Vector-borne Viral Disease Programme, The Pirbright Institute, Pirbright, Surrey, UK
| | - Lara E Harrup
- Vector-borne Viral Disease Programme, The Pirbright Institute, Pirbright, Surrey, UK
| | - Rhiannon Silk
- Vector-borne Viral Disease Programme, The Pirbright Institute, Pirbright, Surrey, UK
| | - Eva Veronesi
- Vector-borne Viral Disease Programme, The Pirbright Institute, Pirbright, Surrey, UK.,National Centre for Vector Entomology, Institute of Parasitology, University of Zürich, Winterthurerstr. 266a, 8057, Zürich, Switzerland
| | - Simon Gubbins
- Vector-borne Viral Disease Programme, The Pirbright Institute, Pirbright, Surrey, UK
| | | | - Simon Carpenter
- Vector-borne Viral Disease Programme, The Pirbright Institute, Pirbright, Surrey, UK.
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26
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Pagès N, Talavera S, Verdún M, Pujol N, Valle M, Bensaid A, Pujols J. Schmallenberg virus detection in Culicoides biting midges in Spain: First laboratory evidence for highly efficient infection of Culicoides of the Obsoletus complex and Culicoides imicola. Transbound Emerg Dis 2018; 65:e1-e6. [PMID: 28474491 DOI: 10.1111/tbed.12653] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Indexed: 11/30/2022]
Abstract
Since Schmallenberg disease was discovered in 2011, the disease rapidly spread across Europe. Culicoides biting midges have been implicated as putative Schmallenberg vectors in Europe. The detection of Schmallenberg virus (SBV) in field collected Culicoides was evaluated through retrospective (2011-2012) collections and captures performed in 2013. This study represents the first detection of SBV in field collected Culicoides in Spain. Infectious midges were detected at the foothills of Pyrenees, Aramunt, in the summer 2012. All the specimens infected with Schmallenberg were of the species Culicoides obsoletus s.s. confirming its putative vector status in Spain. Experimental infection on field collected Culicoides provided evidence of atypical high efficiency for SBV vector infection and transmission potential in local populations of Culicoides imicola and in Culicoides of the Obsoletus complex. However, captured individuals of C. imicola were more susceptible to SBV infection than C. obsoletus s.l. (p < .001), with an infection ratio of 0.94 and 0.63, respectively. In contrast, a Culicoides nubeculosus colony appeared to be refractory to SBV infection.
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Affiliation(s)
- N Pagès
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - S Talavera
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - M Verdún
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - N Pujol
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - M Valle
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - A Bensaid
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - J Pujols
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain
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Ségard A, Gardès L, Jacquier E, Grillet C, Mathieu B, Rakotoarivony I, Setier-Rio ML, Chavernac D, Cêtre-Sossah C, Balenghien T, Garros C. Schmallenberg virus in Culicoides
Latreille (Diptera: Ceratopogonidae) populations in France during 2011-2012 outbreak. Transbound Emerg Dis 2017; 65:e94-e103. [DOI: 10.1111/tbed.12686] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Indexed: 01/26/2023]
Affiliation(s)
- A. Ségard
- UMR ASTRE; CIRAD; Montpellier France
| | - L. Gardès
- UMR ASTRE; CIRAD; Montpellier France
| | | | | | - B. Mathieu
- IPPTS, DHPI EA 7292; Université de Strasbourg; Strasbourg France
| | | | | | | | - C. Cêtre-Sossah
- UMR ASTRE; CIRAD; Montpellier France
- UMR ASTRE; CIRAD; Sainte-Clotilde La Réunion France
| | - T. Balenghien
- UMR ASTRE; CIRAD; Montpellier France
- CIRAD; UMR ASTRE; Rabat Maroc
- Institut Agronomique et Vétérinaire Hassan II; Rabat Maroc
| | - C. Garros
- UMR ASTRE; CIRAD; Montpellier France
- UMR ASTRE; CIRAD; Sainte-Clotilde La Réunion France
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Evaluation of Host-Derived Volatiles for Trapping Culicoides Biting Midges (Diptera: Ceratopogonidae). J Chem Ecol 2017; 43:662-669. [PMID: 28674827 PMCID: PMC5557871 DOI: 10.1007/s10886-017-0860-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 05/09/2017] [Accepted: 06/19/2017] [Indexed: 02/03/2023]
Abstract
Culicoides biting midges (Diptera: Ceratopognidae) cause pain and distress through blood feeding, and transmit viruses that threaten both animal and human health worldwide. There are few effective tools for monitoring and control of biting midges, with semiochemical-based strategies offering the advantage of targeting host-seeking populations. In previous studies, we identified the host preference of multiple Culicoides species, including Culicoides impunctatus, as well as cattle-derived compounds that modulate the behavioral responses of C. nubeculosus under laboratory conditions. Here, we test the efficacy of these compounds, when released at different rates, in attracting C. impunctatus under field conditions in Southern Sweden. Traps releasing 1-octen-3-ol, decanal, phenol, 4-methylphenol or 3-propylphenol, when combined with carbon dioxide (CO2), captured significantly higher numbers of C. impunctatus compared to control traps baited with CO2 alone, with low release rates (0.1 mg h−1, 1 mg h−1) being generally more attractive. In contrast, traps releasing octanal or (E)-2-nonenal at 1 mg h−1 and 10 mg h−1 collected significantly lower numbers of C. impunctatus than control traps baited with CO2 only. Nonanal and 2-ethylhexanol did not affect the attraction of C. impunctatus when compared to CO2 alone at any of the release rates tested. The potential use of these semiochemicals as attractants and repellents for biting midge control is discussed.
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Talavera S, Muñoz-Muñoz F, Verdún M, Pagès N. Morphology and DNA barcoding reveal three species in one: description of Culicoides cryptipulicaris sp. nov. and Culicoides quasipulicaris sp. nov. in the subgenus Culicoides. MEDICAL AND VETERINARY ENTOMOLOGY 2017; 31:178-191. [PMID: 28370147 DOI: 10.1111/mve.12228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 10/27/2016] [Accepted: 11/10/2016] [Indexed: 06/07/2023]
Abstract
Species of the genus Culicoides (Diptera: Ceratopogonidae) are well known for their importance in the field of medical and veterinary entomology. Culicoides spp. transmit a wide variety of pathogens, primarily viruses that affect animals and humans. In Europe, the most economically important disease transmitted by Culicoides is bluetongue (BT). Culicoides spp. have been recently involved as primary vectors for Schmallenberg disease. The taxonomy within the subgenus Culicoides has been historically difficult and reorganizations have been proposed regularly. The subgenus Culicoides includes species that are considered to be potential vectors for BT. High morphological intraspecific variability has been attributed to these species. This highlights the apparent presence of previously undetected cryptic species diversity in the subgenus. In the present study, a detailed morphological and molecular study of specimens belonging to Culicoides pulicaris s.l. and specimens resembling a cross between C. pulicaris and Culicoides punctatus revealed the presence of two new species: Culicoides cryptipulicaris and Culicoides quasipulicaris. Females of C. quasipulicaris and males of both species were morphologically distinguished from C. pulicaris (Linnaeus, 1758), whereas females of C. cryptipulicaris were identified using molecular techniques exclusively.
