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Zhang X, Li J, Gerry AC. Seasonal change and influence of environmental variables on host-seeking activity of the biting midge Culicoides sonorensis at a southern California dairy, USA. Parasit Vectors 2024; 17:212. [PMID: 38730488 PMCID: PMC11083819 DOI: 10.1186/s13071-024-06290-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 04/19/2024] [Indexed: 05/13/2024] Open
Abstract
BACKGROUND As a primary vector of bluetongue virus (BTV) in the US, seasonal abundance and diel flight activity of Culicoides sonorensis has been documented, but few studies have examined how time of host-seeking activity is impacted by environmental factors. This knowledge is essential for interpreting surveillance data and modeling pathogen transmission risk. METHODS The diel host-seeking activity of C. sonorensis was studied on a California dairy over 3 years using a time-segregated trap baited with CO2. The relationship between environmental variables and diel host-seeking activity (start, peak, and duration of activity) of C. sonorensis was evaluated using multiple linear regression. Fisher's exact test and paired-sample z-test were used to evaluate the seasonal difference and parity difference on diel host-seeking activity. RESULTS Host-seeking by C. sonorensis began and reached an activity peak before sunset at a higher frequency during colder months relative to warmer months. The time that host-seeking activity occurred was associated low and high daily temperature as well as wind speed at sunset. Colder temperatures and a greater diurnal temperature range were associated with an earlier peak in host-seeking. Higher wind speeds at sunset were associated with a delayed peak in host-seeking and a shortened duration of host-seeking. Parous midges reached peak host-seeking activity slightly later than nulliparous midges, possibly because of the need for oviposition by gravid females before returning to host-seeking. CONCLUSIONS This study demonstrates that during colder months C. sonorensis initiates host-seeking and reaches peak host-seeking activity earlier relative to sunset, often even before sunset, compared to warmer months. Therefore, the commonly used UV light-baited traps are ineffective for midge surveillance before sunset. Based on this study, surveillance methods that do not rely on light trapping would provide a more accurate estimate of host-biting risk across seasons. The association of environmental factors to host-seeking shown in this study can be used to improve modeling or prediction of host-seeking activity. This study identified diurnal temperature range as associated with host-seeking activity, suggesting that Culicoides may respond to a rapidly decreasing temperature by shifting to an earlier host-seeking time, though this association needs further study.
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Affiliation(s)
- Xinmi Zhang
- Department of Entomology, University of California Riverside, Riverside, CA, USA.
| | - Jun Li
- Department of Statistics, University of California Riverside, Riverside, CA, USA
| | - Alec C Gerry
- Department of Entomology, University of California Riverside, Riverside, CA, USA.
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Boender GJ, Hagenaars TJ, Holwerda M, Spierenburg MAH, van Rijn PA, van der Spek AN, Elbers ARW. Spatial Transmission Characteristics of the Bluetongue Virus Serotype 3 Epidemic in The Netherlands, 2023. Viruses 2024; 16:625. [PMID: 38675966 PMCID: PMC11054275 DOI: 10.3390/v16040625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/12/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
A devastating bluetongue (BT) epidemic caused by bluetongue virus serotype 3 (BTV-3) has spread throughout most of the Netherlands within two months since the first infection was officially confirmed in the beginning of September 2023. The epidemic comes with unusually strong suffering of infected cattle through severe lameness, often resulting in mortality or euthanisation for welfare reasons. In total, tens of thousands of sheep have died or had to be euthanised. By October 2023, more than 2200 locations with ruminant livestock were officially identified to be infected with BTV-3, and additionally, ruminants from 1300 locations were showing BTV-associated clinical symptoms (but not laboratory-confirmed BT). Here, we report on the spatial spread and dynamics of this BT epidemic. More specifically, we characterized the distance-dependent intensity of the between-holding transmission by estimating the spatial transmission kernel and by comparing it to transmission kernels estimated earlier for BTV-8 transmission in Northwestern Europe in 2006 and 2007. The 2023 BTV-3 kernel parameters are in line with those of the transmission kernel estimated previously for the between-holding spread of BTV-8 in Europe in 2007. The 2023 BTV-3 transmission kernel has a long-distance spatial range (across tens of kilometres), evidencing that in addition to short-distance dispersal of infected midges, other transmission routes such as livestock transports probably played an important role.
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Affiliation(s)
- Gert-Jan Boender
- Department of Epidemiology, Bioinformatics, Animal Studies and Vaccine Development, Wageningen Bioveterinary Research, P.O. Box 65, 8200 AB Lelystad, The Netherlands; (G.-J.B.); (T.J.H.)
| | - Thomas J. Hagenaars
- Department of Epidemiology, Bioinformatics, Animal Studies and Vaccine Development, Wageningen Bioveterinary Research, P.O. Box 65, 8200 AB Lelystad, The Netherlands; (G.-J.B.); (T.J.H.)
| | - Melle Holwerda
- Department of Virology, Wageningen Bioveterinary Research, P.O. Box 65, 8200 AB Lelystad, The Netherlands; (M.H.); (P.A.v.R.)
| | - Marcel A. H. Spierenburg
- Incident- and Crisis Centre (NVIC), Netherlands Food and Consumer Product Safety Authority (NVWA), P.O. Box 43006, 3540 AA Utrecht, The Netherlands; (M.A.H.S.); (A.N.v.d.S.)
| | - Piet A. van Rijn
- Department of Virology, Wageningen Bioveterinary Research, P.O. Box 65, 8200 AB Lelystad, The Netherlands; (M.H.); (P.A.v.R.)
- Department of Biochemistry, Centre for Human Metabolomics, North-West University, Private Bag X 6001, Potchefstroom 2520, South Africa
| | - Arco N. van der Spek
- Incident- and Crisis Centre (NVIC), Netherlands Food and Consumer Product Safety Authority (NVWA), P.O. Box 43006, 3540 AA Utrecht, The Netherlands; (M.A.H.S.); (A.N.v.d.S.)
| | - Armin R. W. Elbers
- Department of Epidemiology, Bioinformatics, Animal Studies and Vaccine Development, Wageningen Bioveterinary Research, P.O. Box 65, 8200 AB Lelystad, The Netherlands; (G.-J.B.); (T.J.H.)
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Erram D, Burkett-Cadena N. Oviposition of Culicoides insignis (Diptera: Ceratopogonidae) under laboratory conditions with notes on the developmental life history traits of its immature stages. Parasit Vectors 2021; 14:522. [PMID: 34627349 PMCID: PMC8501582 DOI: 10.1186/s13071-021-05025-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 09/16/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Culicoides insignis is a confirmed vector of bluetongue virus (BTV) throughout the American tropics and a possible vector of epizootic hemorrhagic disease virus (EHDV) in Florida. Despite its importance, fundamental information on the biology and ecology of this vector species is lacking. In this study, we examined the oviposition of C. insignis under laboratory conditions, monitored the development of immature stages and attempted colonization of this species. METHODS Live C. insignis females were collected from the field using CDC-UV-LED traps, allowed to blood-feed on live chicken and given various natural substrates for oviposition in two-choice assays. The eggs deposited were transferred to 0.3% agar slants, and the hatched larvae were provided a diet of Panagrellus redivivus Linnaeus nematodes and the development of all immature stages was monitored. RESULTS Culicoides insignis females exhibited an overall oviposition preference for dishes containing mud from their larval habitat as gravid females deposited a significantly higher number of eggs on these dishes (35.3 eggs/female) than on controls (17.7 eggs/female). The ovipositing females also deposited a higher percentage of eggs on substrates with habitat mud and other organically enriched muds (≥ 75.2%) compared to controls (31.0%). The larvae developed successfully to adulthood on the nematode diet, exhibiting high overall larval survival rates (85.0%). Sex ratios of the F1 generation were male biased, approximately 3:1 (male:female). Captive mating could not be induced in the F1 adults. CONCLUSIONS Mud from the larval habitat and other organically enriched muds provide strong oviposition cues to C. insignis under laboratory conditions. Further studies will be needed to identify the key biotic/abiotic factors influencing midge oviposition in the field. The agar/nematode method is effective for the rearing of C. insignis larvae. However, further studies will be needed to address the issue of male-biased sex ratios in the progeny and to examine the mating habits/cues of C. insignis in nature, which may provide clues towards inducing captive mating in the F1 adults.
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Affiliation(s)
- Dinesh Erram
- Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, 200 9th St. SE, Vero Beach, FL, 32962, USA.
| | - Nathan Burkett-Cadena
- Florida Medical Entomology Laboratory, Institute of Food and Agricultural Sciences, University of Florida, 200 9th St. SE, Vero Beach, FL, 32962, USA
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Barceló C, Miranda MA. Development and lifespan of Culicoides obsoletus s.s. (Meigen) and other livestock-associated species reared at different temperatures under laboratory conditions. Med Vet Entomol 2021; 35:187-201. [PMID: 33103805 DOI: 10.1111/mve.12487] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 09/21/2020] [Accepted: 10/11/2020] [Indexed: 06/11/2023]
Abstract
Culicoides Latreille (Diptera: Ceratopogonidae) transmit arboviruses affecting wild and domestic ruminants such as bluetongue (BTV) and Schmallenberg virus (SBV). The sub-adult development and lifespan of Culicoides obsoletus s.s. (Meigen), Culicoides circumscriptus Kieffer and Culicoides paolae Boorman were examined at three different temperatures under laboratory conditions. Insects were collected from field between spring and autumn 2015 in two livestock farms located in Majorca (Spain). Gravid females were held individually at 18, 25 or 30 °C. Low temperatures increased the adult lifespan, time to oviposit and rate of development, whereas high temperatures increased the number of eggs, successful pupation and adult emergence as well as the larvae growth rate. The results showed that C. obsoletus s.s. have optimum development at 18 °C, whereas the optimal rearing temperature for C. circumscriptus and C. paolae was under warmer conditions of 25-30 °C. Variations in temperature/humidity and assays with different materials and substrates for oviposition should be considered in future studies. Understanding the requirements of the different species of Culicoides optimizing the results should be of special interest for predicting environmental change effects on these species, in addition to determining the rearing conditions for candidate Culicoides vectors.
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Affiliation(s)
- C Barceló
- Applied Zoology and Animal Conservation Group, Department of Biology, University of the Balearic Islands (UIB), Palma de Mallorca, Spain
| | - M A Miranda
- Applied Zoology and Animal Conservation Group, Department of Biology, University of the Balearic Islands (UIB), Palma de Mallorca, Spain
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Grimaud Y, Tran A, Benkimoun S, Boucher F, Esnault O, Cêtre-Sossah C, Cardinale E, Garros C, Guis H. Spatio-temporal modelling of Culicoides Latreille (Diptera: Ceratopogonidae) populations on Reunion Island (Indian Ocean). Parasit Vectors 2021; 14:288. [PMID: 34044880 PMCID: PMC8161615 DOI: 10.1186/s13071-021-04780-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 05/11/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Reunion Island regularly faces outbreaks of bluetongue and epizootic hemorrhagic diseases, two insect-borne orbiviral diseases of ruminants. Hematophagous midges of the genus Culicoides (Diptera: Ceratopogonidae) are the vectors of bluetongue (BTV) and epizootic hemorrhagic disease (EHDV) viruses. In a previous study, statistical models based on environmental and meteorological data were developed for the five Culicoides species present in the island to provide a better understanding of their ecology and predict their presence and abundance. The purpose of this study was to couple these statistical models with a Geographic Information System (GIS) to produce dynamic maps of the distribution of Culicoides throughout the island. METHODS Based on meteorological data from ground weather stations and satellite-derived environmental data, the abundance of each of the five Culicoides species was estimated for the 2214 husbandry locations on the island for the period ranging from February 2016 to June 2018. A large-scale Culicoides sampling campaign including 100 farms was carried out in March 2018 to validate the model. RESULTS According to the model predictions, no husbandry location was free of Culicoides throughout the study period. The five Culicoides species were present on average in 57.0% of the husbandry locations for C. bolitinos Meiswinkel, 40.7% for C. enderleini Cornet & Brunhes, 26.5% for C. grahamii Austen, 87.1% for C. imicola Kieffer and 91.8% for C. kibatiensis Goetghebuer. The models also showed high seasonal variations in their distribution. During the validation process, predictions were acceptable for C. bolitinos, C. enderleini and C. kibatiensis, with normalized root mean square errors (NRMSE) of 15.4%, 13.6% and 16.5%, respectively. The NRMSE was 27.4% for C. grahamii. For C. imicola, the NRMSE was acceptable (11.9%) considering all husbandry locations except in two specific areas, the Cirque de Salazie-an inner mountainous part of the island-and the sea edge, where the model overestimated its abundance. CONCLUSIONS Our model provides, for the first time to our knowledge, an operational tool to better understand and predict the distribution of Culicoides in Reunion Island. As it predicts a wide spatial distribution of the five Culicoides species throughout the year and taking into consideration their vector competence, our results suggest that BTV and EHDV can circulate continuously on the island. As further actions, our model could be coupled with an epidemiological model of BTV and EHDV transmission to improve risk assessment of Culicoides-borne diseases on the island.
