1
|
Del Lesto I, Magliano A, Casini R, Ermenegildi A, Rombolà P, De Liberato C, Romiti F. Ecological niche modelling of Culicoides imicola and future range shifts under climate change scenarios in Italy. MEDICAL AND VETERINARY ENTOMOLOGY 2024. [PMID: 38783513 DOI: 10.1111/mve.12730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 05/09/2024] [Indexed: 05/25/2024]
Abstract
Culicoides imicola is the main vector of viral diseases of livestock in Europe such as bluetongue (BT), African horse sickness and epizootic haemorrhagic disease. Climatic factors are the main drivers of C. imicola occurrence and its distribution might be subject to rapid shifts due to climate change. Entomological data, collected during BT surveillance, and climatic/environmental variables were used to analyse ecological niche and to model C. imicola distribution and possible future range shifts in Italy. An ensemble technique was used to weigh the performance of machine learning, linear and profile methods. Updated future climate projections from the latest phase of the Climate Model Intercomparison Project were used to generate future distributions for the next three 20-year periods, according to combinations of general circulation models and shared socioeconomic pathways and considering different climate change scenarios. Results indicated the minimum temperature of the coldest month (BIO 6) and precipitation of the driest-warmest months (BIO 14) as the main limiting climatic factors. Indeed, BIO 6 and BIO 14 reported the two highest values of variable importance, respectively, 9.16% (confidence interval [CI] = 7.99%-10.32%), and 2.01% (CI = 1.57%-2.44%). Under the worst-case scenario of climate change, C. imicola range is expected to expand northward and shift away from the coasts of central Italy, while in some areas of southern Italy, environmental suitability will decrease. Our results provide predictions of C. imicola distribution according to the most up-to-date future climate projections and should be of great use to surveillance management at regional and national scales.
Collapse
Affiliation(s)
- Irene Del Lesto
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri', Pisa, Italy
| | - Adele Magliano
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri', Rome, Italy
| | - Riccardo Casini
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri', Rome, Italy
| | - Arianna Ermenegildi
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri', Rome, Italy
| | - Pasquale Rombolà
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri', Rome, Italy
| | - Claudio De Liberato
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri', Rome, Italy
| | - Federico Romiti
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana 'M. Aleandri', Rome, Italy
| |
Collapse
|
2
|
Carpenter M, Kopanke J, Lee J, Rodgers C, Reed K, Sherman TJ, Graham B, Cohnstaedt LW, Wilson WC, Stenglein M, Mayo C. Evaluating Temperature Effects on Bluetongue Virus Serotype 10 and 17 Coinfection in Culicoides sonorensis. Int J Mol Sci 2024; 25:3063. [PMID: 38474308 PMCID: PMC10932384 DOI: 10.3390/ijms25053063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 03/02/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
Bluetongue virus (BTV) is a segmented, double-stranded RNA virus transmitted by Culicoides midges that infects ruminants. As global temperatures increase and geographical ranges of midges expand, there is increased potential for BTV outbreaks from incursions of novel serotypes into endemic regions. However, an understanding of the effect of temperature on reassortment is lacking. The objectives of this study were to compare how temperature affected Culicoides survival, virogenesis, and reassortment in Culicoides sonorensis coinfected with two BTV serotypes. Midges were fed blood meals containing BTV-10, BTV-17, or BTV serotype 10 and 17 and maintained at 20 °C, 25 °C, or 30 °C. Midge survival was assessed, and pools of midges were collected every other day to evaluate virogenesis of BTV via qRT-PCR. Additional pools of coinfected midges were collected for BTV plaque isolation. The genotypes of plaques were determined using next-generation sequencing. Warmer temperatures impacted traits related to vector competence in offsetting ways: BTV replicated faster in midges at warmer temperatures, but midges did not survive as long. Overall, plaques with BTV-17 genotype dominated, but BTV-10 was detected in some plaques, suggesting parental strain fitness may play a role in reassortment outcomes. Temperature adds an important dimension to host-pathogen interactions with implications for transmission and evolution.
Collapse
Affiliation(s)
- Molly Carpenter
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Jennifer Kopanke
- Department of Comparative Medicine, Oregon Health & Science University, Portland, OR 97239, USA;
| | - Justin Lee
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Case Rodgers
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Kirsten Reed
- Wisconsin Veterinary Diagnostic Laboratory, University of Wisconsin-Madison, Madison, WI 53706, USA;
| | - Tyler J. Sherman
- Diagnostic Medicine Center, Colorado State University, 2450 Gillette Drive, Fort Collins, CO 80526, USA;
| | - Barbara Graham
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Lee W. Cohnstaedt
- Foreign Arthropod-Borne Animal Diseases Research Unit, The National Bio and Agro-Defense Facility, USDA Agricultural Research Service, P.O. Box 1807, Manhattan, KS 66505, USA; (L.W.C.); (W.C.W.)
| | - William C. Wilson
- Foreign Arthropod-Borne Animal Diseases Research Unit, The National Bio and Agro-Defense Facility, USDA Agricultural Research Service, P.O. Box 1807, Manhattan, KS 66505, USA; (L.W.C.); (W.C.W.)
| | - Mark Stenglein
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| | - Christie Mayo
- Department of Microbiology, Immunology and Pathology, Colorado State University, 1601 Campus Delivery, Fort Collins, CO 80526, USA; (M.C.); (J.L.); (C.R.); (B.G.); (M.S.)