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Affiliation(s)
- S Talavera
- Institut de Recerca i Tecnologia (IRTA), Centre de Recerca en Sanitat Animal (CReSA), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - F Muñoz-Muñoz
- Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - M Verdún
- Institut de Recerca i Tecnologia (IRTA), Centre de Recerca en Sanitat Animal (CReSA), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - N Pagès
- Institut de Recerca i Tecnologia (IRTA), Centre de Recerca en Sanitat Animal (CReSA), Universitat Autònoma de Barcelona, Barcelona, Spain
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Bessell PR, Searle KR, Auty HK, Handel IG, Purse BV, Bronsvoort BMDC. Assessing the potential for Bluetongue virus 8 to spread and vaccination strategies in Scotland. Sci Rep 2016; 6:38940. [PMID: 27958339 PMCID: PMC5154200 DOI: 10.1038/srep38940] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 11/16/2016] [Indexed: 12/11/2022] Open
Abstract
Europe has seen frequent outbreaks of Bluetongue (BT) disease since 2006, including an outbreak of BT virus serotype 8 in central France during 2015 that has continued to spread in Europe during 2016. Thus, assessing the potential for BTv-8 spread and determining the optimal deployment of vaccination is critical for contingency planning. We developed a spatially explicit mathematical model of BTv-8 spread in Scotland and explored the sensitivity of transmission to key disease spread parameters for which detailed empirical data is lacking. With parameters at mean values, there is little spread of BTv-8 in Scotland. However, under a “worst case” but still feasible scenario with parameters at the limits of their ranges and temperatures 1 °C warmer than the mean, we find extensive spread with 203,000 sheep infected given virus introduction to the south of Scotland between mid-May and mid-June. Strategically targeted vaccine interventions can greatly reduce BT spread. Specifically, despite BT having most clinical impact in sheep, we show that vaccination can have the greatest impact on reducing BTv infections in sheep when administered to cattle, which has implications for disease control policy.
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Affiliation(s)
- Paul R Bessell
- The Roslin Institute, The University of Edinburgh, Easter Bush, EH25 9RG, UK
| | - Kate R Searle
- Centre for Ecology and Hydrology, Edinburgh, EH26 0QB, UK
| | - Harriet K Auty
- Epidemiology Research Unit, Future Farming Systems Group, Scotland's Rural College (SRUC), An Lòchran, Inverness Campus, Inverness, IV2 5NA, UK
| | - Ian G Handel
- Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Easter Bush, EH25 9RG, UK
| | - Bethan V Purse
- Centre for Ecology and Hydrology, Wallingford, OX10 8BB, UK
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Foxi C, Delrio G, Falchi G, Marche MG, Satta G, Ruiu L. Role of different Culicoides vectors (Diptera: Ceratopogonidae) in bluetongue virus transmission and overwintering in Sardinia (Italy). Parasit Vectors 2016; 9:440. [PMID: 27502924 PMCID: PMC4977893 DOI: 10.1186/s13071-016-1733-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 07/28/2016] [Indexed: 11/25/2022] Open
Abstract
Background Bluetongue (BT) epidemics have affected the Mediterranean island of Sardinia since 2000. While Culicoides imicola represents the main bluetongue virus (BTV) vector, other European Culicoides biting midges, possibly implicated in virus transmission, have been detected here. Understanding their distribution, seasonal abundance, and infection rates is necessary to predict disease incidence and spread across coastal and inland areas, and to define their role in virus overwintering. Methods Biting midge abundance was determined by light traps on selected farms representing diverse climatic conditions of Sardinia. Livestock-associated Culicoides species were morphologically and molecularly identified. Infection rates in prevailing midge species captured in 2013 during a BTV-1 outbreak were determined using RT-qPCR based virus detection in insect body pools, supplemented by specific body region analyses. The seasonal infection prevalence in Culicoides samples collected in 2001 in a BTV-2 affected farm was also determined. Results The Newsteadi complex (C. newsteadi species A and species B) prevailed among all biting midge species (47.7 %), followed by C. imicola (27.8 %) and the Obsoletus complex (C. obsoletus and C. scoticus) (17.6 %). Whilst Culicoides imicola was more abundant along the coast, the Newsteadi complex was frequently collected at higher altitude and the Obsoletus complex was notably associated to cattle farms. Culicoides pulicaris and C. punctatus abundance was found to be marginal in all farms. BTV was detected in parous female samples of all these species, and the full dissemination of the virus within the body of C. imicola, C. obsoletus, C. scoticus, and Newsteadi complex species was confirmed by analyses of thorax and head, containing salivary glands. Higher infection rates were associated with C. scoticus, C. newsteadi species A and species B, compared to C. imicola. The virus was detected in C. newsteadi species A and C. obsoletus in winter and spring, whereas it was mainly found in summer and autumn in C. imicola. Conclusions In Sardinia, bluetongue virus is transmitted by multiple Culicoides vectors, including C. imicola and the Newsteadi complex being the most important. The Newsteadi complex and other midge species can play an important role in internal areas and are likely to be directly involved in virus overwintering.
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Affiliation(s)
- Cipriano Foxi
- Dipartimento di Agraria, University of Sassari, Via E. De Nicola, Sassari, Italy
| | - Gavino Delrio
- Dipartimento di Agraria, University of Sassari, Via E. De Nicola, Sassari, Italy
| | - Giovanni Falchi
- Dipartimento di Agraria, University of Sassari, Via E. De Nicola, Sassari, Italy
| | | | - Giuseppe Satta
- Istituto Zooprofilattico Sperimentale della Sardegna, Via Duca degli Abruzzi 8, Sassari, Italy
| | - Luca Ruiu
- Dipartimento di Agraria, University of Sassari, Via E. De Nicola, Sassari, Italy.
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Ruder MG, Lysyk TJ, Stallknecht DE, Foil LD, Johnson DJ, Chase CC, Dargatz DA, Gibbs EPJ. Transmission and Epidemiology of Bluetongue and Epizootic Hemorrhagic Disease in North America: Current Perspectives, Research Gaps, and Future Directions. Vector Borne Zoonotic Dis 2016; 15:348-63. [PMID: 26086556 DOI: 10.1089/vbz.2014.1703] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) are arthropod-transmitted viruses in the genus Orbivirus of the family Reoviridae. These viruses infect a variety of domestic and wild ruminant hosts, although the susceptibility to clinical disease associated with BTV or EHDV infection varies greatly among host species, as well as between individuals of the same species. Since their initial detection in North America during the 1950s, these viruses have circulated in endemic and epidemic patterns, with occasional incursions to more northern latitudes. In recent years, changes in the pattern of BTV and EHDV infection and disease have forced the scientific community to revisit some fundamental areas related to the epidemiology of these diseases, specifically in relation to virus-vector-host interactions and environmental factors that have potentially enabled the observed changes. The aim of this review is to identify research and surveillance gaps that obscure our understanding of BT and EHD in North America.