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Affiliation(s)
- Yannick Grimaud
- GDS Réunion, 1 rue du Père Hauck, 97418 La Plaine des Cafres, La Réunion, France
- University of Reunion Island, 15 avenue René Cassin, Sainte-Clotilde, 97715 La Réunion, France
- CIRAD, UMR ASTRE, Sainte-Clotilde, 97490 La Réunion, France
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
| | - Annelise Tran
- CIRAD, UMR ASTRE, Sainte-Clotilde, 97490 La Réunion, France
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
- CIRAD, UMR TETIS, Sainte-Clotilde, 97490 La Réunion, France
- TETIS, University of Montpellier, AgroParisTech, CIRAD, CNRS, INRAE, Montpellier, France
| | - Samuel Benkimoun
- CIRAD, UMR ASTRE, Sainte-Clotilde, 97490 La Réunion, France
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
- CIRAD, UMR TETIS, Sainte-Clotilde, 97490 La Réunion, France
- TETIS, University of Montpellier, AgroParisTech, CIRAD, CNRS, INRAE, Montpellier, France
| | - Floriane Boucher
- CIRAD, UMR ASTRE, Sainte-Clotilde, 97490 La Réunion, France
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
| | - Olivier Esnault
- GDS Réunion, 1 rue du Père Hauck, 97418 La Plaine des Cafres, La Réunion, France
| | - Catherine Cêtre-Sossah
- CIRAD, UMR ASTRE, Sainte-Clotilde, 97490 La Réunion, France
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
| | - Eric Cardinale
- CIRAD, UMR ASTRE, Sainte-Clotilde, 97490 La Réunion, France
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
| | - Claire Garros
- CIRAD, UMR ASTRE, Sainte-Clotilde, 97490 La Réunion, France
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
| | - Hélène Guis
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
- CIRAD, UMR ASTRE, 101 Antananarivo, Madagascar
- Institut Pasteur of Madagascar, Epidemiology and Clinical Research Unit, Antananarivo, Madagascar
- FOFIFA DRZVP, Antananarivo, Madagascar
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De Clercq K, Vandaele L, Vanbinst T, Riou M, Deblauwe I, Wesselingh W, Pinard A, Van Eetvelde M, Boulesteix O, Leemans B, Gélineau R, Vercauteren G, Van der Heyden S, Beckers JF, Saegerman C, Sammin D, de Kruif A, De Leeuw I. Transmission of Bluetongue Virus Serotype 8 by Artificial Insemination with Frozen-Thawed Semen from Naturally Infected Bulls. Viruses 2021; 13:v13040652. [PMID: 33918924 PMCID: PMC8069090 DOI: 10.3390/v13040652] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/31/2021] [Accepted: 04/07/2021] [Indexed: 12/31/2022] Open
Abstract
Transmission of bluetongue (BT) virus serotype 8 (BTV-8) via artificial insemination of contaminated frozen semen from naturally infected bulls was investigated in two independent experiments. Healthy, BT negative heifers were hormonally synchronized and artificially inseminated at oestrus. In total, six groups of three heifers received semen from four batches derived from three bulls naturally infected with BTV-8. Each experiment included one control heifer that was not inseminated and that remained BT negative throughout. BTV viraemia and seroconversion were determined in 8 out of 18 inseminated heifers, and BTV was isolated from five of these animals. These eight heifers only displayed mild clinical signs of BT, if any at all, but six of them experienced pregnancy loss between weeks four and eight of gestation, and five of them became BT PCR and antibody positive. The other two infected heifers gave birth at term to two healthy and BT negative calves. The BT viral load varied among the semen batches used and this had a significant impact on the infection rate, the time of onset of viraemia post artificial insemination, and the gestational stage at which pregnancy loss occurred. These results, which confirm unusual features of BTV-8 infection, should not be extrapolated to infection with other BTV strains without thorough evaluation. This study also adds weight to the hypothesis that the re-emergence of BTV-8 in France in 2015 may be attributable to the use of contaminated bovine semen.
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Affiliation(s)
- Kris De Clercq
- Unit of Exotic and Particular Diseases, Scientific Directorate Infectious Diseases in Animals, Sciensano, 1180 Brussels, Belgium; (I.D.L.)
- Correspondence:
| | - Leen Vandaele
- Department of Reproduction, Obstetrics and Herd Health, Ghent University, 9820 Merelbeke, Belgium; (L.V.); (W.W.); (M.V.E.); (B.L.); (A.d.K.)
| | - Tine Vanbinst
- Unit of Exotic and Particular Diseases, Scientific Directorate Infectious Diseases in Animals, Sciensano, 1180 Brussels, Belgium; (I.D.L.)
| | - Mickaël Riou
- UE-1277 Plateforme d’Infectiologie Expérimentale (PFIE), Centre de Recherche Val de Loire, Institut National de Recherche Pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), 37380 Nouzilly, France; (M.R.); (A.P.); (O.B.); (R.G.)
| | - Isra Deblauwe
- The Unit of Entomology, Department of Biomedical Sciences, Institute of Tropical Medicine, 2000 Antwerp, Belgium;
| | - Wendy Wesselingh
- Department of Reproduction, Obstetrics and Herd Health, Ghent University, 9820 Merelbeke, Belgium; (L.V.); (W.W.); (M.V.E.); (B.L.); (A.d.K.)
| | - Anne Pinard
- UE-1277 Plateforme d’Infectiologie Expérimentale (PFIE), Centre de Recherche Val de Loire, Institut National de Recherche Pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), 37380 Nouzilly, France; (M.R.); (A.P.); (O.B.); (R.G.)
| | - Mieke Van Eetvelde
- Department of Reproduction, Obstetrics and Herd Health, Ghent University, 9820 Merelbeke, Belgium; (L.V.); (W.W.); (M.V.E.); (B.L.); (A.d.K.)
| | - Olivier Boulesteix
- UE-1277 Plateforme d’Infectiologie Expérimentale (PFIE), Centre de Recherche Val de Loire, Institut National de Recherche Pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), 37380 Nouzilly, France; (M.R.); (A.P.); (O.B.); (R.G.)
| | - Bart Leemans
- Department of Reproduction, Obstetrics and Herd Health, Ghent University, 9820 Merelbeke, Belgium; (L.V.); (W.W.); (M.V.E.); (B.L.); (A.d.K.)
| | - Robert Gélineau
- UE-1277 Plateforme d’Infectiologie Expérimentale (PFIE), Centre de Recherche Val de Loire, Institut National de Recherche Pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), 37380 Nouzilly, France; (M.R.); (A.P.); (O.B.); (R.G.)
| | - Griet Vercauteren
- Department of Pathology, Bacteriology and Poultry Diseases, 9820 Merelbeke, Belgium; (G.V.); (S.V.d.H.)
| | - Sara Van der Heyden
- Department of Pathology, Bacteriology and Poultry Diseases, 9820 Merelbeke, Belgium; (G.V.); (S.V.d.H.)
| | - Jean-François Beckers
- Département des Sciences Fonctionnelles (DSF), Faculty of Veterinary Medicine, University of Liège, Quartier Vallée 2, 4000 Liège, Belgium;
| | - Claude Saegerman
- Research Unit in Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULg), Fundamental and Applied Research for Animal and Health (FARAH) Center, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, 4130 Liege, Belgium;
| | - Donal Sammin
- Department of Agriculture Food and the Marine Laboratories, Backweston, W23 X3PH Co. Kildare, Ireland;
| | - Aart de Kruif
- Department of Reproduction, Obstetrics and Herd Health, Ghent University, 9820 Merelbeke, Belgium; (L.V.); (W.W.); (M.V.E.); (B.L.); (A.d.K.)
| | - Ilse De Leeuw
- Unit of Exotic and Particular Diseases, Scientific Directorate Infectious Diseases in Animals, Sciensano, 1180 Brussels, Belgium; (I.D.L.)
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Mignotte A, Garros C, Dellicour S, Jacquot M, Gilbert M, Gardès L, Balenghien T, Duhayon M, Rakotoarivony I, de Wavrechin M, Huber K. High dispersal capacity of Culicoides obsoletus (Diptera: Ceratopogonidae), vector of bluetongue and Schmallenberg viruses, revealed by landscape genetic analyses. Parasit Vectors 2021; 14:93. [PMID: 33536057 PMCID: PMC7860033 DOI: 10.1186/s13071-020-04522-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 12/04/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND In the last two decades, recurrent epizootics of bluetongue virus and Schmallenberg virus have been reported in the western Palearctic region. These viruses affect domestic cattle, sheep, goats and wild ruminants and are transmitted by native hematophagous midges of the genus Culicoides (Diptera: Ceratopogonidae). Culicoides dispersal is known to be stratified, i.e. due to a combination of dispersal processes occurring actively at short distances and passively or semi-actively at long distances, allowing individuals to jump hundreds of kilometers. METHODS Here, we aim to identify the environmental factors that promote or limit gene flow of Culicoides obsoletus, an abundant and widespread vector species in Europe, using an innovative framework integrating spatial, population genetics and statistical approaches. A total of 348 individuals were sampled in 46 sites in France and were genotyped using 13 newly designed microsatellite markers. RESULTS We found low genetic differentiation and a weak population structure for C. obsoletus across the country. Using three complementary inter-individual genetic distances, we did not detect any significant isolation by distance, but did detect significant anisotropic isolation by distance on a north-south axis. We employed a multiple regression on distance matrices approach to investigate the correlation between genetic and environmental distances. Among all the environmental factors that were tested, only cattle density seems to have an impact on C. obsoletus gene flow. CONCLUSIONS The high dispersal capacity of C. obsoletus over land found in the present study calls for a re-evaluation of the impact of Culicoides on virus dispersal, and highlights the urgent need to better integrate molecular, spatial and statistical information to guide vector-borne disease control.
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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
| | - Simon Dellicour
- Spatial Epidemiology Lab (SpELL), Université Libre de Bruxelles, CP160/12, 50, av. FD Roosevelt, 1050 Bruxelles, Belgium
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Maude Jacquot
- Spatial Epidemiology Lab (SpELL), Université Libre de Bruxelles, CP160/12, 50, av. FD Roosevelt, 1050 Bruxelles, Belgium
- UMR EPIA, Université Clermont Auvergne, INRAE, VetAgro Sup, 63122 Saint-Genès-Champanelle, France
| | - Marius Gilbert
- Spatial Epidemiology Lab (SpELL), Université Libre de Bruxelles, CP160/12, 50, av. FD Roosevelt, 1050 Bruxelles, Belgium
| | - 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, 10100 Rabat, Morocco
- Unité Microbiologie, immunologie et maladies contagieuses, Institut Agronomique et Vétérinaire Hassan II, 10100 Rabat-Instituts, 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
| | - Maïa de Wavrechin
- ASTRE, Univ Montpellier, Cirad, INRAE, Montpellier, France
- Cirad, UMR ASTRE, 34398 Montpellier, France
| | - Karine Huber
- ASTRE, Univ Montpellier, Cirad, INRAE, Montpellier, France
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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. J Med Entomol 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Aguilar-Vega C, Bosch J, Fernández-Carrión E, Lucientes J, Sánchez-Vizcaíno JM. Identifying Spanish Areas at More Risk of Monthly BTV Transmission with a Basic Reproduction Number Approach. Viruses 2020; 12:E1158. [PMID: 33066209 PMCID: PMC7602074 DOI: 10.3390/v12101158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/08/2020] [Accepted: 10/12/2020] [Indexed: 01/24/2023] Open
Abstract
Bluetongue virus (BTV) causes a disease that is endemic in Spain and its two major biological vector species, C. imicola and the Obsoletus complex species, differ greatly in their ecology and distribution. Understanding the seasonality of BTV transmission in risk areas is key to improving surveillance and control programs, as well as to better understand the pathogen transmission networks between wildlife and livestock. Here, monthly risk transmission maps were generated using risk categories based on well-known BTV R0 equations and predicted abundances of the two most relevant vectors in Spain. Previously, Culicoides spp. predicted abundances in mainland Spain and the Balearic Islands were obtained using remote sensing data and random forest machine learning algorithm. Risk transmission maps were externally assessed with the estimated date of infection of BTV-1 and BTV-4 historical outbreaks. Our results highlight the differences in risk transmission during April-October, June-August being the period with higher R0 values. Likewise, a natural barrier has been identified between northern and central-southern areas at risk that may hamper BTV spread between them. Our results can be relevant to implement risk-based interventions for the prevention, control and surveillance of BTV and other diseases shared between livestock and wildlife host populations.