| |
Collapse
|
3
|
Caixeta EA, Pinheiro MA, Lucchesi VS, Oliveira AGG, Galinari GCF, Tinoco HP, Coelho CM, Lobato ZIP. The Study of Bluetongue Virus (BTV) and Epizootic Hemorrhagic Disease Virus (EHDV) Circulation and Vectors at the Municipal Parks and Zoobotanical Foundation of Belo Horizonte, Minas Gerais, Brazil (FPMZB-BH). Viruses 2024; 16:293. [PMID: 38400068 PMCID: PMC10892844 DOI: 10.3390/v16020293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 02/25/2024] Open
Abstract
Bluetongue Virus (BTV) and Epizootic Hemorrhagic Disease Virus (EHDV) are Orbiviruses primarily transmitted by their biological vector, Culicoides spp. Latreille, 1809 (Diptera: Ceratopogonidae). These viruses can infect a diverse range of vertebrate hosts, leading to disease outbreaks in domestic and wild ruminants worldwide. This study, conducted at the Belo Horizonte Municipal Parks and Zoobotany Foundation (FPMZB-BH), Minas Gerais, Brazil, focused on Orbivirus and its vectors. Collections of Culicoides spp. were carried out at the FPMZB-BH from 9 December 2021 to 18 November 2022. A higher prevalence of these insects was observed during the summer months, especially in February. Factors such as elevated temperatures, high humidity, fecal accumulation, and proximity to large animals, like camels and elephants, were associated with increased Culicoides capture. Among the identified Culicoides spp. species, Culicoides insignis Lutz, 1913, constituted 75%, and Culicoides pusillus Lutz, 1913, 6% of the collected midges, both described as competent vectors for Orbivirus transmission. Additionally, a previously unreported species in Minas Gerais, Culicoides debilipalpis Lutz, 1913, was identified, also suspected of being a transmitter of these Orbiviruses. The feeding preferences of some Culicoides species were analyzed, revealing that C. insignis feeds on deer, Red deer (Cervus elaphus) and European fallow deer (Dama dama). Different Culicoides spp. were also identified feeding on humans, raising concerns about the potential transmission of arboviruses at the site. In parallel, 72 serum samples from 14 susceptible species, including various Cervids, collected between 2012 and 2022 from the FPMZB-BH serum bank, underwent Agar Gel Immunodiffusion (AGID) testing for BTV and EHDV. The results showed 75% seropositivity for BTV and 19% for EHDV. Post-testing analysis revealed variations in antibody presence against BTV in a tapir and a fallow deer and against EHDV in a gemsbok across different years. These studies confirm the presence of BTV and EHDV vectors, along with potential virus circulation in the zoo. Consequently, implementing control measures is essential to prevent susceptible species from becoming infected and developing clinical diseases.
Collapse
Affiliation(s)
- Eduardo Alves Caixeta
- Department of Preventive Veterinary Medicine (DMVP), Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte 31270-901, Minas Gerais, Brazil; (E.A.C.); (M.A.P.); (V.S.L.); (A.G.G.O.); (G.C.F.G.)
| | - Mariana Andrioli Pinheiro
- Department of Preventive Veterinary Medicine (DMVP), Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte 31270-901, Minas Gerais, Brazil; (E.A.C.); (M.A.P.); (V.S.L.); (A.G.G.O.); (G.C.F.G.)
| | - Victoria Souza Lucchesi
- Department of Preventive Veterinary Medicine (DMVP), Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte 31270-901, Minas Gerais, Brazil; (E.A.C.); (M.A.P.); (V.S.L.); (A.G.G.O.); (G.C.F.G.)
| | - Anna Gabriella Guimarães Oliveira
- Department of Preventive Veterinary Medicine (DMVP), Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte 31270-901, Minas Gerais, Brazil; (E.A.C.); (M.A.P.); (V.S.L.); (A.G.G.O.); (G.C.F.G.)
| | - Grazielle Cossenzo Florentino Galinari
- Department of Preventive Veterinary Medicine (DMVP), Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte 31270-901, Minas Gerais, Brazil; (E.A.C.); (M.A.P.); (V.S.L.); (A.G.G.O.); (G.C.F.G.)
| | - Herlandes Penha Tinoco
- Belo Horizonte Municipal Parks and Zoobotany Foundation (FPMZB-BH), Belo Horizonte 31365-450, Minas Gerais, Brazil; (H.P.T.); (C.M.C.)
| | - Carlyle Mendes Coelho
- Belo Horizonte Municipal Parks and Zoobotany Foundation (FPMZB-BH), Belo Horizonte 31365-450, Minas Gerais, Brazil; (H.P.T.); (C.M.C.)
| | - Zélia Inês Portela Lobato
- Department of Preventive Veterinary Medicine (DMVP), Veterinary School, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte 31270-901, Minas Gerais, Brazil; (E.A.C.); (M.A.P.); (V.S.L.); (A.G.G.O.); (G.C.F.G.)
| |
Collapse
|
4
|
Navarro Mamani DA, Ramos Huere H, Vera Buendia R, Rojas M, Chunga WA, Valdez Gutierrez E, Vergara Abarca W, Rivera Gerónimo H, Altamiranda-Saavedra M. Would Climate Change Influence the Potential Distribution and Ecological Niche of Bluetongue Virus and Its Main Vector in Peru? Viruses 2023; 15:v15040892. [PMID: 37112872 PMCID: PMC10145190 DOI: 10.3390/v15040892] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 03/26/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023] Open
Abstract
Bluetongue virus (BTV) is an arbovirus that is transmitted between domestic and wild ruminants by Culicoides spp. Its worldwide distribution depends on competent vectors and suitable environmental ecosystems that are becoming affected by climate change. Therefore, we evaluated whether climate change would influence the potential distribution and ecological niche of BTV and Culicoides insignis in Peru. Here, we analyzed BTV (n = 145) and C. insignis (n = 22) occurrence records under two shared socioeconomic pathway scenarios (SSP126 and SSP585) with five primary general circulation models (GCMs) using the kuenm R package v.1.1.9. Then, we obtained binary presence–absence maps and represented the risk of transmission of BTV and niche overlapping. The niche model approach showed that north and east Peru presented suitability in the current climate scenario and they would have a decreased risk of BTV, whilst its vector would be stable and expand with high agreement for the five GCMs. In addition, its niche overlap showed that the two niches almost overlap at present and would completely overlap with one another in future climate scenarios. These findings might be used to determine the areas of highest priority for entomological and virological investigations and surveillance in order to control and prevent bluetongue infections in Peru.