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Affiliation(s)
- Mark G Ruder
- 1 Arthropod-Borne Animal Diseases Research Unit, Agricultural Research Service , United States Department of Agriculture, Manhattan, Kansas
| | - Timothy J Lysyk
- 2 Research Centre , Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
| | - David E Stallknecht
- 3 Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia , Athens, Georgia
| | - Lane D Foil
- 4 Bob Jones Wildlife Research Institute, Louisiana State University Agcenter , Idlewild, Louisiana
| | - Donna J Johnson
- 5 National Veterinary Services Laboratories, Science, Technologies and Analysis Services (STAS), Veterinary Services, Animal and Plant Health Inspection Service , United States Department of Agriculture, Ames, Iowa
| | - Christopher C Chase
- 6 Department of Veterinary and Biomedical Sciences, South Dakota State University , Brookings, South Dakota
| | - David A Dargatz
- 7 Center for Epidemiology and Animal Health , STAS, Veterinary Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, Colorado
| | - E Paul J Gibbs
- 8 Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida , Gainesville, Florida
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Baker T, Carpenter S, Gubbins S, Newton R, Lo Iacono G, Wood J, Harrup LE. Can insecticide-treated netting provide protection for Equids from Culicoides biting midges in the United Kingdom? Parasit Vectors 2015; 8:604. [PMID: 26607993 PMCID: PMC4660720 DOI: 10.1186/s13071-015-1182-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/28/2015] [Indexed: 11/10/2022] Open
Abstract
Background Biting midges of the genus Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) cause a significant biting nuisance to equines and are responsible for the biological transmission of African horse sickness virus (AHSV). While currently restricted in distribution to sub-Saharan Africa, AHSV has a history of emergence into southern Europe and causes one of the most lethal diseases of horses and other species of Equidae. In the event of an outbreak of AHSV, the use of insecticide treated nets (ITNs) to screen equine accomodation is recommended by competent authorities including the Office International des Épizooties (OIE) in order to reduce vector-host contact. Methods Seven commercially avaliable pyrethroid insecticides and three repellent compounds, all of which are licensed for amateur use, were assessed in modified World Health Organization (WHO) cone bioassay trials in the laboratory using a colony line of Culicoides nubeculosus (Meigen), 1830. Two field trials were subsequently conducted to test the efficiency of treated net screens in preventing entry of Culicoides. Results A formulation of cypermethrin (0.15 % w/w) and pyrethrins (0.2 % w/w) (Tri-Tec 14®, LS Sales (Farnham) Ltd, Bloxham, UK) applied to black polyvinyl-coated polyester insect screen (1.6 mm aperture; 1.6 mm thickness) inflicted 100 % mortality on batches of C. nubeculosus following a three minute exposure in the WHO cone bioassays at 1, 7 and 14 days post-treatment. Tri-Tec 14® outperformed all other treatments tested and was subsequently selected for use in field trials. The first trial demonstrated that treated screens placed around an ultraviolet light-suction trap entirely prevented Culicoides being collected, despite their collection in identical traps with untreated screening or no screening. The second field trial examined entry of Culicoides into stables containing horses and found that while the insecticide treated screens reduced entry substantially, there was still a small risk of exposure to biting. Conclusions Screened stables can be utilised as part of an integrated control program in the event of an AHSV outbreak in order to reduce vector-host contact and may also be applicable to protection of horses from Culicoides during transport.
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Affiliation(s)
- Tiffany Baker
- University of Surrey, Guildford, Surrey, GU2 7XH, UK. .,Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK.
| | - Simon Carpenter
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK.
| | - Simon Gubbins
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK.
| | - Richard Newton
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, CB8 7UU, UK.
| | - Giovanni Lo Iacono
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.
| | - James Wood
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.
| | - Lara Ellen Harrup
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK.
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Talavera S, Muñoz-Muñoz F, Durán M, Verdún M, Soler-Membrives A, Oleaga Á, Arenas A, Ruiz-Fons F, Estrada R, Pagès N. Culicoides Species Communities Associated with Wild Ruminant Ecosystems in Spain: Tracking the Way to Determine Potential Bridge Vectors for Arboviruses. PLoS One 2015; 10:e0141667. [PMID: 26510136 PMCID: PMC4624870 DOI: 10.1371/journal.pone.0141667] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 10/11/2015] [Indexed: 01/04/2023] Open
Abstract
The genus Culicoides Latreille 1809 is a well-known vector for protozoa, filarial worms and, above all, numerous viruses. The Bluetongue virus (BTV) and the recently emerged Schmallenberg virus (SBV) are responsible for important infectious, non-contagious, insect-borne viral diseases found in domestic ruminants and transmitted by Culicoides spp. Both of these diseases have been detected in wild ruminants, but their role as reservoirs during the vector-free season still remains relatively unknown. In fact, we tend to ignore the possibility of wild ruminants acting as a source of disease (BTV, SBV) and permitting its reintroduction to domestic ruminants during the following vector season. In this context, a knowledge of the composition of the Culicoides species communities that inhabit areas where there are wild ruminants is of major importance as the presence of a vector species is a prerequisite for disease transmission. In this study, samplings were conducted in areas inhabited by different wild ruminant species; samples were taken in both 2009 and 2010, on a monthly basis, during the peak season for midge activity (in summer and autumn). A total of 102,693 specimens of 40 different species of the genus Culicoides were trapped; these included major BTV and SBV vector species. The most abundant vector species were C. imicola and species of the Obsoletus group, which represented 15% and 11% of total numbers of specimens, respectively. At the local scale, the presence of major BTV and SBV vector species in areas with wild ruminants coincided with that of the nearest sentinel farms included in the Spanish Bluetongue Entomological Surveillance Programme, although their relative abundance varied. The data suggest that such species do not exhibit strong host specificity towards either domestic or wild ruminants and that they could consequently play a prominent role as bridge vectors for different pathogens between both types of ruminants. This finding would support the hypothesis that wild ruminants could act as reservoirs for such pathogens, and subsequently be involved in the reintroduction of disease to livestock on neighbouring farms.