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Affiliation(s)
- Cecilia Aguilar-Vega
- VISAVET Health Surveillance Centre, Animal Health Department, Faculty of Veterinary Medicine, Complutense University of Madrid, 28040 Madrid, Spain; (J.B.); (E.F.-C.); (J.M.S.-V.)
| | - Jaime Bosch
- VISAVET Health Surveillance Centre, Animal Health Department, Faculty of Veterinary Medicine, Complutense University of Madrid, 28040 Madrid, Spain; (J.B.); (E.F.-C.); (J.M.S.-V.)
| | - Eduardo Fernández-Carrión
- VISAVET Health Surveillance Centre, Animal Health Department, Faculty of Veterinary Medicine, Complutense University of Madrid, 28040 Madrid, Spain; (J.B.); (E.F.-C.); (J.M.S.-V.)
| | - Javier Lucientes
- Department of Animal Pathology (Animal Health), AgriFood Institute of Aragón IA2, Faculty of Veterinary Medicine, University of Zaragoza, 50013 Zaragoza, Spain;
| | - José Manuel Sánchez-Vizcaíno
- VISAVET Health Surveillance Centre, Animal Health Department, Faculty of Veterinary Medicine, Complutense University of Madrid, 28040 Madrid, Spain; (J.B.); (E.F.-C.); (J.M.S.-V.)
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10
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Belkharchouche M, Berchi S, Mathieu B, Rakotoarivony I, Duhayon M, Baldet T, Balenghien T. Update of the Culicoides (Diptera: Ceratopogonidae) species checklist from Algeria with 10 new records. Parasit Vectors 2020; 13:463. [PMID: 32912306 PMCID: PMC7488159 DOI: 10.1186/s13071-020-04335-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/01/2020] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND The Culicoides fauna of Algeria has been historically investigated, leading to the description of many new species by Kieffer in the 1920s, Clastrier in the 1950s or Callot in the 1960s and to a comprehensive inventory by Szadziewski in the 1980s. The emergence of bluetongue in the late 1990s enhanced Culicoides collections made in the country over the last two decades, but information remained mostly unpublished. The aim of this study is therefore to provide a comprehensive and updated checklist of Culicoides biting midge species in Algeria. METHODS The literature (published and grey, in French and in English) from 1920 to date on Culicoides collections in Algeria was collected and analyzed in the light of the current taxonomic and systematic knowledge and methods. Fresh Culicoides material was also analyzed using light/suction trap collections carried out from November 2015 to September 2018 in nine localities of the 'wilayah' of Tiaret (northwestern Algeria). Slide mounted specimens were identified morphologically using the interactive identification key IIKC and original descriptions. Specimens were then compared with non-type material originating from different countries and partly with type material. RESULTS A total of 13,709 Culicoides, belonging to at least 36 species within 10 subgenera, were examined leading to 10 new records in Algeria, including C. chiopterus, C. dewulfi, C. navaiae, C. grisescens, C. paradoxalis, C. shaklawensis, C. simulator, C. univittatus, C. achrayi and C. picturatus. These new records and all previous records provided by the literature review were discussed. CONCLUSIONS We propose a Culicoides checklist for the Algerian fauna of 59 valid species, including species mainly with a large Palaearctic distribution and a specific Mediterranean distribution, and only a few species from the Afrotropical region. Among them, several species, mainly of the subgenera Avaritia and Culicoides, are confirmed or probable vectors of arboviruses important in animal health.
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Affiliation(s)
- Mounira Belkharchouche
- Ecole Nationale Supérieure de Biotechnologie, Taoufik Khaznadar, nouveau pôle universitaire Ali Mendjeli, B.P. E66, 25100 Constantine, Algérie
- Faculté des Sciences de la Nature et de la Vie, Université Ibn Khaldoun, B.P.75 Zaaroura, Tiaret, 1400 Algérie
- Laboratoire de Biosystématique et Ecologie des Arthropodes, Faculté des Sciences de la Nature et de la Vie, Département de Biologie Animale, Université Frères Mentouri, Constantine 1, 2500 Algérie
- CIRAD, UMR ASTRE, 34398 Montpellier, France
| | - Selima Berchi
- Laboratoire de Biosystématique et Ecologie des Arthropodes, Faculté des Sciences de la Nature et de la Vie, Département de Biologie Animale, Université Frères Mentouri, Constantine 1, 2500 Algérie
| | - Bruno Mathieu
- Institut de Parasitologie et de Pathologies Tropicales de Strasbourg (IPPTS), UR 7292, 3 Rue Koeberlé, 67000 Strasbourg, France
| | - Ignace Rakotoarivony
- CIRAD, UMR ASTRE, 34398 Montpellier, France
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
| | - Maxime Duhayon
- CIRAD, UMR ASTRE, 34398 Montpellier, France
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
| | - Thierry Baldet
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
- CIRAD, UMR ASTRE, 97491 Sainte-Clotilde, La Réunion France
| | - Thomas Balenghien
- ASTRE, University of Montpellier, CIRAD, INRAE, Montpellier, France
- CIRAD, UMR ASTRE, 10101 Rabat, Morocco
- Institut Agronomique et Vétérinaire Hassan II, Unité Microbiologie, Immunologie et Maladies Contagieuses, 10100 Rabat, Morocco
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Harsha R, Mazumdar SM, Mazumdar A. Abundance, diversity and temporal activity of adult Culicoides spp. associated with cattle in West Bengal, India. Med Vet Entomol 2020; 34:327-343. [PMID: 32357384 DOI: 10.1111/mve.12446] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 03/21/2020] [Accepted: 04/04/2020] [Indexed: 06/11/2023]
Abstract
Relative abundance, species composition and temporal activity of Culicoides midges were studied for a period of 2 years (2012-2014) using suction ultra violet light traps at two sites located in the agriculture heartland of West Bengal, India. Surveillance in close proximity to cattle recorded predominance of five species with C oxystoma and C. peregrinus as the most dominant species followed by C. fulvus, C. innoxius and C. anophelis. The temporal activity of midges was investigated for seven consecutive nights at one site in August-September, 2012 and the predominant species was Culicoides oxystoma followed by Culicoides peregrinus. All of the species exhibited crepuscular activity with their flight activity increasing from dusk to dawn. Engorged adults constituted dominant age group in collections. Studies on population ecology of the adults midges are of considerable importance predicting for the epidemicity of midge-borne diseases in cattle.
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Affiliation(s)
- R Harsha
- Department of Zoology, Balurghat College, Balurghat, West Bengal, India
| | - S M Mazumdar
- Department of Zoology, The University of Burdwan, Burdwan, West Bengal, India
| | - A Mazumdar
- Department of Zoology, The University of Burdwan, Burdwan, West Bengal, India
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12
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Becker ME, Roberts J, Schroeder ME, Gentry G, Foil LD. Prospective Study of Epizootic Hemorrhagic Disease Virus and Bluetongue Virus Transmission in Captive Ruminants. J Med Entomol 2020; 57:1277-1285. [PMID: 32083292 DOI: 10.1093/jme/tjaa027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Indexed: 06/10/2023]
Abstract
Bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) cause hemorrhagic disease (HD) in wild ruminants and bluetongue disease (BT) and epizootic hemorrhagic disease (EHD) in livestock. These viruses are transmitted by biting midges in the genus Culicoides (family Ceratopogonidae). Mortality from this disease can reach 90% in certain breeds of sheep and in white-tailed deer (Odocoileus virginianus). From January until December of 2012, we conducted a prospective study to determine the origin and routes of transmission of BTV and EHDV in captive deer and cattle. The objective was to determine the abundance of Culicoides spp. and BTV/EHDV infection prevalence in midges, cattle, and deer in an area experiencing an outbreak of BT and EHD. Agar gel immunodiffusion (AGID) tests to detect for EHDV and BTV antibodies were conducted on serum collected from cattle and deer, quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) was utilized for BTV/EHDV RNA detection in tissues from dead deer, and CDC miniature black light traps baited with dry ice were deployed to capture insects. The AGID results showed 19 out of 29 cattle and 18 out of 58 white-tailed deer seroconverted for these viruses during the vector season. Tradition gel-based reverse transcriptase polymerase chain reaction was utilized to determine serotype. Sixteen cows were positive for EHDV-2, EHDV-6, or BTV-12 and 15 deer positive for EHDV-1, EHDV-6, or BTV-12. Specimens from 14 species of Culicoides (Dptera: Ceratopogonidae) (Culicoides arboricola Root and Hoffman, Culicoides biguttatus Coquillett, Culicoides crepuscularis Malloch, Culicoides debilipalpis Lutz, Culicoides furens Poey, Culicoides haematopotus Malloch, Culicoides hinmani Khalaf, Culicoides nanus Root and Hoffman, Culicoides neopulicaris Wirth, Culicoides paraensis Goeldi, Culicoides stellifer Coquillet, Culicoides variipennis Coquillet, Culicoides villosipennis Root and Hoffman, and Culicoides venustus Hoffman) were captured and tested for BTV and EHDV using RT-qPCR assays. BTV viral nucleic acid was detected in three pools from three different species of midges: C. crepuscularis, C. debilipalpis, and C. stellifer.
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Affiliation(s)
- Michael E Becker
- Department of Entomology, Louisiana State University Agricultural Center, Agricultural Experiment Station, Life Sciences, Baton Rouge, LA
| | - Jonathan Roberts
- Louisiana Department of Agriculture and Forestry, LSU Union Square, Baton Rouge, LA
| | - Megan E Schroeder
- Texas A&M Veterinary Medical Diagnostic Laboratory, College Station, TX
| | - Glen Gentry
- Louisiana State University Agricultural Center, Agricultural Experiment Station, Bob R. Jones Idlewild Research Station, Idlewild Drive, Clinton, LA
| | - Lane D Foil
- Department of Entomology, Louisiana State University Agricultural Center, Agricultural Experiment Station, Life Sciences, Baton Rouge, LA
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13
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Aguilar-Vega C, Fernández-Carrión E, Lucientes J, Sánchez-Vizcaíno JM. A model for the assessment of bluetongue virus serotype 1 persistence in Spain. PLoS One 2020; 15:e0232534. [PMID: 32353863 PMCID: PMC7192634 DOI: 10.1371/journal.pone.0232534] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 04/16/2020] [Indexed: 11/23/2022] Open
Abstract
Bluetongue virus (BTV) is an arbovirus of ruminants that has been circulating in Europe continuously for more than two decades and has become endemic in some countries such as Spain. Spain is ideal for BTV epidemiological studies since BTV outbreaks from different sources and serotypes have occurred continuously there since 2000; BTV-1 has been reported there from 2007 to 2017. Here we develop a model for BTV-1 endemic scenario to estimate the risk of an area becoming endemic, as well as to identify the most influential factors for BTV-1 persistence. We created abundance maps at 1-km2 spatial resolution for the main vectors in Spain, Culicoides imicola and Obsoletus and Pulicaris complexes, by combining environmental satellite data with occurrence models and a random forest machine learning algorithm. The endemic model included vector abundance and host-related variables (farm density). The three most relevant variables in the endemic model were the abundance of C. imicola and Obsoletus complex and density of goat farms (AUC 0.86); this model suggests that BTV-1 is more likely to become endemic in central and southwestern regions of Spain. It only requires host- and vector-related variables to identify areas at greater risk of becoming endemic for bluetongue. Our results highlight the importance of suitable Culicoides spp. prediction maps for bluetongue epidemiological studies and decision-making about control and eradication measures.
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Affiliation(s)
- Cecilia Aguilar-Vega
- VISAVET Health Surveillance Centre, Animal Health Department, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
| | - Eduardo Fernández-Carrión
- VISAVET Health Surveillance Centre, Animal Health Department, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
| | - Javier Lucientes
- Department of Animal Pathology (Animal Health), AgriFood Institute of Aragón IA2, Faculty of Veterinary Medicine, University of Zaragoza, Zaragoza, Spain
| | - José Manuel Sánchez-Vizcaíno
- VISAVET Health Surveillance Centre, Animal Health Department, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain
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14
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Hakima B, Hwang HS, Lee KY. Molecular identification of Culicoides (Diptera: Ceratopogonidae) species in Algeria. Acta Trop 2020; 202:105261. [PMID: 31705843 DOI: 10.1016/j.actatropica.2019.105261] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 05/07/2019] [Accepted: 11/05/2019] [Indexed: 11/19/2022]
Abstract
Bluetongue is a serious vector-borne viral disease that infects wild and domestic ruminants. The causative virus is transmitted by midges of the genus Culicoides, which consists of at least 1350 species worldwide. Since 1998, bluetongue disease has spread to Europe and northern Africa, including Algeria. To better understand the distribution of Culicoides species in Algeria, adult midges were collected from 17 different regions in Algeria from 2009 to 2015. At first, 492 specimens were grouped into 52 batches by wing patterns and geographic area of Algeria. Analysis of 60 nucleotide sequences of the mitochondrial cytochrome oxidase subunit I (COI) gene showed that the presence of 14 species including five unknown species, which were belonged to seven distinct subgenera. At least five species (C. imicola, C. obsoletus, C. puncticollis, C. kingi, and C. newsteadi) were discussed as potential vectors of bluetongue virus (BTV). The present study provides important insights into the genetic diversity of Culicoides and the potential spread of BTV in Algeria.