Collapse
Affiliation(s)
- Dennis A. Navarro Mamani
- Laboratorio de Microbiología y Parasitología—Sección Virología, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima 15001, Peru
- Correspondence:
| | - Heydi Ramos Huere
- Laboratorio de Microbiología y Parasitología—Sección Virología, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima 15001, Peru
| | - Renzo Vera Buendia
- Laboratorio de Microbiología y Parasitología—Sección Virología, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima 15001, Peru
| | - Miguel Rojas
- Laboratorio de Inmunología, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima 15001, Peru
| | - Wilfredo Arque Chunga
- Laboratorio de Referencia Nacional de Metaxenicas y Zoonosis Bacterianas, Centro Nacional de Salud Pública, Instituto Nacional de Salud, Lima 15001, Peru
| | - Edgar Valdez Gutierrez
- Laboratorio de Sanidad Animal “M.V. Atilio Pacheco Pacheco”, Escuela Profesional de Zootecnia, Universidad Nacional San Antonio Abad del Cusco, Cusco 08681, Peru
| | - Walter Vergara Abarca
- Laboratorio de Sanidad Animal “M.V. Atilio Pacheco Pacheco”, Escuela Profesional de Zootecnia, Universidad Nacional San Antonio Abad del Cusco, Cusco 08681, Peru
| | - Hermelinda Rivera Gerónimo
- Laboratorio de Microbiología y Parasitología—Sección Virología, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima 15001, Peru
| | - Mariano Altamiranda-Saavedra
- Grupo de Investigación Bioforense, Tecnológico de Antioquia Institución Universitaria, Medellín 050005, Colombia
| |
Collapse
|
5
|
Fetene E, Teka G, Dejene H, Mandefro D, Teshome T, Temesgen D, Negussie H, Mulatu T, Jaleta MB, Leta S. Modeling the spatial distribution of Culicoides species (Diptera: Ceratopogonidae) as vectors of animal diseases in Ethiopia. Sci Rep 2022; 12:12904. [PMID: 35902616 PMCID: PMC9334590 DOI: 10.1038/s41598-022-16911-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 07/18/2022] [Indexed: 11/24/2022] Open
Abstract
Culicoides biting midges (Diptera: Ceratopogonidae) are the major vectors of bluetongue, Schmallenberg, and African horse sickness viruses. This study was conducted to survey Culicoides species in different parts of Ethiopia and to develop habitat suitability for the major Culicoides species in Ethiopia. Culicoides traps were set in different parts of the country from December 2018 to April 2021 using UV light Onderstepoort traps and the collected Culicoides were sorted to species level. To develop the species distribution model for the two predominant Culicoides species, namely Culicoides imicola and C. kingi, an ensemble modeling technique was used with the Biomod2 package of R software. KAPPA True skill statistics (TSS) and ROC curve were used to evaluate the accuracy of species distribution models. In the ensemble modeling, models which score TSS values greater than 0.8 were considered. Negative binomialregression models were used to evaluate the relationship between C. imicola and C. kingi catch and various environmental and climatic factors. During the study period, a total of 9148 Culicoides were collected from 66 trapping sites. Of the total 9148, 8576 of them belongs to seven species and the remaining 572 Culicoides were unidentified. The predominant species was C. imicola (52.8%), followed by C. kingi (23.6%). The abundance of these two species was highly influenced by the agro-ecological zone of the capture sites and the proximity of the capture sites to livestock farms. Climatic variables such as mean annual minimum and maximum temperature and mean annual rainfall were found to influence the catch of C. imicola at the different study sites. The ensemble model performed very well for both species with KAPPA (0.9), TSS (0.98), and ROC (0.999) for C. imicola and KAPPA (0.889), TSS (0.999), and ROC (0.999) for C. kingi. Culicoides imicola has a larger suitability range compared to C. kingi. The Great Rift Valley in Ethiopia, the southern and eastern parts of the country, and the areas along the Blue Nile and Lake Tana basins in northern Ethiopia were particularly suitable for C. imicola. High suitability for C. kingi was found in central Ethiopia and the Southern Nations, Nationalities and Peoples Region (SNNPR). The habitat suitability model developed here could help researchers better understand where the above vector-borne diseases are likely to occur and target surveillance to high-risk areas.
Collapse
Affiliation(s)
- Eyerusalem Fetene
- College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box 34, Bishoftu, Ethiopia
| | - Getachew Teka
- College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box 34, Bishoftu, Ethiopia
| | - Hana Dejene
- College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box 34, Bishoftu, Ethiopia.,Faculty of Agriculture and Veterinary Science, Ambo University, P.O. Box 19, Ambo, Ethiopia
| | - Deresegn Mandefro
- College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box 34, Bishoftu, Ethiopia
| | - Tsedale Teshome
- College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box 34, Bishoftu, Ethiopia
| | - Dawit Temesgen
- College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box 34, Bishoftu, Ethiopia
| | - Haileleul Negussie
- College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box 34, Bishoftu, Ethiopia
| | - Tesfaye Mulatu
- National Animal Health Diagnostic and Investigation Centre (NAHDIC), P. O. Box 4, Sebeta, Ethiopia
| | - Megarsa Bedasa Jaleta
- College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box 34, Bishoftu, Ethiopia
| | - Samson Leta
- College of Veterinary Medicine and Agriculture, Addis Ababa University, P. O. Box 34, Bishoftu, Ethiopia.
| |
Collapse
|
6
|
Stokes JE, Carpenter S, Sanders C, Gubbins S. Emergence dynamics of adult Culicoides biting midges at two farms in south-east England. Parasit Vectors 2022; 15:251. [PMID: 35820957 PMCID: PMC9277857 DOI: 10.1186/s13071-022-05370-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/01/2022] [Indexed: 11/24/2022] Open
Abstract
Background Culicoides biting midges (Diptera: Ceratopogonidae) are biological vectors of livestock arboviruses that cause diseases with significant economic, social and welfare impacts. Within temperate regions, livestock movement during arbovirus outbreaks can be facilitated by declaring a ‘seasonal vector-free period’ (SVFP) during winter when adult Culicoides are not active. In this study we carry out long-term monitoring of Culicoides adult emergence from larval development habitats at two farms in the UK to validate current definitions of the SVFP and to provide novel bionomic data for known vector species. Methods Standard emergence traps were used to collect emerging adult Culicoides from dung heaps at two cattle farms in the south-east of England from June to November 2016 and March 2017 to May 2018. Culicoides were morphologically identified to species or complex level and count data were analysed using a simple population dynamic model for pre-adult Culicoides that included meteorological components. Results More than 96,000 Culicoides were identified from 267 emergence trapping events across 2 years, revealing clear evidence of bivoltinism from peaks of male populations of Culicoidesobsoletus emerging from dung heaps. This pattern was also reflected in the emergence of adult female Obsoletus complex populations, which dominated the collections (64.4% of total catch) and emerged throughout the adult active period. Adult male C. obsoletus were observed emerging earlier than females (protandry) and emergence of both sexes occurred throughout the year. Culicoides chiopterus and Culicoides scoticus were also identified in spring emergence collections, providing the first evidence for the overwintering of larvae in dung heaps for these species. Conclusions This study demonstrates continual and highly variable rates of emergence of Culicoides throughout the year. A lack of evidence for mass emergence in spring along with the ability to observe male generations highlights the need for complementary surveillance techniques in addition to light-trap data when investigating seasonality and phenology. Evidence was found of other vector species, C. chiopterus and C. scoticus, utilising cattle dung heaps as an overwintering habitat, further highlighting the importance of these habitats on farms. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05370-z.