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Affiliation(s)
- Sandra Talavera
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA- UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain
- * E-mail:
| | - Francesc Muñoz-Muñoz
- Departament de Biologia Animal, de Biologia Vegetal i d’Ecologia, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain
| | - Mauricio Durán
- Health and Biotechnology (SaBio) group, Instituto de Investigación en Recursos Cinegéticos (IREC), Ciudad Real, Castilla la Mancha, Spain
| | - Marta Verdún
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA- UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain
| | - Anna Soler-Membrives
- Departament de Biologia Animal, de Biologia Vegetal i d’Ecologia, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain
| | - Álvaro Oleaga
- Health and Biotechnology (SaBio) group, Instituto de Investigación en Recursos Cinegéticos (IREC), Ciudad Real, Castilla la Mancha, Spain
- SERPA, Sociedad de Servicios del Principado de Asturias S.A., Gijón, Asturias, Spain
| | - Antonio Arenas
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Córdoba (UCO), Córdoba, Andalucía, Spain
| | - Francisco Ruiz-Fons
- Health and Biotechnology (SaBio) group, Instituto de Investigación en Recursos Cinegéticos (IREC), Ciudad Real, Castilla la Mancha, Spain
| | - Rosa Estrada
- Department of Animal Pathology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
| | - Nitu Pagès
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA- UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain
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Nielsen SA, Kristensen M. Delineation of Culicoides species by morphology and barcode exemplified by three new species of the subgenus Culicoides (Diptera: Ceratopogonidae) from Scandinavia. Parasit Vectors 2015; 8:151. [PMID: 25889579 PMCID: PMC4372322 DOI: 10.1186/s13071-015-0750-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 02/18/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Culicoides biting midges (Diptera: Ceratopogonidae) cause biting nuisance to livestock and humans and are vectors of a range of pathogens of medical and veterinary importance. Despite their economic significance, the delineation and identification of species where only morphology is considered, as well as the evolutionary relationships between species within this genus remains problematic. In recent years molecular barcoding has assisted substantially in the identification of biting midges in the multiple entomological survey projects which were initiated in many European countries following the bluetongue outbreak in 2006-2009. These studies revealed potentially new species and "species-complexes" with large genetic and morphological variability. Here we use molecular barcoding, together with morphological analysis, to study subgenus Culicoides Latreille from Scandinavia with focus on three potentially new species. METHODS Biting midges were collected at various sites in Denmark and Sweden. Culicoides specimens were described by variation of a fragment of their cytochrome c oxidase subunit 1 (COI) gene sequence and wing, palp and antennal characters. RESULTS It is shown that three new species initially separated by DNA barcoding with mitochondrial COI can be distinguished by morphological characters. In this context a key to Scandinavian subgenus Culicoides using wing and maxillary palp characters is presented. The key is including the three new species Culicoides boyi, Culicoides selandicus and Culicoides kalix. CONCLUSION Three new species of Culicoides biting midges were identified and could be identified by both molecular and morphological differences. Evaluation of differences between and within taxa of biting midges using COI barcode yielded a rough estimate of species delineation; interspecies differences across Culicoides subgenera approaches 20%, whereas intraspecies differences are below 4% and in most cases below 1%.
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Affiliation(s)
- Soren Achim Nielsen
- Department of Environmental, Social and Spatial Change, Roskilde University, 12.2, 4000, Roskilde, Denmark.
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Garros C, Balenghien T, Carpenter S, Delécolle JC, Meiswinkel R, Pédarrieu A, Rakotoarivony I, Gardès L, Golding N, Barber J, Miranda M, Borràs DB, Goffredo M, Monaco F, Pagès N, Sghaier S, Hammami S, Calvo JH, Lucientes J, Geysen D, De Deken G, Sarto I Monteys V, Schwenkenbecher J, Kampen H, Hoffmann B, Lehmann K, Werner D, Baldet T, Lancelot R, Cêtre-Sossah C. Towards the PCR-based identification of Palaearctic Culicoides biting midges (Diptera: Ceratopogonidae): results from an international ring trial targeting four species of the subgenus Avaritia. Parasit Vectors 2014; 7:223. [PMID: 24884950 PMCID: PMC4024274 DOI: 10.1186/1756-3305-7-223] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 04/28/2014] [Indexed: 01/11/2023] Open
Abstract
Background Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are biological vectors of internationally important arboviruses. To understand the role of Culicoides in the transmission of these viruses, it is essential to correctly identify the species involved. Within the western Palaearctic region, the main suspected vector species, C. obsoletus, C. scoticus, C. dewulfi and C. chiopterus, have similar wing patterns, which makes it difficult to separate and identify them correctly. Methods In this study, designed as an inter-laboratory ring trial with twelve partners from Europe and North Africa, we assess four PCR-based assays which are used routinely to differentiate the four species of Culicoides listed above. The assays based on mitochondrial or ribosomal DNA or microarray hybridisation were tested using aliquots of Culicoides DNA (extracted using commercial kits), crude lysates of ground specimens and whole Culicoides (265 individuals), and non-Culicoides Ceratopogonidae (13 individuals) collected from across Europe. Results A total of 800 molecular assays were implemented. The in-house assays functioned effectively, although specificity and sensitivity varied according to the molecular marker and DNA extraction method used. The Obsoletus group specificity was overall high (95-99%) while the sensitivity varied greatly (59.6-100%). DNA extraction methods impacted the sensitivity of the assays as well as the type of sample used as template for the DNA extraction. Conclusions The results are discussed in terms of current use of species diagnostic assays and the future development of molecular tools for the rapid differentiation of cryptic Culicoides species.
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Gubbins S, Turner J, Baylis M, van der Stede Y, van Schaik G, Abrahantes JC, Wilson AJ. Inferences about the transmission of Schmallenberg virus within and between farms. Prev Vet Med 2014; 116:380-90. [PMID: 24857371 PMCID: PMC4204990 DOI: 10.1016/j.prevetmed.2014.04.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 02/27/2014] [Accepted: 04/19/2014] [Indexed: 11/18/2022]
Abstract
In the summer of 2011 Schmallenberg virus (SBV), a Culicoides-borne orthobunyavirus, emerged in Germany and The Netherlands and subsequently spread across much of Europe. To draw inferences about the transmission of SBV we have developed two models to describe its spread within and between farms. The within-farm model was fitted to seroprevalence data for cattle and sheep farms in Belgium and The Netherlands, with parameters estimated using approximate Bayesian computation. Despite the short duration of viraemia in cattle and sheep (mean of 3–4 days) the within-farm seroprevalence can reach high levels (mean within-herd seroprevalence >80%), largely because the probability of transmission from host to vector is high (14%) and SBV is able to replicate quickly (0.03 per day-degree) and at relatively low temperatures (threshold for replication: 12.3 °C). Parameter estimates from the within-farm model were then used in a separate between-farm model to simulate the regional spread of SBV. This showed that the rapid spread of SBV at a regional level is primarily a consequence of the high probability of transmission from host to vector and the temperature requirements for virus replication. Our results, obtained for a region of the UK in a typical year with regard to animal movements, indicate that there is no need to invoke additional transmission mechanisms to explain the observed patterns of rapid spread of SBV in Europe. Moreover, the imposition of movement restrictions, even a total movement ban, has little effect on the spread of SBV at this scale.