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Affiliation(s)
- Berrayah Hakima
- Parasitology and Histology Laboratory, Central Veterinary Laboratory of Algiers, Algerian National Institute of Veterinary Medicine, Algeria; Division of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu, Republic of Korea
| | - Hwal-Su Hwang
- Division of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu, Republic of Korea
| | - Kyeong-Yeoll Lee
- Division of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu, Republic of Korea; Institute of Plant Medicine, Kyungpook National University, Daegu, Republic of Korea; Agricultural Science and Technology Institute, Kyungpook National University, Daegu, Republic of Korea.
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15
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Rajko-Nenow P, Christodoulou V, Thurston W, Ropiak HM, Savva S, Brown H, Qureshi M, Alvanitopoulos K, Gubbins S, Flannery J, Batten C. Origin of Bluetongue Virus Serotype 8 Outbreak in Cyprus, September 2016. Viruses 2020; 12:E96. [PMID: 31947695 PMCID: PMC7019704 DOI: 10.3390/v12010096] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 12/12/2022] Open
Abstract
In September 2016, clinical signs, indicative of bluetongue, were observed in sheep in Cyprus. Bluetongue virus serotype 8 (BTV-8) was detected in sheep, indicating the first incursion of this serotype into Cyprus. Following virus propagation, Nextera XT DNA libraries were sequenced on the MiSeq instrument. Full-genome sequences were obtained for five isolates CYP2016/01-05 and the percent of nucleotide sequence (% nt) identity between them ranged from 99.92% to 99.95%, which corresponded to a few (2-5) amino acid changes. Based on the complete coding sequence, the Israeli ISR2008/13 (98.42-98.45%) was recognised as the closest relative to CYP2016/01-05. However, the phylogenetic reconstruction of CYP2016/01-05 revealed that the possibility of reassortment in several segments: 4, 7, 9 and 10. Based on the available sequencing data, the incursion BTV-8 into Cyprus most likely occurred from the neighbouring countries (e.g., Israel, Lebanon, Syria, or Jordan), where multiple BTV serotypes were co-circulating rather than from Europe (e.g., France) where a single BTV-8 serotype was dominant. Supporting this hypothesis, atmospheric dispersion modelling identified wind-transport events during July-September that could have allowed the introduction of BTV-8 infected midges from Lebanon, Syria or Israel coastlines into the Larnaca region of Cyprus.
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Affiliation(s)
- Paulina Rajko-Nenow
- Pirbright Institute, Woking, Surrey GU24 0NF, UK (H.B.); (M.Q.); (S.G.); (J.F.); (C.B.)
| | | | | | - Honorata M. Ropiak
- Pirbright Institute, Woking, Surrey GU24 0NF, UK (H.B.); (M.Q.); (S.G.); (J.F.); (C.B.)
| | - Savvas Savva
- Veterinary Services of Cyprus, Nicosia 1417, Cyprus; (V.C.); (S.S.); (K.A.)
| | - Hannah Brown
- Pirbright Institute, Woking, Surrey GU24 0NF, UK (H.B.); (M.Q.); (S.G.); (J.F.); (C.B.)
| | - Mehnaz Qureshi
- Pirbright Institute, Woking, Surrey GU24 0NF, UK (H.B.); (M.Q.); (S.G.); (J.F.); (C.B.)
| | | | - Simon Gubbins
- Pirbright Institute, Woking, Surrey GU24 0NF, UK (H.B.); (M.Q.); (S.G.); (J.F.); (C.B.)
| | - John Flannery
- Pirbright Institute, Woking, Surrey GU24 0NF, UK (H.B.); (M.Q.); (S.G.); (J.F.); (C.B.)
| | - Carrie Batten
- Pirbright Institute, Woking, Surrey GU24 0NF, UK (H.B.); (M.Q.); (S.G.); (J.F.); (C.B.)
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16
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Duan YL, Bellis G, Li L, Li HC, Miao HS, Kou ML, Liao DF, Wang Z, Gao L, Li JZ. Potential vectors of bluetongue virus in high altitude areas of Yunnan Province, China. Parasit Vectors 2019; 12:464. [PMID: 31585545 PMCID: PMC6778386 DOI: 10.1186/s13071-019-3736-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 09/30/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bluetongue disease of ruminants is a typical insect-borne disease caused by bluetongue virus (BTV) of the genus Orbivirus (family Reoviridae) and transmitted by some species of Culicoides (Diptera: Ceratopogonidae). Recently, the detection of BTV in yaks in high altitude meadows of the Shangri-La district of Yunnan Province, China, prompted an investigation of the Culicoides fauna as potential vectors of BTV. METHODS A total of 806 Culicoides midges were collected by light trapping at three sites at altitudes ranging from 1800 to 3300 m. The species were identified based on morphology and the DNA sequences of cytochrome c oxidase subunit 1 (cox1). PCR and quantitative PCR following reverse transcription were used to test for the presence of BTV RNA in Culicoides spp. A phylogenetic analysis was used to analyze the cox1 sequences of some specimens. RESULTS Four species dominated these collections and cox1 barcoding revealed that at least two of these appear to belong to species new to science. Culicoides tainanus and a cryptic species morphologically similar to C. tainanus dominated low altitude valley collections while C. nielamensis was the most abundant species in the high-altitude meadow. A species related to C. obsoletus occurred at all altitudes but did not dominate any of the collections. BTV RT-qPCR analysis detected BTV RNA in two specimens of C. tainanus, in one specimen closely related to C. tainanus and in one specimen closely related to C. obsoletus by barcode sequencing. CONCLUSIONS This study suggests that BTV in high altitude areas of Yunnan is being transmitted by three species of Culicoides, two of which appear to be new to science. This research may be useful in improving understanding of the effects of global warming on arboviral disease epidemiology and further study is important in research into disease control and prevention.
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Affiliation(s)
- Ying Liang Duan
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan Province China
| | - Glenn Bellis
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, NT Australia
| | - Le Li
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan Province China
| | - Hua Chun Li
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan Province China
| | - Hai Sheng Miao
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan Province China
| | - Mei Ling Kou
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan Province China
| | - De Fang Liao
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan Province China
| | - Zheng Wang
- Zhongdian Animal Disease Control Center, Shangri-La, Yunnan Province China
| | - Lin Gao
- Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Yunnan Animal Science and Veterinary Institute, Kunming, Yunnan Province China
| | - Ji Zhong Li
- Zhongdian Animal Disease Control Center, Shangri-La, Yunnan Province China
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Murchie AK, Thompson GM, Clawson S, Brown A, Gordon AW, Jess S. Field Evaluation of Deltamethrin and Ivermectin Applications to Cattle on Culicoides Host-Alighting, Blood-Feeding, and Emergence. Viruses 2019; 11:E731. [PMID: 31398840 PMCID: PMC6722592 DOI: 10.3390/v11080731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/30/2019] [Accepted: 08/02/2019] [Indexed: 11/16/2022] Open
Abstract
The impact of topical applications of deltamethrin and ivermectin to cattle on Culicoides spp. landing and blood-feeding was studied in this work using sticky traps mounted on Friesian heifers' backs. There was no effect of the insecticides on total numbers of Culicoides trapped or the proportion engorged. Deltamethrin and ivermectin treatment did not prevent blood-feeding on these animals. Deltamethrin did result in significant Culicoides mortality as evidenced by the numbers of dead midges combed from heifers' upper flanks. The proximity of engorged midges on traps to dead midges in the hair suggests that blood-feeding took place despite midges receiving an ultimately lethal dose of deltamethrin. Ivermectin application resulted in a smaller proportion of nulliparous than parous females caught. There was no significant effect of ivermectin on the numbers of Culicoides that emerged from dung samples (but p was small at 0.095 for the Obsoletus group Culicoides). In cases of suspect animal imports, pour-on or spray applications of deltamethrin could reduce the risk of onward transmission of bluetongue virus.
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Affiliation(s)
- Archie K Murchie
- Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, Northern Ireland, UK.
| | - Geoff M Thompson
- Ulster Farmers' Union, 475 Antrim Road, Belfast BT15 3DA, Northern Ireland, UK
| | - Sam Clawson
- Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, Northern Ireland, UK
| | - Andrew Brown
- Agri-Food and Biosciences Institute, Large Park, Hillsborough BT26 6DR, Northern Ireland, UK
| | - Alan W Gordon
- Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, Northern Ireland, UK
| | - Stephen Jess
- Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX, Northern Ireland, UK
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Maclachlan NJ, Zientara S, Wilson WC, Richt JA, Savini G. Bluetongue and epizootic hemorrhagic disease viruses: recent developments with these globally re-emerging arboviral infections of ruminants. Curr Opin Virol 2019; 34:56-62. [PMID: 30654271 DOI: 10.1016/j.coviro.2018.12.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 12/11/2018] [Indexed: 11/19/2022]
Abstract
Bluetongue (BT) and epizootic hemorrhagic disease (EHD) are globally re-emerging diseases of domestic and wild ruminants, respectively caused by BT virus (BTV) and EHD virus. Both viruses are transmitted by hematophagous midges; however, newly recognized BTV serotypes may be transmitted horizontally without requirement for any biological vector. The global range of these viruses and/or their associated diseases have changed remarkably in recent years, most notably with the invasion of Europe by multiple serotypes of BTV since 1998. Although not zoonoses, the unanticipated emergence of BT and EHD in several different areas of the world provides a uniquely sobering and unambiguous reminder of the potential consequences of climate change on the distribution and severity of vector-borne diseases. Recent experiences with these viruses have also emphasized the need for effective, DIVA-compatible vaccines to combat anticipated future incursions, as existing vaccines have serious inherent deficiencies.
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Affiliation(s)
- Nigel James Maclachlan
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
| | - Stephan Zientara
- UMR VIROLOGIE, INRA, Ecole Nationale Vétérinaire d'Alfort, ANSES, Université Paris-Est, Maisons-Alfort 94700, France
| | - William C Wilson
- Arthropod-Borne Animal Diseases Research Unit, Agricultural Research Service, USDA, Manhattan, KS, USA
| | - Juergen A Richt
- Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Giovanni Savini
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise, OIE Reference Laboratory for BTV, Teramo, Italy
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Abstract
There is a solid theoretical basis for expecting climate change to have a considerable effect on the infectious diseases of humans, animals and plants. Vector-borne diseases are the most likely to be affected. It is, however, rare to observe such impacts, as diseases are also influenced by many other drivers, some of which may have stronger effects over shorter time scales than climate change. Nevertheless, there is evidence that our warming climate has already influenced some animal diseases, of which bluetongue is considered a prime example. Bluetongue emerged dramatically in southern Europe after 1998 and in northern Europe from 2006. While the speed and scale of this emergence is a challenge to explain, there is evidence, principally from the development of climate-driven models, that recent climate change has played a significant role. Climate-driven models point to an increase in the risk of bluetongue transmission in Europe in recent decades, caused by an increased suitability of parts of southern Europe for the Afro-tropical biting midge, Culicoides imicola, as well as an increase in the vectorial capacity of indigenous Culicoides vectors in northern Europe. Farm-to-farm transmission models of bluetongue in England and Wales under predicted climatic conditions further suggest that, under high-emission scenarios, the scale of future outbreaks could far exceed those experienced to date. The role of climate change in the developing threat of animal disease is, therefore, likely to be economically and socially costly, unless lower emission targets can be set and followed.
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Fernández-Carrión E, Ivorra B, Ramos ÁM, Martínez-López B, Aguilar-Vega C, Sánchez-Vizcaíno JM. An advection-deposition-survival model to assess the risk of introduction of vector-borne diseases through the wind: Application to bluetongue outbreaks in Spain. PLoS One 2018; 13:e0194573. [PMID: 29566088 PMCID: PMC5864019 DOI: 10.1371/journal.pone.0194573] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 03/06/2018] [Indexed: 11/19/2022] Open
Abstract
This work develops a methodology for estimating risk of wind-borne introduction of flying insects into a country, identifying areas and periods of high risk of vector-borne diseases incursion. This risk can be characterized by the role of suitable temperatures and wind currents in small insects' survival and movements, respectively. The model predicts the number density of introduced insects over space and time based on three processes: the advection due to wind currents, the deposition on the ground and the survival due to climatic conditions. Spanish livestock has suffered many bluetongue outbreaks since 2004 and numerous experts point to Culicoides transported by wind from affected areas in North Africa as a possible cause. This work implements numerical experiments simulating the introduction of Culicoides in 2004. The model identified southern and eastern Spain, particularly between June and November, as being at greatest risk of wind-borne Culicoides introduction, which matches field data on bluetongue outbreaks in Spain this year. This validation suggests that this model may be useful for predicting introduction of airborne pathogens of significance to animal productivity.