Collapse
Affiliation(s)
- Jessica Eleanor Stokes
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK. .,ProScience Ltd, Gloucestershire, GL11 5SD, UK.
| | - Simon Carpenter
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK
| | | | - Simon Gubbins
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK
| |
Collapse
|
7
|
Effect of Constant Temperatures on Culicoides sonorensis Midge Physiology and Vesicular Stomatitis Virus Infection. INSECTS 2022; 13:insects13040372. [PMID: 35447814 PMCID: PMC9024736 DOI: 10.3390/insects13040372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/01/2022] [Accepted: 04/07/2022] [Indexed: 02/04/2023]
Abstract
Simple Summary Culicoides biting midges are nuisance pests of livestock and well-known vectors of veterinary arboviruses, such as vesicular stomatitis virus (VSV). Female midges ingest viruses when feeding on blood to obtain protein for egg-laying. After ingesting a VSV-infected blood meal, the environmental temperature of the resting location mediates the rates at which blood is digested, eggs are laid, and virus particles are replicated inside the midge. VSV transmission will occur if the timing of virus amplification aligns with the next feeding–egg-laying cycle. We evaluated the impact of constant environmental temperatures on midge physiology (lifespan and reproduction), vector competence for VSV (infection and dissemination), and thermal resting preference. Our results indicate that after ingesting a blood meal, most midges prefer to rest in areas that fall within their preferred physiological range regardless of the temperatures at which they were being maintained. These preferred temperatures maximized their survival, the number of egg-laying cycles, and the likelihood of VSV transmission. Our temperature approach shows that in the Culicoides–VSV system, the preferred resting temperature selected by blood-fed midges is beneficial for both insect and virus transmission. Abstract Culicoides midges play an important role in vesicular stomatitis virus (VSV) transmission to US livestock. After VSV-blood feeding, blood digestion followed by oviposition occurs while ingested virus particles replicate and disseminate to salivary glands for transmission during subsequent blood-feeding events. Changes to environmental temperature may alter the feeding–oviposition–refeeding cycles, midge survival, VSV infection, and overall vector capacity. However, the heterothermic midge may respond rapidly to environmental changes by adjusting their thermal behavior to resting in areas closer to their physiological range. Here we investigated the effects of four constant environmental temperatures (20, 25, 30, and 35 °C) on C. sonorensis survival, oviposition, and VSV infection, as well as resting thermal preferences after blood-feeding. We found that most midges preferred to rest in areas at 25–30 °C. These two constant temperatures (25 and 30 °C) allowed an intermediate fitness performance, with a 66% survival probability by day 10 and oviposition cycles occurring every 2–3 days. Additionally, VSV infection rates in bodies and heads with salivary glands were higher than in midges held at 20 °C and 35 °C. Our results provide insight into the implications of temperature on VSV–Culicoides interactions and confirm that the range of temperature preferred by midges can benefit both the vector and the arbovirus.
Collapse
|
8
|
The Absence of Abdominal Pigmentation in Livestock Associated Culicoides following Artificial Blood Feeding and the Epidemiological Implication for Arbovirus Surveillance. Pathogens 2021; 10:pathogens10121571. [PMID: 34959526 PMCID: PMC8705276 DOI: 10.3390/pathogens10121571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 12/02/2022] Open
Abstract
Culicoides midges (Diptera: Ceratopogonidae), the vectors of economically important arboviruses such as bluetongue virus and African horse sickness virus, are of global importance. In the absence of transovarial transmission, the parity rate of a Culicoides population provides imperative information regarding the risk of virus dispersal. Abdominal pigmentation, which develops after blood feeding and ovipositioning, is used as an indicator of parity in Culicoides. During oral susceptibility trials over the last three decades, a persistent proportion of blood engorged females did not develop pigment after incubation. The present study, combining a number of feeding trials and different artificial feeding methods, reports on this phenomenon, as observed in various South African and Italian Culicoides species and populations. The absence of pigmentation in artificial blood-fed females was found in at least 23 Culicoides species, including important vectors such as C. imicola, C. bolitinos, C. obsoletus, and C. scoticus. Viruses were repeatedly detected in these unpigmented females after incubation. Blood meal size seems to play a role and this phenomenon could be present in the field and requires consideration, especially regarding the detection of virus in apparent “nulliparous” females and the identification of overwintering mechanisms and seasonally free vector zones.
Collapse
|
9
|
Erram D, Vincent Black T, Burkett-Cadena N. Host Bloodmeal Source Has No Significant Effect on the Fecundity and Subsequent Larval Development Traits of the Progeny in Culicoides furens Poey (Diptera: Ceratopogonidae). JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:2439-2445. [PMID: 33999171 DOI: 10.1093/jme/tjab085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Indexed: 06/12/2023]
Abstract
Culicoides Latreille species (Diptera: Ceratopogonidae) are insects of significant medical and veterinary importance worldwide because their bites can cause major annoyance, allergic reactions, and/or pathogen transmission to vertebrates, including humans. In this study, we examined the effect of host bloodmeal source on the fecundity and subsequent larval development traits of the progeny of Culicoides furens Poey, a nuisance species in coastal Florida. Field-collected females were fed on two different classes of hosts: birds (chicken) or mammals (human). Fecundity outcomes of the females and larval developmental traits of the progeny were recorded and compared between the two groups. The percentage of females that developed eggs, percentage of gravid females that deposited eggs, number of eggs produced per female, number of eggs deposited per female, egg hatch rates, larval survival rates, time to pupation, pupal sex-ratios, and adult eclosion rates were not significantly different between the two groups. Our results demonstrate that the host bloodmeal source has no significant effect on the fecundity and subsequent larval developmental life-history traits of the progeny in C. furens. Previous studies reported C. furens to be a generalist feeder that shows no host preference for birds or mammals. Collectively, these findings suggest that C. furens is well adapted, not just behaviorally, but also physiologically to efficiently utilize blood meals from avian and mammalian hosts, a quality that offers a major evolutionary advantage to the success of this midge species as a generalist feeder.