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Affiliation(s)
- Simon Gubbins
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK.
| | - Joanne Turner
- Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Leahurst Campus, Chester High Road, Neston, Cheshire CH64 7TE, UK
| | - Matthew Baylis
- Department of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Leahurst Campus, Chester High Road, Neston, Cheshire CH64 7TE, UK
| | - Yves van der Stede
- Unit of Co-ordination Veterinary Diagnosis-Epidemiology and Risk Assessment, CODA-CERVA, Groeselenberg 99, 1180 Brussels, Belgium; Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | | | | | - Anthony J Wilson
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK
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Balenghien T, Pagès N, Goffredo M, Carpenter S, Augot D, Jacquier E, Talavera S, Monaco F, Depaquit J, Grillet C, Pujols J, Satta G, Kasbari M, Setier-Rio ML, Izzo F, Alkan C, Delécolle JC, Quaglia M, Charrel R, Polci A, Bréard E, Federici V, Cêtre-Sossah C, Garros C. The emergence of Schmallenberg virus across Culicoides communities and ecosystems in Europe. Prev Vet Med 2014; 116:360-9. [PMID: 24698329 DOI: 10.1016/j.prevetmed.2014.03.007] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 01/24/2014] [Accepted: 03/08/2014] [Indexed: 12/27/2022]
Abstract
Schmallenberg virus (SBV), a novel arboviral pathogen, has emerged and spread across Europe since 2011 inflicting congenital deformities in the offspring of infected adult ruminants. Several species of Culicoides biting midges (Diptera: Ceratopogonidae) have been implicated in the transmission of SBV through studies conducted in northern Europe. In this study Culicoides from SBV outbreak areas of mainland France and Italy (Sardinia) were screened for viral RNA. The role of both C. obsoletus and the Obsoletus complex (C. obsoletus and C. scoticus) in transmission of SBV were confirmed in France and SBV was also discovered in a pool of C. nubeculosus for the first time, implicating this species as a potential vector. While collections in Sardinia were dominated by C. imicola, only relatively small quantities of SBV RNA were detected in pools of this species and conclusive evidence of its potential role in transmission is required. In addition to these field-based studies, infection rates in colony-derived individuals of C. nubeculosus and field-collected C. scoticus are also examined in the laboratory. Rates of infection in C. nubeculosus were low, confirming previous studies, while preliminary examination of C. scoticus demonstrated that while this species can replicate SBV to a potentially transmissible level, further work is required to fully define comparative competence between species in the region. Finally, the oral competence for SBV of two abundant and widespread mosquito vector species in the laboratory is assessed. Neither Aedes albopictus nor Culex pipiens were demonstrated to replicate SBV to transmissible levels and appear unlikely to play a major role in transmission. Other vector competence data produced from studies across Europe to date is then comprehensively reviewed and compared with that generated previously for bluetongue virus.
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Affiliation(s)
- Thomas Balenghien
- Cirad, UMR15 CMAEE, F-34398 Montpellier, France; INRA, UMR1309 CMAEE, F-34398 Montpellier, France.
| | - Nonito Pagès
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra (Cerdanyola del Vallès), Spain
| | - Maria Goffredo
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Campo Boario, 64100 Teramo, Italy
| | - Simon Carpenter
- The Pirbright Institute, Ash Road, Woking, Surrey GU24 0NF, United Kingdom
| | - Denis Augot
- Université de Reims Champagne-Ardenne, ANSES, SFR Cap Santé, EA4688 - USC « VECPAR », Reims, France
| | - Elisabeth Jacquier
- Cirad, UMR15 CMAEE, F-34398 Montpellier, France; INRA, UMR1309 CMAEE, F-34398 Montpellier, France
| | - Sandra Talavera
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra (Cerdanyola del Vallès), Spain
| | - Federica Monaco
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Campo Boario, 64100 Teramo, Italy
| | - Jérôme Depaquit
- Université de Reims Champagne-Ardenne, ANSES, SFR Cap Santé, EA4688 - USC « VECPAR », Reims, France
| | - Colette Grillet
- Cirad, UMR15 CMAEE, F-34398 Montpellier, France; INRA, UMR1309 CMAEE, F-34398 Montpellier, France
| | - Joan Pujols
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra (Cerdanyola del Vallès), Spain
| | - Giuseppe Satta
- Istituto Zooprofilattico della Sardegna, Via Duca degli Abruzzi 8, Sardinia, Italy
| | - Mohamed Kasbari
- Université de Reims Champagne-Ardenne, ANSES, SFR Cap Santé, EA4688 - USC « VECPAR », Reims, France
| | | | - Francesca Izzo
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Campo Boario, 64100 Teramo, Italy
| | - Cigdem Alkan
- UMR_D 190 "Emergence des Pathologies Virales", Aix Marseille Univ, IRD French Institute of Research for Development, EHESP French School of Public Health, 13005 Marseille, France; IHU Mediterranee Infection, APHM Public Hospitals of Marseille, 13005 Marseille, France
| | | | - Michela Quaglia
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Campo Boario, 64100 Teramo, Italy
| | - Rémi Charrel
- UMR_D 190 "Emergence des Pathologies Virales", Aix Marseille Univ, IRD French Institute of Research for Development, EHESP French School of Public Health, 13005 Marseille, France; IHU Mediterranee Infection, APHM Public Hospitals of Marseille, 13005 Marseille, France
| | - Andrea Polci
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Campo Boario, 64100 Teramo, Italy
| | | | - Valentina Federici
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, Campo Boario, 64100 Teramo, Italy
| | - Catherine Cêtre-Sossah
- Cirad, UMR15 CMAEE, F-34398 Montpellier, France; INRA, UMR1309 CMAEE, F-34398 Montpellier, France
| | - Claire Garros
- Cirad, UMR15 CMAEE, F-34398 Montpellier, France; INRA, UMR1309 CMAEE, F-34398 Montpellier, France
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Pioz M, Guis H, Pleydell D, Gay E, Calavas D, Durand B, Ducrot C, Lancelot R. Did vaccination slow the spread of bluetongue in France? PLoS One 2014; 9:e85444. [PMID: 24465562 PMCID: PMC3897431 DOI: 10.1371/journal.pone.0085444] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 11/28/2013] [Indexed: 11/19/2022] Open
Abstract
Vaccination is one of the most efficient ways to control the spread of infectious diseases. Simulations are now widely used to assess how vaccination can limit disease spread as well as mitigate morbidity or mortality in susceptible populations. However, field studies investigating how much vaccines decrease the velocity of epizootic wave-fronts during outbreaks are rare. This study aimed at investigating the effect of vaccination on the propagation of bluetongue, a vector-borne disease of ruminants. We used data from the 2008 bluetongue virus serotype 1 (BTV-1) epizootic of southwest France. As the virus was newly introduced in this area, natural immunity of livestock was absent. This allowed determination of the role of vaccination in changing the velocity of bluetongue spread while accounting for environmental factors that possibly influenced it. The average estimated velocity across the country despite restriction on animal movements was 5.4 km/day, which is very similar to the velocity of spread of the bluetongue virus serotype 8 epizootic in France also estimated in a context of restrictions on animal movements. Vaccination significantly reduced the propagation velocity of BTV-1. In comparison to municipalities with no vaccine coverage, the velocity of BTV-1 spread decreased by 1.7 km/day in municipalities with immunized animals. For the first time, the effect of vaccination has been quantified using data from a real epizootic whilst accounting for environmental factors known to modify the velocity of bluetongue spread. Our findings emphasize the importance of vaccination in limiting disease spread across natural landscape. Finally, environmental factors, specifically those related to vector abundance and activity, were found to be good predictors of the velocity of BTV-1 spread, indicating that these variables need to be adequately accounted for when evaluating the role of vaccination on bluetongue spread.