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Affiliation(s)
- Eduardo Fernández-Carrión
- VISAVET Center and Animal Health Department, Veterinary School, Universidad Complutense de Madrid, Madrid, Spain
- * E-mail:
| | - Benjamin Ivorra
- MOMAT Research group, IMI-Institute and Applied Mathematics Department, Universidad Complutense de Madrid, Madrid, Spain
| | - Ángel Manuel Ramos
- MOMAT Research group, IMI-Institute and Applied Mathematics Department, Universidad Complutense de Madrid, Madrid, Spain
| | - Beatriz Martínez-López
- CADMS Center for Animal Disease Modeling and Surveillance, School of Veterinary Medicine, UC Davis, Davis, California, United States of America
| | - Cecilia Aguilar-Vega
- VISAVET Center and Animal Health Department, Veterinary School, Universidad Complutense de Madrid, Madrid, Spain
| | - José Manuel Sánchez-Vizcaíno
- VISAVET Center and Animal Health Department, Veterinary School, Universidad Complutense de Madrid, Madrid, Spain
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Magliano A, Scaramozzino P, Ravagnan S, Montarsi F, DA Rold G, Cincinelli G, Moni A, Silvestri P, Carvelli A, DE Liberato C. Indoor and outdoor winter activity of Culicoides biting midges, vectors of bluetongue virus, in Italy. Med Vet Entomol 2018; 32:70-77. [PMID: 28833269 DOI: 10.1111/mve.12260] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 06/19/2017] [Accepted: 07/03/2017] [Indexed: 06/07/2023]
Abstract
Indoor and outdoor winter activity of Culicoides spp. (Diptera: Ceratopogonidae) in central Italy was investigated in order to evaluate whether indoor activity might account for the overwintering of bluetongue virus, as has been hypothesized by some authors. Weekly Culicoides collections were performed at three farms over three consecutive winter seasons. At each farm, two black-light traps were operated simultaneously, indoors and outdoors. Culicoides were identified using both morphological and molecular means. The Culicoides obsoletus group accounted for 98.2% of sampled specimens. Within this group, C. obsoletus s.s. accounted for 56.8% and Culicoides scoticus for 43.2% of samples. Nulliparous, parous and engorged females were caught throughout the entire winter, both indoors and outdoors. At times, indoor catch sizes outnumbered outdoor collections. A significant inverse correlation was found between minimum temperature and the proportion of indoor Culicoides of the total midge catch, thus indicating that lower outdoor temperatures drive Culicoides midges indoors. High rates of engorged females were recorded indoors, possibly as the result of the propensity of C. obsoletus females to feed indoors. Higher proportions of parous females were found in indoor than in outdoor catches, indicating higher survival rates indoors and, consequently, higher vectorial capacities of midges sheltering indoors compared with those remaining outdoors.
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Affiliation(s)
- A Magliano
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri', Rome, Italy
| | - P Scaramozzino
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri', Rome, Italy
| | - S Ravagnan
- Istituto Zooprofilattico Sperimentale delle Venezie, Rome, Italy
| | - F Montarsi
- Istituto Zooprofilattico Sperimentale delle Venezie, Rome, Italy
| | - G DA Rold
- Istituto Zooprofilattico Sperimentale delle Venezie, Rome, Italy
| | - G Cincinelli
- Azienda Unita' Sanitaria Locale (USL) Toscana Sud Est, Arezzo, Italy
| | - A Moni
- Azienda USL Toscana Nord Ovest, Massa Carrara, Italy
| | - P Silvestri
- Azienda Sanitaria Locale (ASL) Rieti, Rieti, Italy
| | - A Carvelli
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri', Rome, Italy
| | - C DE Liberato
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri', Rome, Italy
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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: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Mukhopadhyay E, Hazra S, Saha GK, Banerjee D. Altitudinal variation and bio-climatic variables influencing the potential distribution of Culicoides orientalis Macfie, 1932, suspected vector of Bluetongue virus across the North Eastern Himalayan belt of Sikkim. Acta Trop 2017; 176:402-411. [PMID: 28935556 DOI: 10.1016/j.actatropica.2017.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 09/10/2017] [Accepted: 09/16/2017] [Indexed: 11/18/2022]
Abstract
Culicoides orientalis was first recorded from Sikkim, in the year 1963, but no evidence based disease outbreak were available. In the last 50 years, 260 Bluetongue disease outbreaks caused by Culicoides species have been evidenced from India. Moreover, in recent years with increase of average temperature worldwide and increase in longevity of arthropod vectors like Culicoides along with a geographical range shift to new suitable warmer regions has increased the potentiality of vector borne disease outbreak throughout the world. The Himalayan range of Sikkim in India is a biodiversity hotspot and is extremely sensitive to such global climate changes. An attempt has been made to evaluate the altitude, climate and environmental data on selected study sites of Sikkim for a period of two years (2014-2015) for discerning potential distribution of C.orientalis in this region. The altitude, temperature, precipitation and potential distribution range maps of C. orientalis showed the areas of highest species abundance within the altitudinal range of 550-1830m, with some species extending its range up to 3750m, with average precipitation of 2010-2590mm and mean temperature of 11-18°C. The Maximum Entropy Modelling (MaxEnt) and the Jackknife test of the MaxEnt model further revealed that the major contributing factors governing C. orientalis distribution are annual precipitation (78.8%), followed by precipitation of driest quarter (8.3%) and mean temperature of the warmest quarter (3.3%). Accuracy of the study was evaluated by the area under the curve (AUC=0.860). The Biplot on F1-F2 axes (N=16, α=0.05) in the PCA showed the linear depiction of all the variables considered in our study, major contributors were annual precipitation, precipitation of driest quarter and mean temperature of warmest quarter being the primary factors governing species distribution, as analogous to results of the MaxEnt model. This study would help in developing strategies for monitoring and managing surveillance programmes to control the chances of disease spread to livestock animals and also validate the predictions on the eventual spread of the vector midges to higher altitudes of Sikkim.
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Affiliation(s)
- Emon Mukhopadhyay
- Diptera Section, Zoological Survey of India, M-Block, New Alipore, Kolkata, 700 053, India; Department of Zoology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700 019, India.
| | - Surajit Hazra
- Diptera Section, Zoological Survey of India, M-Block, New Alipore, Kolkata, 700 053, India
| | - Goutam Kumar Saha
- Department of Zoology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700 019, India
| | - Dhriti Banerjee
- Diptera Section, Zoological Survey of India, M-Block, New Alipore, Kolkata, 700 053, India
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Martínez-DE LA Puente J, Navarro J, Ferraguti M, Soriguer R, Figuerola J. First molecular identification of the vertebrate hosts of Culicoides imicola in Europe and a review of its blood-feeding patterns worldwide: implications for the transmission of bluetongue disease and African horse sickness. Med Vet Entomol 2017; 31:333-339. [PMID: 28748632 DOI: 10.1111/mve.12247] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 01/24/2017] [Accepted: 03/20/2017] [Indexed: 06/07/2023]
Abstract
Culicoides (Diptera: Ceratopogonidae) are vectors of pathogens that affect wildlife, livestock and, occasionally, humans. Culicoides imicola (Kieffer, 1913) is considered to be the main vector of the pathogens that cause bluetongue disease (BT) and African horse sickness (AHS) in southern Europe. The study of blood-feeding patterns in Culicoides is an essential step towards understanding the epidemiology of these pathogens. Molecular tools that increase the accuracy and sensitivity of traditional methods have been developed to identify the hosts of potential insect vectors. However, to the present group's knowledge, molecular studies that identify the hosts of C. imicola in Europe are lacking. The present study genetically characterizes the barcoding region of C. imicola trapped on farms in southern Spain and identifies its vertebrate hosts in the area. The report also reviews available information on the blood-feeding patterns of C. imicola worldwide. Culicoides imicola from Spain feed on blood of six mammals that include species known to be hosts of the BT and AHS viruses. This study provides evidence of the importance of livestock as sources of bloodmeals for C. imicola and the relevance of this species in the transmission of BT and AHS viruses in Europe.
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Affiliation(s)
- J Martínez-DE LA Puente
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (EBD-CSIC), Seville, Spain
- Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - J Navarro
- Departamento de Microbiología, Laboratorio de Producción y Sanidad Animal de Granada, Junta de Andalucía, Granada, Spain
| | - M Ferraguti
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (EBD-CSIC), Seville, Spain
| | - R Soriguer
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (EBD-CSIC), Seville, Spain
- Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - J Figuerola
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (EBD-CSIC), Seville, Spain
- Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
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Nicolas G, Tisseuil C, Conte A, Allepuz A, Pioz M, Lancelot R, Gilbert M. Environmental heterogeneity and variations in the velocity of bluetongue virus spread in six European epidemics. Prev Vet Med 2017; 149:1-9. [PMID: 29290289 DOI: 10.1016/j.prevetmed.2017.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 10/04/2017] [Accepted: 11/03/2017] [Indexed: 11/19/2022]
Abstract
Several epidemics caused by different bluetongue virus (BTV) serotypes occurred in European ruminants since the early 2000. Studies on the spatial distribution of these vector-borne infections and the main vector species highlighted contrasted eco-climatic regions characterized by different dominant vector species. However, little work was done regarding the factors associated with the velocity of these epidemics. In this study, we aimed to quantify and compare the velocity of BTV epidemic that have affected different European countries under contrasted eco-climatic conditions and to relate these estimates to spatial factors such as temperature and host density. We used the thin plate spline regression interpolation method in combination with trend surface analysis to quantify the local velocity of different epidemics that have affected France (BTV-8 2007-2008, BTV-1 2008-2009), Italy (BTV-1 2014), Andalusia in Spain (BTV-1 2007) and the Balkans (BTV-4 2014). We found significant differences in the local velocity of BTV spread according to the country and epidemics, ranging from 7.9km/week (BTV-1 2014 Italy) to 24.4km/week (BTV-1 2008 France). We quantify and discuss the effect of temperature and local host density on this velocity.
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Affiliation(s)
- Gaëlle Nicolas
- Spatial Epidemiology Lab (SpELL), Université Libre de Bruxelles, Brussels, Belgium.
| | - Clément Tisseuil
- Spatial Epidemiology Lab (SpELL), Université Libre de Bruxelles, Brussels, Belgium
| | - Annamaria Conte
- Istituto Zooprofilattico Sperimentaledell'Abruzzo e del Molise 'G. Caporale', Teramo, Italy
| | - Alberto Allepuz
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Barcelona, Spain
| | - Maryline Pioz
- INRA, UR 406 Abeilles et Environnement, Laboratoire Biologie et Protection de l'abeille, Site Agroparc, France
| | - Renaud Lancelot
- CIRAD, UMR ASTRE, Campus International de Baillarguet, Montpellier, France; INRA, UMR Astre1309, Campus International de Baillarguet, Montpellier, France
| | - Marius Gilbert
- Spatial Epidemiology Lab (SpELL), Université Libre de Bruxelles, Brussels, Belgium; Fonds National de la Recherche Scientifique (FNRS), Brussels, Belgium
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VAN DER Saag MR, Ward MP, Kirkland PD. Application of an embryonated chicken egg model to assess the vector competence of Australian Culicoides midges for bluetongue viruses. Med Vet Entomol 2017; 31:263-271. [PMID: 28429824 DOI: 10.1111/mve.12231] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 12/11/2016] [Accepted: 01/23/2017] [Indexed: 06/07/2023]
Abstract
Culicoides biting midges (Diptera: Ceratopogonidae) are vectors of a number of globally important arboviruses that affect livestock, including bluetongue virus (BTV), African horse sickness virus and the recently emerged Schmallenberg virus. In this study, a model using embryonated chicken eggs (ECEs) was utilized to undertake vector competence studies of Australian Culicoides spp. for 13 laboratory-adapted or wild-type virus strains of BTV. A total of 7393 Culicoides brevitarsis were reared from bovine dung, and 3364 Culicoides were induced to feed from ECEs infected with different strains of BTV. Of those, 911 (27%) survived the putative extrinsic incubation period of 9-12 days. In some trials, virus was also transmitted onward to uninfected ECEs, completing the transmission cycle. This model does not rely on the use of colonized midges and has the capacity to assess the vector competence of field-collected insects with strains of virus that have not previously been passaged in laboratory culture systems. There is also potential for this model to be used in investigations of the competence of Culicoides spp. for other arboviruses.