Collapse
Affiliation(s)
- Dinesh Erram
- Florida Medical Entomology Laboratory, UF/IFAS, Vero Beach, FL, USA
| | | | | |
Collapse
|
10
|
Predicting the Geographic Range of an Invasive Livestock Disease across the Contiguous USA under Current and Future Climate Conditions. CLIMATE 2021. [DOI: 10.3390/cli9110159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Vesicular stomatitis (VS) is the most common vesicular livestock disease in North America. Transmitted by direct contact and by several biting insect species, this disease results in quarantines and animal movement restrictions in horses, cattle and swine. As changes in climate drive shifts in geographic distributions of vectors and the viruses they transmit, there is considerable need to improve understanding of relationships among environmental drivers and patterns of disease occurrence. Multidisciplinary approaches integrating pathology, ecology, climatology, and biogeophysics are increasingly relied upon to disentangle complex relationships governing disease. We used a big data model integration approach combined with machine learning to estimate the potential geographic range of VS across the continental United States (CONUS) under long-term mean climate conditions over the past 30 years. The current extent of VS is confined to the western portion of the US and is related to summer and winter precipitation, winter maximum temperature, elevation, fall vegetation biomass, horse density, and proximity to water. Comparison with a climate-only model illustrates the importance of current processes-based parameters and identifies regions where uncertainty is likely to be greatest if mechanistic processes change. We then forecast shifts in the range of VS using climate change projections selected from CMIP5 climate models that most realistically simulate seasonal temperature and precipitation. Climate change scenarios that altered climatic conditions resulted in greater changes to potential range of VS, generally had non-uniform impacts in core areas of the current potential range of VS and expanded the range north and east. We expect that the heterogeneous impacts of climate change across the CONUS will be exacerbated with additional changes in land use and land cover affecting biodiversity and hydrological cycles that are connected to the ecology of insect vectors involved in VS transmission.
Collapse
|
11
|
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] [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.
Collapse
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
| |
Collapse
|
12
|
Van den Eynde C, Sohier C, Matthijs S, De Regge N. Temperature and food sources influence subadult development and blood-feeding response of Culicoides obsoletus (sensu lato) under laboratory conditions. Parasit Vectors 2021; 14:300. [PMID: 34090481 PMCID: PMC8180032 DOI: 10.1186/s13071-021-04781-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 05/11/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Culicoides obsoletus (s.l.) is the most abundant Culicoides species in northern Europe and an important vector of bluetongue virus and Schmallenberg virus. Nevertheless, information on its subadult life stages remains scarce and no laboratory-reared colony exists. METHODS C. obsoletus (s.l.) adults were collected in Belgium and transferred to the laboratory in an attempt to establish a laboratory-reared colony. C. obsoletus (s.l.) were reared from eggs to adults at different temperatures (28 °C, 24 °C, 20/16 °C) and under different food regimes. RESULTS The most suitable temperature for rearing seemed to be 24 °C for most developmental parameters, but resulted in a biased 3:1 male/female sex ratio. The latter could be optimized to a 1:1 sex ratio when a 20/16 °C day/night temperature gradient was applied, but rearing at these low temperature conditions resulted in significantly lower egg hatching and pupation rates and a longer subadult development time. Independent of the rearing temperature, adding dung as an additional food source during larval development resulted in a significantly higher adult emergence rate and a decrease in subadult development time. Furthermore, blood-feeding rates of field-collected C. obsoletus (s.l.) were compared for different blood sources and feeding systems. The overall blood-feeding success was low and only successful with cotton pledgets (2.7% blood-fed midges) and through a membrane system with chicken skin (3.5% blood-fed midges). Higher feeding rates were obtained on cattle blood compared to sheep blood. CONCLUSIONS These results will help us to determine the necessary conditions to rear a viable laboratory colony of this important vector species, although further optimization is still required.
Collapse
Affiliation(s)
- Claudia Van den Eynde
- Sciensano, Enzootic, Vector-Borne and Bee Diseases, Groeselenberg 99, 1180, Brussels, Belgium.
| | - Charlotte Sohier
- Sciensano, Enzootic, Vector-Borne and Bee Diseases, Groeselenberg 99, 1180, Brussels, Belgium
| | - Severine Matthijs
- Sciensano, Enzootic, Vector-Borne and Bee Diseases, Groeselenberg 99, 1180, Brussels, Belgium
| | - Nick De Regge
- Sciensano, Enzootic, Vector-Borne and Bee Diseases, Groeselenberg 99, 1180, Brussels, Belgium
| |
Collapse
|
13
|
de Beer CJ, Boikanyo SNB, Venter GJ. Assessment of the Hemotek® system for the in vitro feeding of field-collected Culicoides imicola (Diptera: Ceratopogonidae) in South Africa. MEDICAL AND VETERINARY ENTOMOLOGY 2021; 35:177-186. [PMID: 32990991 DOI: 10.1111/mve.12484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/27/2020] [Accepted: 09/04/2020] [Indexed: 06/11/2023]
Abstract
The optimising and standardisation of in vitro blood feeding protocols for field-collected Culicoides species (Diptera: Ceratopogonidae) will be of essence for the comparison of the vector competencies of various populations of viruses of veterinary importance and the establishment of laboratory colonies of putative vector species. A custom-made feeding chamber to accommodate the small size of Culicoides imicola Kieffer was designed for the commercially available Hemotek® system and compared to existing membrane and cotton pledge feeding methods. High feeding rates coupled to higher mean blood meal volume than that of the existing OVI device indicated that the Hemotek system will be suitable for the feeding of field-collected Culicoides. The Hemotek system was subsequently used to identify factors that may affect feeding success in the laboratory. Evaluated factors were the source (host) and temperature of the blood meal, time of the day of feeding, the position of the blood reservoir in relation to the midges and exposure time to the blood. While only feeding orientation and the temperature of the blood source seems to significantly affect the feeding rate, all the factors did influence the volume of blood consumed.
Collapse
Affiliation(s)
- C J de Beer
- Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Insect Pest Control Laboratory, Vienna, Austria
- Epidemiology, Vectors and Parasites, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
| | - S N B Boikanyo
- Epidemiology, Vectors and Parasites, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
| | - G J Venter
- Epidemiology, Vectors and Parasites, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
| |
Collapse
|
14
|
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. MEDICAL AND VETERINARY ENTOMOLOGY 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] [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.