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Affiliation(s)
- Maryline Pioz
- Unité Mixte de Recherche Contrôle des Maladies Animales Exotiques et Emergentes, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Montpellier, France
- Unité Mixte de Recherche 1309 Contrôle des Maladies Animales Exotiques et Emergentes, Institut National de la Recherche Agronomique (INRA), Montpellier, France
- * E-mail:
| | - Hélène Guis
- Unité Mixte de Recherche Contrôle des Maladies Animales Exotiques et Emergentes, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Montpellier, France
- Unité Mixte de Recherche 1309 Contrôle des Maladies Animales Exotiques et Emergentes, Institut National de la Recherche Agronomique (INRA), Montpellier, France
| | - David Pleydell
- Unité Mixte de Recherche 1309 Contrôle des Maladies Animales Exotiques et Emergentes, Institut National de la Recherche Agronomique (INRA), Petit-Bourg, Guadeloupe, France
- Unité Mixte de Recherche Contrôle des Maladies Animales Exotiques et Emergentes, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Petit-Bourg, Guadeloupe, France
| | - Emilie Gay
- Unité Epidémiologie, Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail (ANSES), Lyon, France
| | - Didier Calavas
- Unité Epidémiologie, Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail (ANSES), Lyon, France
| | - Benoît Durand
- Laboratoire Santé Animale, Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail (ANSES), Maisons-Alfort, France
| | - Christian Ducrot
- Unité de Recherche 346 d'Epidémiologie Animale, Institut National de la Recherche Agronomique (INRA), Saint Genès Champanelle, France
| | - Renaud Lancelot
- Unité Mixte de Recherche Contrôle des Maladies Animales Exotiques et Emergentes, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Montpellier, France
- Unité Mixte de Recherche 1309 Contrôle des Maladies Animales Exotiques et Emergentes, Institut National de la Recherche Agronomique (INRA), Montpellier, France
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Sensitivity of Culicoides obsoletus (Meigen) (Diptera: Ceratopogonidae) to deltamethrin determined by an adapted WHO standard susceptibility test. Parasitology 2013; 141:542-6. [PMID: 24476573 DOI: 10.1017/s0031182013001935] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Bluetongue is a disease of major economic concern in Europe. Its causative agent, bluetongue virus (BTV), is transmitted by several Culicoides species (mainly Culicoides imicola and Culicoides obsoletus in Europe). The application of insecticides on animals may reduce transmission of BTV, however, no formulation is currently licensed specifically against Culicoides midges. The present study assesses the susceptibility of C. obsoletus to deltamethrin using an adapted World Health Organization (WHO) susceptibility test. Midges were exposed to different dosages of deltamethrin for 1 h, and mortality after 1 h and 24 h was recorded. Results indicated that deltamethrin is highly toxic to C. obsoletus since a dose of 1·33×10(-4)% was enough to kill 50% of the population (LD50) in 24 h. The deltamethrin concentration needed to kill 90% of the population (LD90) was 5·55×10(-4)%. The results obtained in the present work could help to create a system that can be used to assess insecticide resistance and susceptibility of Culicoides biting midges.
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Charron MVP, Balenghien T, Seegers H, Langlais M, Ezanno P. How much can diptera-borne viruses persist over unfavourable seasons? PLoS One 2013; 8:e74213. [PMID: 24023929 PMCID: PMC3762737 DOI: 10.1371/journal.pone.0074213] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/29/2013] [Indexed: 11/19/2022] Open
Abstract
Diptera are vectors of major human and animal pathogens worldwide, such as dengue, West-Nile or bluetongue viruses. In seasonal environments, vector-borne disease occurrence varies with the seasonal variations of vector abundance. We aimed at understanding how diptera-borne viruses can persist for years under seasonal climates while vectors overwinter, which should stop pathogen transmission during winter. Modeling is a relevant integrative approach for investigating the large panel of persistence mechanisms evidenced through experimental and observational studies on specific biological systems. Inter-seasonal persistence of virus may occur in hosts due to viremia duration, chronic infection, or vertical transmission, in vector resistance stages, and due to a low continuous transmission in winter. Using a generic stochastic modeling framework, we determine the parameter ranges under which virus persistence could occur via these different mechanisms. The parameter ranges vary according to the host demographic regime: for a high host population turnover, persistence increases with the mechanism parameter, whereas for a low turnover, persistence is maximal for an optimal range of parameter. Persistence in hosts due to long viremia duration in a few hosts or due to vertical transmission is an effective strategy for the virus to overwinter. Unexpectedly, a low continuous transmission during winter does not give rise to certain persistence, persistence barely occurring for a low turnover of the susceptible population. We propose a generic framework adaptable to most diptera-borne diseases. This framework allows ones to assess the plausibility of each persistence mechanism in real epidemiological situations and to compare the range of parameter values theoretically allowing persistence with the range of values determined experimentally.
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Affiliation(s)
- Maud V. P. Charron
- UMR1300 Biologie, Epidémiologie et Analyse de Risques en santé animale, INRA, LUNAM Université, Oniris, Ecole nationale vétérinaire, agroalimentaire et de l’alimentation Nantes-Atlantique, Nantes, France
- UMR 5251, Université de Bordeaux, IMB, Bordeaux, France
- UMR 5251, CNRS, IMB, Talence, France
- * E-mail:
| | | | - Henri Seegers
- UMR1300 Biologie, Epidémiologie et Analyse de Risques en santé animale, INRA, LUNAM Université, Oniris, Ecole nationale vétérinaire, agroalimentaire et de l’alimentation Nantes-Atlantique, Nantes, France
| | - Michel Langlais
- UMR 5251, Université de Bordeaux, IMB, Bordeaux, France
- UMR 5251, CNRS, IMB, Talence, France
| | - Pauline Ezanno
- UMR1300 Biologie, Epidémiologie et Analyse de Risques en santé animale, INRA, LUNAM Université, Oniris, Ecole nationale vétérinaire, agroalimentaire et de l’alimentation Nantes-Atlantique, Nantes, France
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Carpenter S, Groschup MH, Garros C, Felippe-Bauer ML, Purse BV. Culicoides biting midges, arboviruses and public health in Europe. Antiviral Res 2013; 100:102-13. [PMID: 23933421 DOI: 10.1016/j.antiviral.2013.07.020] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 07/22/2013] [Accepted: 07/30/2013] [Indexed: 11/25/2022]
Abstract
The emergence of multiple strains of bluetongue virus (BTV) and the recent discovery of Schmallenberg virus (SBV) in Europe have highlighted the fact that exotic Culicoides-borne arboviruses from remote geographic areas can enter and spread rapidly in this region. This review considers the potential for this phenomenon to impact on human health in Europe, by examining evidence of the role of Culicoides biting midges in the zoonotic transmission and person-to-person spread of arboviruses worldwide. To date, the only arbovirus identified as being primarily transmitted by Culicoides to and between humans is Oropouche virus (OROV). This member of the genus Orthobunyavirus causes major epidemics of febrile illness in human populations of South and Central America and the Caribbean. We examine factors promoting sustained outbreaks of OROV in Brazil from an entomological perspective and assess aspects of the epidemiology of this arbovirus that are currently poorly understood, but may influence the risk of incursion into Europe. We then review the secondary and rarely reported role of Culicoides in the transmission of high-profile zoonotic infections, while critically reviewing evidence of this phenomenon in endemic transmission and place this in context with the presence of other potential vector groups in Europe. Scenarios for the incursions of Culicoides-borne human-to-human transmitted and zoonotic arboviruses are then discussed, along with control measures that could be employed to reduce their impact. These measures are placed in the context of legislative measures used during current and ongoing outbreaks of Culicoides-borne arboviruses in Europe, involving both veterinary and public health sectors.