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Affiliation(s)
- M R VAN DER Saag
- Virology Laboratory, Elizabeth Macarthur Agricultural Institute, New South Wales Department of Primary Industries, Menangle, NSW, Australia
- Farm Animal and Veterinary Public Health, Faculty of Veterinary Science, University of Sydney, Camden, NSW, Australia
| | - M P Ward
- Farm Animal and Veterinary Public Health, Faculty of Veterinary Science, University of Sydney, Camden, NSW, Australia
| | - P D Kirkland
- Virology Laboratory, Elizabeth Macarthur Agricultural Institute, New South Wales Department of Primary Industries, Menangle, NSW, Australia
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Burgin L, Ekström M, Dessai S. Combining dispersion modelling with synoptic patterns to understand the wind-borne transport into the UK of the bluetongue disease vector. Int J Biometeorol 2017; 61:1233-1245. [PMID: 28091855 DOI: 10.1007/s00484-016-1301-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/16/2016] [Accepted: 12/17/2016] [Indexed: 06/06/2023]
Abstract
Bluetongue, an economically important animal disease, can be spread over long distances by carriage of insect vectors (Culicoides biting midges) on the wind. The weather conditions which influence the midge's flight are controlled by synoptic scale atmospheric circulations. A method is proposed that links wind-borne dispersion of the insects to synoptic circulation through the use of a dispersion model in combination with principal component analysis (PCA) and cluster analysis. We illustrate how to identify the main synoptic situations present during times of midge incursions into the UK from the European continent. A PCA was conducted on high-pass-filtered mean sea-level pressure data for a domain centred over north-west Europe from 2005 to 2007. A clustering algorithm applied to the PCA scores indicated the data should be divided into five classes for which averages were calculated, providing a classification of the main synoptic types present. Midge incursion events were found to mainly occur in two synoptic categories; 64.8% were associated with a pattern displaying a pressure gradient over the North Atlantic leading to moderate south-westerly flow over the UK and 17.9% of the events occurred when high pressure dominated the region leading to south-easterly or easterly winds. The winds indicated by the pressure maps generally compared well against observations from a surface station and analysis charts. This technique could be used to assess frequency and timings of incursions of virus into new areas on seasonal and decadal timescales, currently not possible with other dispersion or biological modelling methods.
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Affiliation(s)
| | - Marie Ekström
- CSIRO Land and Water, Black Mountain, GPO Box 1700, Canberra, 2601, ACT, Australia.
| | - Suraje Dessai
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
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Sarvašová A, Kočišová A, Liptáková E, Hiavatá H, Mathieu B. First insights into indoor and outdoor Culicoides activity related to the risk period for Bluetongue virus transmission in Eastern Slovakia. Acta Parasitol 2016; 61:743-755. [PMID: 27787226 DOI: 10.1515/ap-2016-0103] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 06/21/2016] [Indexed: 11/15/2022]
Abstract
The epizootic of Bluetongue virus (BTV) throughout Europe in 2006 revealed insufficient knowledge regarding seasonal activities, endo/exophilic and endo/exophagic behaviour of the species of the Culicoides genus (Diptera: Ceratopogonidae). Although several studies have been carried out in Western Europe, bringing new knowledge of the above mentioned topics, there was still a gap to fill in Central Europe. Therefore, this study investigated seasonal variations in the indoor/outdoor Culicoides activity observed in the south-eastern Slovakia from 2012 to 2014, using a light-trapping method. In total, 52,741 Culicoides were collected and identified; majority of them were caught outdoors (82.6%), with the highest activity period being mid-June. The C. obsoletus/C. scoticus and C.punctatus species predominated, altogether representing 88.8 and 94.1% of the total indoor and outdoor collections, respectively. Positive correlation was observed between the temperature and the abundance, whereas no correlation with other studied factors was detected. In autumn, Culicoides activity was observed outdoors at temperatures ranging between-1.5°C and 9.3°C, whereas the indoor activity was detected at temperatures ranging between-3.9°C and 0°C. This demonstrated that the most significant BTV vectors in the studied area are C. obsoletus/C. scoticus. The C. dewulfi and C. chiopterus vectors appeared to be of lower significance. The period with the highest risk of the BTV transmission in Eastern Slovakia appeared to be mid-June. The autumnal Culicoides activity inside the cowsheds may be important for the assessment of virus overwintering. This study is the first to provide the data on indoor/outdoor behaviour of biting midges in Slovakia.
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Conte A, Goffredo M, Candeloro L, Calistri P, Curci G, Colaiuda V, Quaglia M, Mancini G, Santilli A, Di Lorenzo A, Tora S, Savini L, Savini G. Analysis of climatic factors involved in the BTV-1 incursion in Central Italy in 2014. Vet Ital 2016; 52:223-229. [PMID: 27723030 DOI: 10.12834/vetit.69.198.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In 2012, six years after the previous epidemic, Bluetongue virus serotype 1 (BTV-1) re-emerged in Sardinia causing a limited number of outbreaks. Due to impossibility of implementing a vaccination campaign, the BTV-1 then spread all over the island in 2013 with about 7,000 outbreaks and, in September 2013, the virus reached Central Italy, with a limited number of outbreaks located along the Tyrrhenian coast. The surveillance system in place in Italy detected viral circulation during the following winter, when a few seroconversions were notified. Starting from mid July 2014, a huge number of outbreaks were reported and the disease spread toward inland territories, affecting Umbria, Abruzzo and Marche. In 2014, BTV-1 affected areas where Culicoides species belonging to the Obsoletus and Pulicaris complexes were identified as main vectors. The analysis of temperature and rainfall in Central Italy revealed a significant warmer winter (2013-2014) and a cooler and rainy summer season (2014). These climatic aspects might have certainly favored the overwintering of the virus in local vector or host populations in the Tyrrhenian coast, and, then, the spread of the virus to the rest of Central Italy. However, the heavy circulation of BTV-1 and the severity of clinical outbreaks recorded leave a number of 'open questions' that are currently under investigations.
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Affiliation(s)
- Annamaria Conte
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale'
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Brand SPC, Rock KS, Keeling MJ. The Interaction between Vector Life History and Short Vector Life in Vector-Borne Disease Transmission and Control. PLoS Comput Biol 2016; 12:e1004837. [PMID: 27128163 PMCID: PMC4851302 DOI: 10.1371/journal.pcbi.1004837] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 02/29/2016] [Indexed: 11/25/2022] Open
Abstract
Epidemiological modelling has a vital role to play in policy planning and prediction for the control of vectors, and hence the subsequent control of vector-borne diseases. To decide between competing policies requires models that can generate accurate predictions, which in turn requires accurate knowledge of vector natural histories. Here we highlight the importance of the distribution of times between life-history events, using short-lived midge species as an example. In particular we focus on the distribution of the extrinsic incubation period (EIP) which determines the time between infection and becoming infectious, and the distribution of the length of the gonotrophic cycle which determines the time between successful bites. We show how different assumptions for these periods can radically change the basic reproductive ratio (R0) of an infection and additionally the impact of vector control on the infection. These findings highlight the need for detailed entomological data, based on laboratory experiments and field data, to correctly construct the next-generation of policy-informing models. The basic reproductive ratio (R0) is a crucial measure of transmission intensity, lying at the interface between mathematical modelling and policy decision making. If control measures can induce a situation where R0 ≤ 1 for a sustained period of time then the pathogen must be eradicated. For diseases spread by short-lived insect vectors a modeller can not calculate R0 without addressing questions of chance such as, “What percentage of vectors will survive their extrinsic incubation period (EIP) to become infectious?”. Classical Ross-Macdonald theory provides answers for the modeller by making certain concrete assumptions, such as a fixed length EIP and exponentially distributed times between vector blood-meals. Using bluetongue virus spread by biting midges as an exemplar we demonstrate that biologically plausible alterations to the classical assumptions can significantly change the modeller’s prediction of R0 with both serious over-estimation and under-estimation being possible. The important modelling/control question, “How does R0 respond to increased vector per-capita mortality?”, is also found to depend strongly on details of the vector life-cycle expressed in the language of probability distributions.
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Affiliation(s)
- Samuel P. C. Brand
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
- WIDER (Warwick Infectious Disease Epidemiology Research) Centre, University of Warwick, Coventry, United Kingdom
- * E-mail:
| | - Kat S. Rock
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
- WIDER (Warwick Infectious Disease Epidemiology Research) Centre, University of Warwick, Coventry, United Kingdom
| | - Matt J. Keeling
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
- WIDER (Warwick Infectious Disease Epidemiology Research) Centre, University of Warwick, Coventry, United Kingdom
- Mathematics Institute, University of Warwick, Coventry, United Kingdom
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Napp S, Allepuz A, Purse BV, Casal J, García-Bocanegra I, Burgin LE, Searle KR. Understanding Spatio-Temporal Variability in the Reproduction Ratio of the Bluetongue (BTV-1) Epidemic in Southern Spain (Andalusia) in 2007 Using Epidemic Trees. PLoS One 2016; 11:e0151151. [PMID: 26963397 PMCID: PMC4786328 DOI: 10.1371/journal.pone.0151151] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 02/23/2016] [Indexed: 11/21/2022] Open
Abstract
Andalusia (Southern Spain) is considered one of the main routes of introduction of bluetongue virus (BTV) into Europe, evidenced by a devastating epidemic caused by BTV-1 in 2007. Understanding the pattern and the drivers of BTV-1 spread in Andalusia is critical for effective detection and control of future epidemics. A long-standing metric for quantifying the behaviour of infectious diseases is the case-reproduction ratio (Rt), defined as the average number of secondary cases arising from a single infected case at time t (for t>0). Here we apply a method using epidemic trees to estimate the between-herd case reproduction ratio directly from epidemic data allowing the spatial and temporal variability in transmission to be described. We then relate this variability to predictors describing the hosts, vectors and the environment to better understand why the epidemic spread more quickly in some regions or periods. The Rt value for the BTV-1 epidemic in Andalusia peaked in July at 4.6, at the start of the epidemic, then decreased to 2.2 by August, dropped below 1 by September (0.8), and by October it had decreased to 0.02. BTV spread was the consequence of both local transmission within established disease foci and BTV expansion to distant new areas (i.e. new foci), which resulted in a high variability in BTV transmission, not only among different areas, but particularly through time, which suggests that general control measures applied at broad spatial scales are unlikely to be effective. This high variability through time was probably due to the impact of temperature on BTV transmission, as evidenced by a reduction in the value of Rt by 0.0041 for every unit increase (day) in the extrinsic incubation period (EIP), which is itself directly dependent on temperature. Moreover, within the range of values at which BTV-1 transmission occurred in Andalusia (20.6°C to 29.5°C) there was a positive correlation between temperature and Rt values, although the relationship was not linear, probably as a result of the complex relationship between temperature and the different parameters affecting BTV transmission. Rt values for BTV-1 in Andalusia fell below the threshold of 1 when temperatures dropped below 21°C, a much higher threshold than that reported in other BTV outbreaks, such as the BTV-8 epidemic in Northern Europe. This divergence may be explained by differences in the adaptation to temperature of the main vectors of the BTV-1 epidemic in Andalusia (Culicoides imicola) compared those of the BTV-8 epidemic in Northern Europe (Culicoides obsoletus). Importantly, we found that BTV transmission (Rt value) increased significantly in areas with higher densities of sheep. Our analysis also established that control of BTV-1 in Andalusia was complicated by the simultaneous establishment of several distant foci at the start of the epidemic, which may have been caused by several independent introductions of infected vectors from the North of Africa. We discuss the implications of these findings for BTV surveillance and control in this region of Europe.
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Affiliation(s)
- S. Napp
- Centre de Recerca en Sanitat Animal (CReSA)—Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Campus UAB, 08193 Bellaterra, Barcelona, Spain
- * E-mail:
| | - A. Allepuz
- Centre de Recerca en Sanitat Animal (CReSA)—Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Campus UAB, 08193 Bellaterra, Barcelona, Spain
- Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Barcelona, Spain
| | - B. V. Purse
- Centre for Ecology and Hydrology, MacLean Bldg, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB, United Kingdom
| | - J. Casal
- Centre de Recerca en Sanitat Animal (CReSA)—Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Campus UAB, 08193 Bellaterra, Barcelona, Spain
- Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Barcelona, Spain
| | - I. García-Bocanegra
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Córdoba (UCO), Campus Universitario de Rabanales, 14071 Córdoba, Spain
| | - L. E. Burgin
- Met Office, FitzRoy Road, Exeter, Devon EX1 3PB United Kingdom
| | - K. R. Searle
- Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, United Kingdom
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Abstract
Summary Bluetongue (BT) is an arthropod-transmitted viral disease of non-African ungulates, principally sheep. The disease results from vascular injury analogous to that of human haemorrhagic viral fevers, with characteristic tissue infarction, haemorrhage, vascular leakage, oedema, and hypovolaemic shock. Importantly, BT is not zoonotic. Bluetongue virus (BTV) infection of ruminants and vector Culicoides midges is endemic throughout many tropical and temperate regions of the world; however, within this global range the virus exists within relatively discrete ecosystems (syn. episystems) where specific constellations of BTV serotypes are spread by different species of biting Culicoides midges. Recently discovered goat-associated BTVs, notably BTV serotype 25 (BTV-25) in central Europe, appear to have distinctive biological properties and an epidemiology that is not reliant on Culicoides midges as vectors for virus transmission. Bluetongue virus infection of ruminants is often subclinical, but outbreaks of severe disease occur regularly at the upper and lower limits of the virus's global range, where infection is distinctly seasonal. There have been recent regional alterations in the global distribution of BTV infection, particularly in Europe. It is proposed that climate change is responsible for these events through its impact on vector midges. However, the role of anthropogenic factors in mediating emergence of BTV into new areas remains poorly defined; for example, it is not clear to what extent anthropogenic factors were responsible for the recent translocation to northern and eastern Europe of live attenuated vaccine viruses and an especially virulent strain of BTV-8 with distinctive properties. Without thorough characterisation of all environmental and anthropogenic drivers of the recent emergence of BT in northern Europe and elsewhere, it is difficult to predict what the future holds in terms of global emergence of BTV infection. Accurate and convenient laboratory tests are available for the sensitive and specific serological and virological diagnosis of BTV infection and confirmation of BT in animals. Prevention and control strategies for BT are largely reactive in nature, and typically are reliant on vaccination of susceptible livestock and restrictions on animal trade and movement.