Collapse
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
| |
Collapse
|
15
|
de Beer CJ, Boikanyo SNB, Venter GJ, Mans B. The applicability of spectrophotometry for the assessment of blood meal volume inartificially fed Culicoides imicola in South Africa. MEDICAL AND VETERINARY ENTOMOLOGY 2021; 35:141-146. [PMID: 32841397 DOI: 10.1111/mve.12473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
The volume of the blood meal of haematophagous insects will determine the number of infective particles taken up during feeding and may as such denote the minimum dose needed to infect a competent vector. Culicoides midges resort among the smallest of haematophagous vectors and determining and comparing their blood meal volumes may be challenging. Collected Culicoides imicola females were fed on defibrinated bovine blood through a Parafilm® membrane using a Hemotek® system. After feeding, the weight of pools of 10 engorged females was compared to that of 10 unfed females to determine the volume of blood imbibed. After weighing, the pools were homogenized and their absorbance read at 410 nm. Spectrophotometer readings were then converted to blood meal volumes using calibration curves, obtained by the dilution of known volumes of blood used for feeding. Although the mean blood meal volumes determined spectrophotometrically (0.06 μL), differed significantly (P < 0.01) from those obtained by weighing (0.07 μL), the range in blood meal volumes determined spectrophotometrically (0.03-0.08 μL) and by weighing (0.01-0.11 μL) was positively correlated (r = 0.7; P < 0.01). Both methods can be used to determine the blood meal volume.
Collapse
Affiliation(s)
- C J de Beer
- Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Insect Pest Control Laboratory, Vienna, Austria
- Epidemiology, Vectors and Parasites, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
| | - S N B Boikanyo
- Epidemiology, Vectors and Parasites, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
| | - G J Venter
- Epidemiology, Vectors and Parasites, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
| | - B Mans
- Epidemiology, Vectors and Parasites, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
- Department of Life and Consumer Sciences, University of South Africa, Florida, South Africa
| |
Collapse
|
16
|
Saroya Y, Gottlieb Y, Klement E. The effect of ambient temperature fluctuations on Culicoides biting midges population dynamics and activity in dairy farms: a longitudinal study. MEDICAL AND VETERINARY ENTOMOLOGY 2021; 35:68-78. [PMID: 32815188 DOI: 10.1111/mve.12470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 07/10/2020] [Accepted: 07/18/2020] [Indexed: 06/11/2023]
Abstract
The effect of climatic factors on the presence of Culicoides Latreille (Diptera: Ceratopogonidae) was previously studied. Nevertheless, lack of laboratory rearing data hampers species-specific prediction of weather fluctuations effect on population size. To determine fluctuations in population size in the field, we recorded Culicoides and other Nematocerans in seven Israeli dairy farms over two-years (2011-2012) and analysed the association of their dynamics with fluctuations in ambient temperature and total rainfall. In six farms, the most abundant species were Culicoides imicola Kieffer and Culicoides schultzei (Enderlein) gp., primarily composed of parous females, and in one farm Culicoides obsoletus (Meigen) gp., mostly nulliparous females, were dominant. While the total number of insects was similar in both years, Culicoides numbers were significantly higher in 2012, but appeared later in the season and reached a higher peak. A multi-variable linear regression model demonstrated positive association of C. imicola and C. schultzei numbers with the monthly multi-annual ambient temperature and its specific deviation, but not with monthly rainfall. C. obsoletus populations peaked at spring and sharply decreased when temperature exceeded 20 °C, and were best modelled by adding quadratic terms. Weather-specific estimation of population size under field conditions may enable to predict outbreaks intensity of Culicoides-borne viruses.
Collapse
Affiliation(s)
- Y Saroya
- Koret School of Veterinary Medicine, Robert H. Smith Faculty of Agriculture, food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Y Gottlieb
- Koret School of Veterinary Medicine, Robert H. Smith Faculty of Agriculture, food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - E Klement
- Koret School of Veterinary Medicine, Robert H. Smith Faculty of Agriculture, food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| |
Collapse
|
17
|
Shults P, Cohnstaedt LW, Adelman ZN, Brelsfoard C. Next-generation tools to control biting midge populations and reduce pathogen transmission. Parasit Vectors 2021; 14:31. [PMID: 33413518 PMCID: PMC7788963 DOI: 10.1186/s13071-020-04524-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/05/2020] [Indexed: 02/06/2023] Open
Abstract
Biting midges of the genus Culicoides transmit disease-causing agents resulting in a significant economic impact on livestock industries in many parts of the world. Localized control efforts, such as removal of larval habitat or pesticide application, can be logistically difficult, expensive and ineffective if not instituted and maintained properly. With these limitations, a population-level approach to the management of Culicoides midges should be investigated as a means to replace or supplement existing control strategies. Next-generation control methods such as Wolbachia- and genetic-based population suppression and replacement are being investigated in several vector species. Here we assess the feasibility and applicability of these approaches for use against biting midges. We also discuss the technical and logistical hurdles needing to be addressed for each method to be successful, as well as emphasize the importance of addressing community engagement and involving stakeholders in the investigation and development of these approaches.
Collapse
Affiliation(s)
- Phillip Shults
- Texas A&M University, 370 Olsen Blvd, College Station, TX, 77843, USA.
| | - Lee W Cohnstaedt
- USDA-ARS Arthropod Borne Animal Disease Research Unit, 1515 College Ave, Manhattan, KS, 66502, USA
| | - Zach N Adelman
- Texas A&M University, 370 Olsen Blvd, College Station, TX, 77843, USA
| | | |
Collapse
|
18
|
Tracking Community Timing: Pattern and Determinants of Seasonality in Culicoides (Diptera: Ceratopogonidae) in Northern Florida. Viruses 2020; 12:v12090931. [PMID: 32854272 PMCID: PMC7552033 DOI: 10.3390/v12090931] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/18/2020] [Accepted: 08/24/2020] [Indexed: 11/19/2022] Open
Abstract
Community dynamics are embedded in hierarchical spatial–temporal scales that connect environmental drivers with species assembly processes. Culicoides species are hematophagous arthropod vectors of orbiviruses that impact wild and domestic ruminants. A better sense of Culicoides dynamics over time is important because sympatric species can lengthen the seasonality of virus transmission. We tested a putative departure from the four seasons calendar in the phenology of Culicoides and the vector subassemblage in the Florida panhandle. Two years of weekly abundance data, temporal scales, persistence and environmental thresholds were analyzed using a tripartite Culicoides β-diversity based modeling approach. Culicoides phenology followed a two-season regime and was explained by stream flow and temperature, but not rainfall. Species richness fit a nested pattern where the species recruitment was maximized during spring months. Midges were active year-round, and two suspected vectors species, Culicoides venustus and Culicoides stellifer, were able to sustain and connect the seasonal modules. Persistence suggests that Orbivirus maintenance does not rely on overwintering and that viruses are maintained year-round, with the seasonal dynamics resembling subtropical Culicoides communities with temporal-overlapping between multivoltine species. Viewing Culicoides-borne orbiviruses as a time-sensitive community-based issue, our results help to recommend when management operations should be delivered.