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Affiliation(s)
- Simon Carpenter
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK.
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Veronesi E, Antony F, Gubbins S, Golding N, Blackwell A, Mertens PPC, Brownlie J, Darpel KE, Mellor PS, Carpenter S. Measurement of the infection and dissemination of bluetongue virus in culicoides biting midges using a semi-quantitative rt-PCR assay and isolation of infectious virus. PLoS One 2013; 8:e70800. [PMID: 23940643 PMCID: PMC3733650 DOI: 10.1371/journal.pone.0070800] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 06/24/2013] [Indexed: 11/20/2022] Open
Abstract
Background Culicoides biting midges (Diptera: Ceratopogonidae) are the biological vectors of globally significant arboviruses of livestock including bluetongue virus (BTV), African horse sickness virus (AHSV) and the recently emerging Schmallenberg virus (SBV). From 2006–2009 outbreaks of BTV in northern Europe inflicted major disruption and economic losses to farmers and several attempts were made to implicate Palaearctic Culicoides species as vectors. Results from these studies were difficult to interpret as they used semi-quantitative RT-PCR (sqPCR) assays as the major diagnostic tool, a technique that had not been validated for use in this role. In this study we validate the use of these assays by carrying out time-series detection of BTV RNA in two colony species of Culicoides and compare the results with the more traditional isolation of infectious BTV on cell culture. Methodology/Principal Findings A BTV serotype 1 strain mixed with horse blood was fed to several hundred individuals of Culicoides sonorensis (Wirth & Jones) and C. nubeculosus (Mg.) using a membrane-based assay and replete individuals were then incubated at 25°C. At daily intervals 25 Culicoides of each species were removed from incubation, homogenised and BTV quantified in each individual using sqPCR (Cq values) and virus isolation on a KC-C. sonorensis embryonic cell line, followed by antigen enzyme-linked immunosorbent assay (ELISA). In addition, comparisons were also drawn between the results obtained with whole C. sonorensis and with individually dissected individuals to determine the level of BTV dissemination. Conclusions/Significance Cq values generated from time-series infection experiments in both C. sonorensis and C. nubeculosus confirmed previous studies that relied upon the isolation and detection of infectious BTV. Implications on the testing of field-collected Culicoides as potential virus vectors by PCR assays and the use of such assays as front-line tools for use in diagnostic laboratories in this role are discussed.
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Affiliation(s)
- Eva Veronesi
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | - Frank Antony
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | - Simon Gubbins
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | - Nick Golding
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | | | - Peter PC. Mertens
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | - Joe Brownlie
- Royal Veterinary College, Hatfield, Herts, United Kingdom
| | - Karin E. Darpel
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Surrey, United Kingdom
- University of Surrey, Guildford, Surrey, United Kingdom
| | - Philip S. Mellor
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | - Simon Carpenter
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Pirbright, Surrey, United Kingdom
- * E-mail:
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Charron MVP, Kluiters G, Langlais M, Seegers H, Baylis M, Ezanno P. Seasonal and spatial heterogeneities in host and vector abundances impact the spatiotemporal spread of bluetongue. Vet Res 2013; 44:44. [PMID: 23782421 PMCID: PMC3701505 DOI: 10.1186/1297-9716-44-44] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 06/07/2013] [Indexed: 11/10/2022] Open
Abstract
Bluetongue (BT) can cause severe livestock losses and large direct and indirect costs for farmers. To propose targeted control strategies as alternative to massive vaccination, there is a need to better understand how BT virus spread in space and time according to local characteristics of host and vector populations. Our objective was to assess, using a modelling approach, how spatiotemporal heterogeneities in abundance and distribution of hosts and vectors impact the occurrence and amplitude of local and regional BT epidemics. We built a reaction-diffusion model accounting for the seasonality in vector abundance and the active dispersal of vectors. Because of the scale chosen, and movement restrictions imposed during epidemics, host movements and wind-induced passive vector movements were neglected. Four levels of complexity were addressed using a theoretical approach, from a homogeneous to a heterogeneous environment in abundance and distribution of hosts and vectors. These scenarios were illustrated using data on abundance and distribution of hosts and vectors in a real geographical area. We have shown that local epidemics can occur earlier and be larger in scale far from the primary case rather than close to it. Moreover, spatial heterogeneities in hosts and vectors delay the epidemic peak and decrease the infection prevalence. The results obtained on a real area confirmed those obtained on a theoretical domain. Although developed to represent BTV spatiotemporal spread, our model can be used to study other vector-borne diseases of animals with a local to regional spread by vector diffusion.
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Affiliation(s)
- Maud V P Charron
- INRA, UMR1300 Biologie, Epidémiologie et Analyse de Risques en santé animale, CS 40706, F-44307 Nantes, France.
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Kirkeby C, Græsbøll K, Stockmarr A, Christiansen LE, Bødker R. The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae). Parasit Vectors 2013; 6:67. [PMID: 23497628 PMCID: PMC3617071 DOI: 10.1186/1756-3305-6-67] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 02/20/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light traps. METHODS Here we test a previously described mathematical model (Model I) and two novel models for the attraction of vectors to light traps (Model II and III). In Model I, Culicoides fly to the nearest trap from within a fixed range of attraction. In Model II Culicoides fly towards areas with greater light intensity, and in Model III Culicoides evaluate light sources in the field of view and fly towards the strongest. Model II and III incorporated the directionally dependent light field created around light traps with fluorescent light tubes. All three models were fitted to light trap collections obtained from two novel experimental setups in the field where traps were placed in different configurations. RESULTS Results showed that overlapping ranges of attraction of neighboring traps extended the shared range of attraction. Model I did not fit data from any of the experimental setups. Model II could only fit data from one of the setups, while Model III fitted data from both experimental setups. CONCLUSIONS The model with the best fit, Model III, indicates that Culicoides continuously evaluate the light source direction and intensity. The maximum range of attraction of a single 4W CDC light trap was estimated to be approximately 15.25 meters. The attraction towards light traps is different from the attraction to host animals and thus light trap catches may not represent the vector species and numbers attracted to hosts.