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Sedda L, Morley D, Brown HE. Characteristics of Wind-Infective Farms of the 2006 Bluetongue Serotype 8 Epidemic in Northern Europe. Ecohealth 2015; 12:461-467. [PMID: 25552249 DOI: 10.1007/s10393-014-1008-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 12/10/2014] [Accepted: 12/10/2014] [Indexed: 06/04/2023]
Abstract
Bluetongue is a Culicoides-borne viral disease of livestock. In 2006, northern Europe experienced a major outbreak of this disease with devastating effects on the livestock industry. The outbreak quickly spread over the region, primarily affecting cattle and sheep. A previous analysis of the role of vector flight and wind in the spread of this virus across northern Europe indicated that infection at 1,326 (65%) of the reported infected farms could be traced back to just 599 (29%) farms (wind-infective farms). Rather than focusing on presence or absence of vectors or difference between infected and non-infected farms, we investigate the zoological and environmental characteristics of these 599 wind-infective farms (which can be thought of as super-spreaders) in order to characterize what makes them distinct from non-infective farms. Differences in temperature, precipitation, and the density of sheep at individual farms were identified between these two groups. These environmental and zoological factors are known to affect vector abundance and may have promoted bluetongue virus transmission. Identifying such ecological differences can help in the description and quantification of relative risk in affected areas.
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Affiliation(s)
- Luigi Sedda
- Geography and Environment, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - David Morley
- Department of Epidemiology and Biostatistics, Faculty of Medicine, MRC-PHE Centre for Environment and Health, School of Public Health, Imperial College London, St. Mary's Campus, London, W2 1PG, UK
| | - Heidi E Brown
- Division of Epidemiology and Biostatistics, Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Ave., Tucson, AZ, 85724, USA.
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Harsha R, Pan B, Ghosh K, Mazumdar A. Isolation of haemolytic bacilli from field-collected Culicoides oxystoma and Culicoides peregrinus: potential vectors of bluetongue virus in West Bengal, India. Med Vet Entomol 2015; 29:210-214. [PMID: 25644315 DOI: 10.1111/mve.12097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 07/11/2014] [Accepted: 07/14/2014] [Indexed: 06/04/2023]
Abstract
Two haemolytic bacterial strains of Bacillus pumilus (CU1A, CU1B) and one blood-utilizing strain of Bacillus licheniformis (CU2B) were isolated from relatively low numbers of field-collected females of Culicoides oxystoma and Culicoides peregrinus (Diptera: Ceratopogonidae). A total of 36 females, including 18 of each of C. oxystoma and C. peregrinus (consisting of one and a pool of eight blood-engorged specimens, and one and a pool of eight non-engorged specimens for each species), were tested. In C. oxystoma, all three strains of bacteria were isolated from the one non-engorged, the pool of non-engorged and the pool of blood-engorged females tested, but CU1A and CU2B were not found in the one blood-engorged female tested. In C. peregrinus, all three strains were present in the pool of blood-engorged females. However, the strain CU2B was not found in the pool of non-engorged females. In the one blood-engorged and one non-engorged female tested, CU1A and CU2B were detected. The bacterial strains were identified based on Gram staining, enzyme activity (amylase and protease) and alignment of the 16S rRNA partial gene sequence to that available in the National Center for Biotechnology Information (NCBI) database GenBank. The functional role and significance of these haemolytic and blood-digesting bacteria within the genus Culicoides remain to be determined.
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Affiliation(s)
- R Harsha
- Entomology Research Unit, Department of Zoology, University of Burdwan, Burdwan, West Bengal, India
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Osborne CJ, Mayo CE, Mullens BA, McDermott EG, Gerry AC, Reisen WK, MacLachlan NJ. Lack of Evidence for Laboratory and Natural Vertical Transmission of Bluetongue Virus in Culicoides sonorensis (Diptera: Ceratopogonidae). J Med Entomol 2015; 52:274-7. [PMID: 26336312 PMCID: PMC4481717 DOI: 10.1093/jme/tju063] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 12/11/2014] [Indexed: 05/05/2023]
Abstract
Culicoides sonorensis (Wirth & Jones) is the principal North American vector of bluetongue virus (BTV). BTV infection of livestock is distinctly seasonal (late summer and fall) in temperate regions of the world such as California, which has led to speculation regarding vertical transmission of the virus within the midge vector as a potential mechanism for interseasonal maintenance ("overwintering") of the virus. To evaluate potential vertical transmission of BTV in its midge vector, we fed adult midges BTV-spiked blood and used a BTV-specific quantitative reverse transcriptase polymerase chain reaction assay to evaluate parent, egg, and progeny stages of laboratory-reared C. sonorensis for the presence of viral nucleic acid. Whereas BTV nucleic acid was weakly detected in egg batches of virus-fed female midges, virus was never detected in subsequent progeny stages (larvae, pupae, and F1 generation adults). Similarly, BTV was not detected in pools of larvae collected from the waste-water lagoon of a BTV-endemic dairy farm in northern California during the seasonal period of virus transmission. Collectively, these results indicate that BTV is not readily transmitted vertically in C. sonorensis, and that persistence of the virus in long-lived parous female midges is a more likely mechanism for overwintering of BTV in temperate regions.
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Affiliation(s)
- C J Osborne
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Ave., Davis, CA 95626
| | - C E Mayo
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Ave., Davis, CA 95626. Corresponding author, e-mail: . Current address: CSU-CVMBS-Veterinary Diagnostic Laboratory, Fort Collins, 300 W Drake Rd., VTH, Fort Collins, CO 80523-0001
| | - B A Mullens
- Department of Entomology, University of California, Riverside, 900 University Ave., Riverside, CA 92521
| | - E G McDermott
- Department of Entomology, University of California, Riverside, 900 University Ave., Riverside, CA 92521
| | - A C Gerry
- Department of Entomology, University of California, Riverside, 900 University Ave., Riverside, CA 92521
| | - W K Reisen
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Ave., Davis, CA 95626
| | - N J MacLachlan
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Ave., Davis, CA 95626
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Zimmer JY, Brostaux Y, Haubruge E, Francis F. Larval development sites of the main Culicoides species (Diptera: Ceratopogonidae) in northern Europe and distribution of coprophilic species larvae in Belgian pastures. Vet Parasitol 2014; 205:676-86. [PMID: 25241330 DOI: 10.1016/j.vetpar.2014.08.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 08/16/2014] [Accepted: 08/28/2014] [Indexed: 11/16/2022]
Abstract
Some Culicoides species of biting midges (Diptera: Ceratopogonidae) are biological virus vectors worldwide and have indeed been associated with outbreaks of important epizoonoses in recent years, such as bluetongue and Schmallenberg disease in northern Europe. These diseases, which affect domestic and wild ruminants, have caused considerable economic losses. Knowledge of substrates suitable for Culicoides larval development is important, particularly for the main vector temperate species. This study, realized during two years, aimed to highlight the larval development sites of these biting midge species in the immediate surroundings of ten Belgian cattle farms. Moreover, spatial distribution of the coprophilic Culicoides larvae (C. chiopterus and C. dewulfi) within pastures was studied with increasing distance from farms along linear transects (farm-pasture-woodland). A total of 4347 adult specimens belonging to 13 Culicoides species were obtained by incubation of 2131 soil samples belonging to 102 different substrates; 18 of these substrates were suitable for larval development. The Obsoletus complex (formed by two species) was observed in a wide range of substrates, including silage residues, components of a chicken coop, dung adhering to walls inside stables, leftover feed along the feed bunk, a compost pile of sugar beet residues, soil of a livestock trampling area, and decaying wood, while the following served as substrates for the other specimens: C. chiopterus, mainly cow dung; C. dewulfi, cow dung and molehill soil; C. circumscriptus, algae; C. festivipennis, algae and soil in stagnant water; C. nubeculosus, algae and silt specifically from the edge of a pond; C. punctatus, mainly wet soil between silage reserves; C. salinarius, algae; and C. stigma, algae and wet soil between silage reserves. We also recorded significantly higher densities of coprophilic larvae within pastures in cow dung located near forests, which is likely due to the localization of potential hosts; the presence of these larvae within cow dung is, however, uninfluenced by relative distance from farms. A better knowledge of the microhabitats of Culicoides biting midges and their spatial distribution may allow the development of targeted species-specific vector control strategies, and may help to prevent the creation of new larval development sites.
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Affiliation(s)
- Jean-Yves Zimmer
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liege, Passage des Déportés 2, B-5030 Gembloux, Belgium.
| | - Yves Brostaux
- Applied Statistics, Computer Science and Mathematics, Gembloux Agro-Bio Tech, University of Liege, Passage des Déportés 2, B-5030 Gembloux, Belgium
| | - Eric Haubruge
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liege, Passage des Déportés 2, B-5030 Gembloux, Belgium
| | - Frédéric Francis
- Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, University of Liege, Passage des Déportés 2, B-5030 Gembloux, Belgium
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Kelso JK, Milne GJ. A spatial simulation model for the dispersal of the bluetongue vector Culicoides brevitarsis in Australia. PLoS One 2014; 9:e104646. [PMID: 25105418 PMCID: PMC4126746 DOI: 10.1371/journal.pone.0104646] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 07/15/2014] [Indexed: 11/18/2022] Open
Abstract
Background The spread of Bluetongue virus (BTV) among ruminants is caused by movement of infected host animals or by movement of infected Culicoides midges, the vector of BTV. Biologically plausible models of Culicoides dispersal are necessary for predicting the spread of BTV and are important for planning control and eradication strategies. Methods A spatially-explicit simulation model which captures the two underlying population mechanisms, population dynamics and movement, was developed using extensive data from a trapping program for C. brevitarsis on the east coast of Australia. A realistic midge flight sub-model was developed and the annual incursion and population establishment of C. brevitarsis was simulated. Data from the literature was used to parameterise the model. Results The model was shown to reproduce the spread of C. brevitarsis southwards along the east Australian coastline in spring, from an endemic population to the north. Such incursions were shown to be reliant on wind-dispersal; Culicoides midge active flight on its own was not capable of achieving known rates of southern spread, nor was re-emergence of southern populations due to overwintering larvae. Data from midge trapping programmes were used to qualitatively validate the resulting simulation model. Conclusions The model described in this paper is intended to form the vector component of an extended model that will also include BTV transmission. A model of midge movement and population dynamics has been developed in sufficient detail such that the extended model may be used to evaluate the timing and extent of BTV outbreaks. This extended model could then be used as a platform for addressing the effectiveness of spatially targeted vaccination strategies or animal movement bans as BTV spread mitigation measures, or the impact of climate change on the risk and extent of outbreaks. These questions involving incursive Culicoides spread cannot be simply addressed with non-spatial models.
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Affiliation(s)
- Joel K. Kelso
- School of Computer Science and Software Engineering, University of Western Australia, Crawley, Western Australia, Australia
| | - George J. Milne
- School of Computer Science and Software Engineering, University of Western Australia, Crawley, Western Australia, Australia
- * E-mail:
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Carvalho LPC, Silva FS. Seasonal abundance of livestock-associated Culicoides species in northeastern Brazil. Med Vet Entomol 2014; 28:228-231. [PMID: 24382216 DOI: 10.1111/mve.12043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Revised: 05/14/2013] [Accepted: 05/22/2013] [Indexed: 06/03/2023]
Abstract
Culicoides biting midges (Diptera: Ceratopogonidae) are of great medical and veterinary importance because the haematophagous females of some species can transmit diseases to humans and animals. In order to determine the presence and seasonal abundance of the bluetongue virus (BTV) vector Culicoides insignis Lutz at domestic animal sheds in northeastern Brazil, insects were collected once a month between January and December 2010. Light traps were set from 18.00 to 06.00 hours at a pigsty, chicken coop and bovine corral. Culicoides insignis accounted for 81% of the 22,316 specimens collected. Other well-represented species were: Culicoides paucienfuscatus Barbosa (3246 individuals), Culicoides diabolicus Hoffman (308), Culicoides leopoldoi Ortiz (224) and Culicoides duartei Tavares and Luna Dias (221). The remainder accounted for 4% of the total sample. Culicoides insignis occurred mostly at the cattle corral, 98.2% in the rainy season. This study confirms the presence and close association of C. insignis with cattle in Maranhão state, northeastern Brazil and emphasizes the risk of bluetongue infections spreading in the area.