Collapse
|
19
|
Continuous Cell Lines from the European Biting Midge Culicoides nubeculosus (Meigen, 1830). Microorganisms 2020; 8:microorganisms8060825. [PMID: 32486323 PMCID: PMC7356041 DOI: 10.3390/microorganisms8060825] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 05/25/2020] [Accepted: 05/28/2020] [Indexed: 01/15/2023] Open
Abstract
Culicoides biting midges (Diptera: Ceratopogonidae) transmit arboviruses of veterinary or medical importance, including bluetongue virus (BTV) and Schmallenberg virus, as well as causing severe irritation to livestock and humans. Arthropod cell lines are essential laboratory research tools for the isolation and propagation of vector-borne pathogens and the investigation of host-vector-pathogen interactions. Here we report the establishment of two continuous cell lines, CNE/LULS44 and CNE/LULS47, from embryos of Culicoides nubeculosus, a midge distributed throughout the Western Palearctic region. Species origin of the cultured cells was confirmed by polymerase chain reaction (PCR) amplification and sequencing of a fragment of the cytochrome oxidase 1 gene, and the absence of bacterial contamination was confirmed by bacterial 16S rRNA PCR. Both lines have been successfully cryopreserved and resuscitated. The majority of cells examined in both lines had the expected diploid chromosome number of 2n = 6. Transmission electron microscopy of CNE/LULS44 cells revealed the presence of large mitochondria within cells of a diverse population, while arrays of virus-like particles were not seen. CNE/LULS44 cells supported replication of a strain of BTV serotype 1, but not of a strain of serotype 26 which is not known to be insect-transmitted. These new cell lines will expand the scope of research on Culicoides-borne pathogens.
Collapse
|
20
|
Erram D, Burkett-Cadena N. Laboratory Rearing of Culicoides stellifer (Diptera: Ceratopogonidae), a Suspected Vector of Orbiviruses in the United States. JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:25-32. [PMID: 31602460 DOI: 10.1093/jme/tjz154] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Indexed: 06/10/2023]
Abstract
Laboratory rearing procedures of Culicoides stellifer Coquillett (Diptera: Ceratopogonidae) were evaluated with an aim towards colonization of this species. Eggs collected from field-collected gravid females were placed on 0.25% agar slants and given a diet of 1) nematodes (Panagrellus redivivus Linnaeus), 2) nematodes + lactalbumin and yeast (LY), 3) microbes from nematode medium, and 4) tap water (autoclaved). Complete larval development to adult stage occurred only in two treatments: 1) nematodes and 2) nematodes + LY. Culicoides stellifer larvae could not survive beyond 1 wk on a diet of microbes alone or in the sterile water treatment. Larval survival rates were high using nematode diet (79.2 ± 11.3% [mean ± SE]) but were slightly lower in the nematode + LY group (66.5 ± 19.6%). Larval stage lasted ~21 d in both treatments. Sex ratio of F1 adults was ~1:1 (M:F) using nematode diet but was male biased (~2:1) with nematode + LY diet. These findings collectively suggest that a microbial community is required for midge larvae, either to support invertebrate prey base or as a potential food source. But in the present study, the supplied microbes alone were not sufficient to support midge survival/development. It appears that other nutritional components may also be essential to support the larval survival/development of C. stellifer. Overall, a simple diet of bacterial feeding nematodes and their associated microorganisms can be used to rear C. stellifer larvae under laboratory conditions. However, captive mating in F1 adults poses a major obstacle for successful colonization of this species currently.
Collapse
Affiliation(s)
- Dinesh Erram
- Florida Medical Entomology Laboratory, University of Florida, FL
| | | |
Collapse
|
21
|
Grimaud Y, Guis H, Chiroleu F, Boucher F, Tran A, Rakotoarivony I, Duhayon M, Cêtre-Sossah C, Esnault O, Cardinale E, Garros C. Modelling temporal dynamics of Culicoides Latreille (Diptera: Ceratopogonidae) populations on Reunion Island (Indian Ocean), vectors of viruses of veterinary importance. Parasit Vectors 2019; 12:562. [PMID: 31775850 PMCID: PMC6880491 DOI: 10.1186/s13071-019-3812-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 11/15/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Reunion Island regularly faces outbreaks of epizootic haemorrhagic disease (EHD) and bluetongue (BT), two viral diseases transmitted by haematophagous midges of the genus Culicoides (Diptera: Ceratopogonidae) to ruminants. To date, five species of Culicoides are recorded in Reunion Island in which the first two are proven vector species: Culicoides bolitinos, C. imicola, C. enderleini, C. grahamii and C. kibatiensis. Meteorological and environmental factors can severely constrain Culicoides populations and activities and thereby affect dispersion and intensity of transmission of Culicoides-borne viruses. The aim of this study was to describe and predict the temporal dynamics of all Culicoides species present in Reunion Island. METHODS Between 2016 and 2018, 55 biweekly Culicoides catches using Onderstepoort Veterinary Institute traps were set up in 11 sites. A hurdle model (i.e. a presence/absence model combined with an abundance model) was developed for each species in order to determine meteorological and environmental drivers of presence and abundance of Culicoides. RESULTS Abundance displayed very strong heterogeneity between sites. Average Culicoides catch per site per night ranged from 4 to 45,875 individuals. Culicoides imicola was dominant at low altitude and C. kibatiensis at high altitude. A marked seasonality was observed for the three other species with annual variations. Twelve groups of variables were tested. It was found that presence and/or abundance of all five Culicoides species were driven by common parameters: rain, temperature, vegetation index, forested environment and host density. Other parameters such as wind speed and farm building opening size governed abundance level of some species. In addition, Culicoides populations were also affected by meteorological parameters and/or vegetation index with different lags of time, suggesting an impact on immature stages. Taking into account all the parameters for the final hurdle model, the error rate by Normalized Root mean Square Error ranged from 4.4 to 8.5%. CONCLUSIONS To our knowledge, this is the first study to model Culicoides population dynamics in Reunion Island. In the absence of vaccination and vector control strategies, determining periods of high abundance of Culicoides is a crucial first step towards identifying periods at high risk of transmission for the two economically important viruses they transmit.