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Affiliation(s)
- Carsten Kirkeby
- National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, Frederiksberg C, DK-1870, Denmark.
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Rigot T, Drubbel MV, Delécolle JC, Gilbert M. Farms, pastures and woodlands: the fine-scale distribution of Palearctic Culicoides spp. biting midges along an agro-ecological gradient. MEDICAL AND VETERINARY ENTOMOLOGY 2013; 27:29-38. [PMID: 22897885 DOI: 10.1111/j.1365-2915.2012.01032.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The spatial epidemiology of Bluetongue virus (BTV) at the landscape level relates to the fine-scale distribution and dispersal capacities of its vectors, midges belonging to the genus Culicoides Latreille (Diptera: Ceratopogonidae). Although many previous researches have carried out Culicoides sampling on farms, little is known of the fine-scale distribution of Culicoides in the landscape immediately surrounding farms. The aim of this study was to gain a better understanding of Culicoides populations at increasing distances from typical dairy farms in north-west Europe, through the use of eight Onderstepoort-type black-light traps positioned along linear transects departing from farms, going through pastures and entering woodlands. A total of 16 902 Culicoides were collected in autumn 2008 and spring 2009. The majority were females, of which more than 97% were recognized as potential vectors. In pastures, we found decreasing numbers of female Culicoides as a function of the distance to the farm. This pattern was modelled by leptokurtic models, with parameters depending on season and species. By contrast, the low number of male Culicoides caught were homogeneously distributed along the transects. When transects entered woodlands, we found a higher abundance of Culicoides than expected considering the distance of the sampling sites to the farm, although this varied according to species.
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Affiliation(s)
- T Rigot
- Lutte Biologique et Ecologie Spatiale (LUBIES), Université Libre de Bruxelles, Brussels, Belgium.
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Kirkeby C, Bødker R, Stockmarr A, Lind P. Spatial abundance and clustering of Culicoides (Diptera: Ceratopogonidae) on a local scale. Parasit Vectors 2013; 6:43. [PMID: 23433251 PMCID: PMC3608001 DOI: 10.1186/1756-3305-6-43] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 01/24/2013] [Indexed: 11/21/2022] Open
Abstract
Background Biting midges, Culicoides, of the Obsoletus group and the Pulicaris group have been involved in recent outbreaks of bluetongue virus and the former was also involved in the Schmallenberg virus outbreak in northern Europe. Methods For the first time, here we investigate the local abundance pattern of these two species groups in the field by intensive sampling with a grid of light traps on 16 catch nights. Neighboring trap catches can be spatially dependent on each other, hence we developed a conditional autoregressive (CAR) model framework to test a number of spatial and non-spatial covariates expected to affect Culicoides abundance. Results The distance to sheep penned in the corner of the study field significantly increased the abundance level up to 200 meters away from the sheep. Spatial clustering was found to be significant but could not be explained by any known factors, and cluster locations shifted between catch nights. No significant temporal autocorrelation was detected. CAR models for both species groups identified a significant positive impact of humidity and significant negative impacts of precipitation and wind turbulence. Temperature was also found to be significant with a peak at just below 16 degrees Celcius. Surprisingly, there was a significant positive impact of wind speed. The CAR model for the Pulicaris group also identified a significant attraction to the smaller groups of sheep placed in the field. Furthermore, a large number of spatial covariates which were incorrectly found to be significant in ordinary regression models were not significant in the CAR models. The 95% C.I. on the prediction estimates ranged from 20.4% to 304.8%, underlining the difficulties of predicting the abundance of Culicoides. Conclusions We found that significant spatial clusters of Culicoides moved around in a dynamic pattern varying between catch nights. This conforms with the modeling but was not explained by any of the tested covariates. The mean abundance within these clusters was up to 11 times higher for the Obsoletus group and 4 times higher for the Pulicaris group compared to the rest of the field.
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Affiliation(s)
- Carsten Kirkeby
- National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, Frederiksberg C, DK-1870, Denmark.
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Bessell PR, Searle KR, Auty HK, Handel IG, Purse BV, Bronsvoort BMD. Epidemic potential of an emerging vector borne disease in a marginal environment: Schmallenberg in Scotland. Sci Rep 2013; 3:1178. [PMID: 23378911 PMCID: PMC3560360 DOI: 10.1038/srep01178] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 01/11/2013] [Indexed: 12/22/2022] Open
Abstract
During 2011 Schmallenberg virus (SBV) presented as a novel disease of cattle and sheep that had apparently spread through northern Europe over a relatively short period of time, but has yet to infect Scotland. This paper describes the development of a model of SBV spread applied to Scotland in the event of an incursion. This model shows that SBV spread is very sensitive to the temperature, with relatively little spread and few reproductive losses predicted in years with average temperatures but extensive spread (>1 million animals infected) and substantial reproductive losses in the hottest years. These results indicate that it is possible for SBV to spread in Scotland, however spread is limited by climatic conditions and the timing of introduction. Further results show that the transmission kernel shape and extrinsic incubation period parameter have a non-linear effect on disease transmission, so a greater understanding of the SBV transmission parameters is required.
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Affiliation(s)
- Paul R Bessell
- The Roslin Institute, The University of Edinburgh, Easter Bush, EH25 9RG.
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Abstract
Arboviruses are transmitted to vertebrate hosts by biting arthropod vectors such as mosquitoes, ticks, and midges. These viruses replicate in both arthropods and vertebrates and are thus exposed to different antiviral responses in these organisms. RNA interference (RNAi) is a sequence-specific RNA degradation mechanism that has been shown to play a major role in the antiviral response against arboviruses in mosquitoes. Culicoides midges are important vectors of arboviruses, known to transmit pathogens of humans and livestock such as bluetongue virus (BTV) (Reoviridae), Oropouche virus (Bunyaviridae), and likely the recently discovered Schmallenberg virus (Bunyaviridae). In this study, we investigated whether Culicoides cells possess an antiviral RNAi response and whether this is effective against arboviruses, including those with double-stranded RNA (dsRNA) genomes, such as BTV. Using reporter gene-based assays, we established the presence of a functional RNAi response in Culicoides sonorensis-derived KC cells which is effective in inhibiting BTV infection. Sequencing of small RNAs from KC and Aedes aegypti-derived Aag2 cells infected with BTV or the unrelated Schmallenberg virus resulted in the production of virus-derived small interfering RNAs (viRNAs) of 21 nucleotides, similar to the viRNAs produced during arbovirus infections of mosquitoes. In addition, viRNA profiles strongly suggest that the BTV dsRNA genome is accessible to a Dicer-type nuclease. Thus, we show for the first time that midge cells target arbovirus replication by mounting an antiviral RNAi response mainly resembling that of other insect vectors of arboviruses.
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