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Affiliation(s)
- L P C Carvalho
- Laboratory of Medical Entomology, Center for Agrarian and Environmental Sciences, Federal University of Maranhão, Chapadinha, Maranhão, Brazil
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Scolamacchia F, VAN DEN Broek J, Meiswinkel R, Heesterbeek JAP, Elbers ARW. Principal climatic and edaphic determinants of Culicoides biting midge abundance during the 2007-2008 bluetongue epidemic in the Netherlands, based on OVI light trap data. Med Vet Entomol 2014; 28:143-156. [PMID: 24148154 DOI: 10.1111/mve.12028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 05/07/2013] [Accepted: 05/14/2013] [Indexed: 06/02/2023]
Abstract
Palaearctic Culicoides midges (Diptera: Ceratopogonidae) represent a vital link in the northward advance of certain arboviral pathogens of livestock such as that caused by bluetongue virus. The effects of relevant ecological factors on weekly Culicoides vector abundances during the bluetongue virus serotype 8 epidemics in the Netherlands in 2007 and 2008 were quantified within a hurdle modelling framework. The relative role of meteorological parameters showed a broadly consistent association across species, with larger catches linked to temperature-related variables and lower wind speed. Moreover, vector abundance was found to be influenced by edaphic factors, likely related to species-specific breeding habitat preferences that differed markedly amongst some species. This is the first study on Culicoides vector species in the Netherlands identified during an entomological surveillance programme, in which an attempt is made to pinpoint the factors that influence midge abundance levels. In addition to providing key inputs into risk-mitigating tools for midge-borne pathogens and disease transmission models, the adoption of methods that explicitly address certain features of abundance datasets (frequent zero-count observations and over-dispersion) helped enhance the robustness of the ecological analysis.
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Affiliation(s)
- F Scolamacchia
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands; Department of Epidemiology, Crisis Organization and Diagnostics, Central Veterinary Institute of Wageningen University, Lelystad, the Netherlands
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Nicholas AH, McCorkell B. Evaluation of Metarhizium anisopliae for the control of Culicoides brevitarsis Kieffer (Diptera: Ceratopogonidae), the principal vector of bluetongue virus in Australia. J Vector Ecol 2014; 39:213-218. [PMID: 24820575 DOI: 10.1111/j.1948-7134.2014.12089.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 03/11/2014] [Indexed: 06/03/2023]
Abstract
Four isolates of the entomopathogenic fungus Metarhizium anisopliae were tested for their potential to control the biting midge Culicoides brevitarsis, the principal vector of bluetongue virus in Australia. Adult C. brevitarsis died three to eight days after walking on paper substrate treated with 0.7 g/m(2) conidia of any of the isolates, indicating that M. anisopliae has potential as a surface treatment or topical application control strategy. Incorporation of the fungus into freshly excreted cattle dung at rates of between 0.25 and 1 g conidia/kg reduced the emergence of adult midges by up to 98.5% compared to untreated dung indicating that M. anisopliae has the potential to control C. brevitarsis larvae in cattle dung. Three of the isolates produced similar mortality rates on adult and immature C. brevitarsis while the fourth isolate produced lower, but still significant, mortality rates on adult and immature stages.
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Affiliation(s)
- A H Nicholas
- New South Wales Department of Primary Industries, Central Coast Primary Industries Centre, Locked Bag 26, Gosford, NSW 2250, Australia.
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Batten C, Darpel K, Henstock M, Fay P, Veronesi E, Gubbins S, Graves S, Frost L, Oura C. Evidence for transmission of bluetongue virus serotype 26 through direct contact. PLoS One 2014; 9:e96049. [PMID: 24797910 PMCID: PMC4010411 DOI: 10.1371/journal.pone.0096049] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 04/03/2014] [Indexed: 01/02/2023] Open
Abstract
The aim of this study was to assess the mechanisms of transmission of bluetongue virus serotype 26 (BTV-26) in goats. A previous study, which investigated the pathogenicity and infection kinetics of BTV-26 in goats, unexpectedly revealed that one control goat may have been infected through a direct contact transmission route. To investigate the transmission mechanisms of BTV-26 in more detail an experimental infection study was carried out in which three goats were infected with BTV-26, three goats were kept uninfected, but were housed in direct contact with the infected goats, and an additional four goats were kept in indirect contact separated from infected goats by metal gates. This barrier allowed the goats to have occasional face-to-face contact in the same airspace, but feeding, watering, sampling and environmental cleaning was carried out separately. The three experimentally infected goats did not show clinical signs of BTV, however high levels of viral RNA were detected and virus was isolated from their blood. At 21 dpi viral RNA was detected in, and virus was isolated from the blood of the three direct contact goats, which also seroconverted. The four indirect barrier contact goats remained uninfected throughout the duration of the experiment. In order to assess replication in a laboratory model species of Culicoides biting midge, more than 300 Culicoides sonorensis were fed a BTV-26 spiked blood meal and incubated for 7 days. The dissemination of BTV-26 in individual C. sonorensis was inferred from the quantity of virus RNA and indicated that none of the insects processed at day 7 possessed transmissible infections. This study shows that BTV-26 is easily transmitted through direct contact transmission between goats, and the strain does not seem to replicate in C. sonorensis midges using standard incubation conditions.
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Affiliation(s)
- Carrie Batten
- Non Vesicular Reference Laboratory, The Pirbright Institute, Woking, Surrey, United Kingdom
| | - Karin Darpel
- Vaccinology, The Pirbright Institute, Woking, Surrey, United Kingdom
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Mark Henstock
- Non Vesicular Reference Laboratory, The Pirbright Institute, Woking, Surrey, United Kingdom
| | - Petra Fay
- Non Vesicular Reference Laboratory, The Pirbright Institute, Woking, Surrey, United Kingdom
| | - Eva Veronesi
- Entomology, The Pirbright Institute, Woking, Surrey, United Kingdom
| | - Simon Gubbins
- Centre for Integrative Biology, The Pirbright Institute, Woking, Surrey, United Kingdom
| | - Samantha Graves
- Non Vesicular Reference Laboratory, The Pirbright Institute, Woking, Surrey, United Kingdom
| | - Lorraine Frost
- Non Vesicular Reference Laboratory, The Pirbright Institute, Woking, Surrey, United Kingdom
| | - Christopher Oura
- Non Vesicular Reference Laboratory, The Pirbright Institute, Woking, Surrey, United Kingdom
- School of Veterinary Medicine, University of the West Indies, St. Augustine, Trinidad and Tobago
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Van Houten D. [The effect of vaccination of ewes on transplacental transmission of the bluetongue virus]. Tijdschr Diergeneeskd 2014; 139:38-39. [PMID: 24844091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Van Bodegraven REM, Berends BR, Burt SA. [Vector-borne diseases in ruminants in the Netherlands]. Tijdschr Diergeneeskd 2014; 139:34-39. [PMID: 24498688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- Rebecca E M Van Bodegraven
- Institute for Risk Assessment Sciences, Divisie Veterinaire Volksgezondheid, Faculteit Diergeneeskunde, Universiteit Utrecht, Postbus 80175, 3508 TD Utrecht
| | - Boyd R Berends
- Institute for Risk Assessment Sciences, Divisie Veterinaire Volksgezondheid, Faculteit Diergeneeskunde, Universiteit Utrecht, Postbus 80175, 3508 TD Utrecht
| | - Sara A Burt
- Institute for Risk Assessment Sciences, Divisie Veterinaire Volksgezondheid, Faculteit Diergeneeskunde, Universiteit Utrecht, Postbus 80175, 3508 TD Utrecht
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Ducheyne E, Miranda Chueca MA, Lucientes J, Calvete C, Estrada R, Boender GJ, Goossens E, De Clercq EM, Hendrickx G. Abundance modelling of invasive and indigenous Culicoides species in Spain. Geospat Health 2013; 8:241-254. [PMID: 24258899 DOI: 10.4081/gh.2013.70] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this paper we present a novel methodology applied in Spain to model spatial abundance patterns of potential vectors of disease at a medium spatial resolution of 5 x 5 km using a countrywide database with abundance data for five Culicoides species, random regression Forest modelling and a spatial dataset of ground measured and remotely sensed eco-climatic and environmental predictor variables. First the probability of occurrence was computed. In a second step a direct regression between the probability of occurrence and trap abundance was established to verify the linearity of the relationship. Finally the probability of occurrence was used in combination with the set of predictor variables to model abundance. In each case the variable importance of the predictors was used to biologically interpret results and to compare both model outputs, and model performance was assessed using four different accuracy measures. Results are shown for C. imicola, C. newsteadii, C. pulicaris group, C. punctatus and C. obsoletus group. In each case the probability of occurrence is a good predictor of abundance at the used spatial resolution of 5 x 5 km. In addition, the C. imicola and C. obsoletus group are highly driven by summer rainfall. The spatial pattern is inverse between the two species, indicating that the lower and upper thresholds are different. C. pulicaris group is mainly driven by temperature. The patterns for C. newsteadii and C. punctatus are less clear. It is concluded that the proposed methodology can be used as an input to transmission-infection-recovery (TIR) models and R0 models. The methodology will become available to the general public as part of the VECMAP™ software.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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] [What about the content of this article? (0)] [Affiliation(s)] [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, Bødker R, Stockmarr A, Lind P, Heegaard PMH. Quantifying dispersal of european culicoides (Diptera: Ceratopogonidae) vectors between farms using a novel mark-release-recapture technique. PLoS One 2013; 8:e61269. [PMID: 23630582 PMCID: PMC3632603 DOI: 10.1371/journal.pone.0061269] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 03/07/2013] [Indexed: 11/18/2022] Open
Abstract
Studying the dispersal of small flying insects such as Culicoides constitutes a great challenge due to huge population sizes and lack of a method to efficiently mark and objectively detect many specimens at a time. We here describe a novel mark-release-recapture method for Culicoides in the field using fluorescein isothiocyanate (FITC) as marking agent without anaesthesia. Using a plate scanner, this detection technique can be used to analyse thousands of individual Culicoides specimens per day at a reasonable cost. We marked and released an estimated 853 specimens of the Pulicaris group and 607 specimens of the Obsoletus group on a cattle farm in Denmark. An estimated 9,090 (8,918-9,260) Obsoletus group specimens and 14,272 (14,194-14,448) Pulicaris group specimens were captured in the surroundings and subsequently analysed. Two (0.3%) Obsoletus group specimens and 28 (4.6%) Pulicaris group specimens were recaptured. The two recaptured Obsoletus group specimens were caught at the release point on the night following release. Eight (29%) of the recaptured Pulicaris group specimens were caught at a pig farm 1,750 m upwind from the release point. Five of these were recaptured on the night following release and the three other were recaptured on the second night after release. This is the first time that movement of Culicoides vectors between farms in Europe has been directly quantified. The findings suggest an extensive and rapid exchange of disease vectors between farms. Rapid movement of vectors between neighboring farms may explain the the high rate of spatial spread of Schmallenberg and bluetongue virus (BTV) in northern Europe.
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Affiliation(s)
- Carsten Kirkeby
- Section of Epidemiology, National Veterinary Institute, Technical University of Denmark, Frederiksberg C, Denmark.
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Brugger K, Rubel F. Bluetongue disease risk assessment based on observed and projected Culicoides obsoletus spp. vector densities. PLoS One 2013; 8:e60330. [PMID: 23560090 PMCID: PMC3613389 DOI: 10.1371/journal.pone.0060330] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 02/25/2013] [Indexed: 11/29/2022] Open
Abstract
Bluetongue is an arboviral disease of ruminants causing significant economic losses. Our risk assessment is based on the epidemiological key parameter, the basic reproduction number. It is defined as the number of secondary cases caused by one primary case in a fully susceptible host population, in which values greater than one indicate the possibility, i.e., the risk, for a major disease outbreak. In the course of the Bluetongue virus serotype 8 (BTV-8) outbreak in Europe in 2006 we developed such a risk assessment for the University of Veterinary Medicine Vienna, Austria. Basic reproduction numbers were calculated using a well-known formula for vector-borne diseases considering the population densities of hosts (cattle and small ruminants) and vectors (biting midges of the Culicoides obsoletus spp.) as well as temperature dependent rates. The latter comprise the biting and mortality rate of midges as well as the reciprocal of the extrinsic incubation period. Most important, but generally unknown, is the spatio-temporal distribution of the vector density. Therefore, we established a continuously operating daily monitoring to quantify the seasonal cycle of the vector population by a statistical model. We used cross-correlation maps and Poisson regression to describe vector densities by environmental temperature and precipitation. Our results comprise time series of observed and simulated Culicoides obsoletus spp. counts as well as basic reproduction numbers for the period 2009–2011. For a spatio-temporal risk assessment we projected our results from the location of Vienna to the entire region of Austria. We compiled both daily maps of vector densities and the basic reproduction numbers, respectively. Basic reproduction numbers above one were generally found between June and August except in the mountainous regions of the Alps. The highest values coincide with the locations of confirmed BTV cases.
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Affiliation(s)
- Katharina Brugger
- Institute for Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria.
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