Collapse
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, 97715 Sainte-Clotilde, La Réunion France
- CIRAD, UMR ASTRE, 97490 Sainte-Clotilde, La Réunion France
| | - Hélène Guis
- CIRAD, UMR ASTRE, 101 Antananarivo, Madagascar
- ASTRE, University of Montpellier, CIRAD, INRA, Montpellier, France
- Epidemiology and clinical research unit, Institut Pasteur of Madagascar, Antananarivo, Madagascar
- FOFIFA DRZVP, Antananarivo, Madagascar
| | | | - Floriane Boucher
- CIRAD, UMR ASTRE, 97490 Sainte-Clotilde, La Réunion France
- ASTRE, University of Montpellier, CIRAD, INRA, Montpellier, France
| | - Annelise Tran
- CIRAD, UMR ASTRE, 97490 Sainte-Clotilde, La Réunion France
- ASTRE, University of Montpellier, CIRAD, INRA, Montpellier, France
- CIRAD, UMR TETIS, 97490 Sainte-Clotilde, La Réunion France
- TETIS, University of Montpellier, Montpellier, France
| | - Ignace Rakotoarivony
- ASTRE, University of Montpellier, CIRAD, INRA, Montpellier, France
- CIRAD, UMR ASTRE, 34398 Montpellier, France
| | - Maxime Duhayon
- ASTRE, University of Montpellier, CIRAD, INRA, Montpellier, France
- CIRAD, UMR ASTRE, 34398 Montpellier, France
| | - Catherine Cêtre-Sossah
- CIRAD, UMR ASTRE, 97490 Sainte-Clotilde, La Réunion France
- ASTRE, University of Montpellier, CIRAD, INRA, Montpellier, France
| | - Olivier Esnault
- GDS Réunion, 1 rue du Père Hauck, 97418 La Plaine des Cafres, La Réunion France
| | - Eric Cardinale
- CIRAD, UMR ASTRE, 97490 Sainte-Clotilde, La Réunion France
- ASTRE, University of Montpellier, CIRAD, INRA, Montpellier, France
| | - Claire Garros
- CIRAD, UMR ASTRE, 97490 Sainte-Clotilde, La Réunion France
- ASTRE, University of Montpellier, CIRAD, INRA, Montpellier, France
| |
Collapse
|
22
|
Leta S, Fetene E, Mulatu T, Amenu K, Jaleta MB, Beyene TJ, Negussie H, Revie CW. Modeling the global distribution of Culicoides imicola: an Ensemble approach. Sci Rep 2019; 9:14187. [PMID: 31578399 PMCID: PMC6775326 DOI: 10.1038/s41598-019-50765-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 09/17/2019] [Indexed: 11/09/2022] Open
Abstract
Culicoides imicola is a midge species serving as vector for a number of viral diseases of livestock, including Bluetongue, and African Horse Sickness. C. imicola is also known to transmit Schmallenberg virus experimentally. Environmental and demographic factors may impose rapid changes on the global distribution of C. imicola and aid introduction into new areas. The aim of this study is to predict the global distribution of C. imicola using an ensemble modeling approach by combining climatic, livestock distribution and land cover covariates, together with a comprehensive global dataset of geo-positioned occurrence points for C. imicola. Thirty individual models were generated by ‘biomod2’, with 21 models scoring a true skill statistic (TSS) >0.8. These 21 models incorporated weighted runs from eight of ten algorithms and were used to create a final ensemble model. The ensemble model performed very well (TSS = 0.898 and ROC = 0.991) and indicated high environmental suitability for C. imicola in the tropics and subtropics. The habitat suitability for C. imicola spans from South Africa to southern Europe and from southern USA to southern China. The distribution of C. imicola is mainly constrained by climatic factors. In the ensemble model, mean annual minimum temperature had the highest overall contribution (42.9%), followed by mean annual maximum temperature (21.1%), solar radiation (13.6%), annual precipitation (11%), livestock distribution (6.2%), vapor pressure (3.4%), wind speed (0.8%), and land cover (0.1%). The present study provides the most up-to-date predictive maps of the potential distributions of C. imicola and should be of great value for decision making at global and regional scales.
Collapse
Affiliation(s)
- Samson Leta
- Addis Ababa University, College of Veterinary Medicine and Agriculture, P. O. Box 34, Bishoftu, Ethiopia.
| | - Eyerusalem Fetene
- Addis Ababa University, College of Veterinary Medicine and Agriculture, P. O. Box 34, Bishoftu, Ethiopia
| | - Tesfaye Mulatu
- National Animal Health Diagnostic and Investigation Centre (NAHDIC), P. O. Box 04, Sebeta, Ethiopia
| | - Kebede Amenu
- Addis Ababa University, College of Veterinary Medicine and Agriculture, P. O. Box 34, Bishoftu, Ethiopia
| | - Megarsa Bedasa Jaleta
- Addis Ababa University, College of Veterinary Medicine and Agriculture, P. O. Box 34, Bishoftu, Ethiopia
| | - Tariku Jibat Beyene
- Addis Ababa University, College of Veterinary Medicine and Agriculture, P. O. Box 34, Bishoftu, Ethiopia.,Center for Outcome Research and Epidemiology, Kansas State University, Manhattan, Kansas, USA
| | - Haileleul Negussie
- Addis Ababa University, College of Veterinary Medicine and Agriculture, P. O. Box 34, Bishoftu, Ethiopia
| | - Crawford W Revie
- Department of Computing and Information Sciences, University of Strathclyde, Livingstone Tower (14.01), 26 Richmond Street, Glasgow, G1 1XQ, Scotland, UK
| |
Collapse
|
23
|
Venter GJ, Boikanyo SNB, de Beer CJ. The influence of temperature and humidity on the flight activity of Culicoides imicola both under laboratory and field conditions. Parasit Vectors 2019; 12:4. [PMID: 30606269 PMCID: PMC6318895 DOI: 10.1186/s13071-018-3272-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 12/19/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Insight into the factors that regulate the circadian host-seeking flight activity of Culicoides vectors (Diptera: Ceratopogonidae) will be of importance to assess the risk of transmission of Culicoides-borne pathogens. This study aimed to determine the impact of temperature and humidity on the flight activity of Culicoides imicola Kieffer, and other livestock associated Culicoides species, under both laboratory and field conditions. METHODS Batches of 500 field-collected C. imicola females were acclimatized at a predetermined range of temperatures (10-29 °C) and relative humidity (34-85%). After acclimatization, these females, prompted by a light source, were allowed to escape through a transparent plastic funnel into a paper cup, where they were counted after an hour. Flight activity under field conditions was determined seasonally by hourly light trap collections done overnight at four sites near cattle. RESULTS Experiments conducted at various test conditions in the laboratory indicated that flight activity started at 13 °C. Peak in activity was observed between 16 °C to 18 °C, and temperatures above 20 °C seemingly inhibit flight. Under field conditions, a peak in numbers collected was observed immediately after sunset. With mean nocturnal temperatures below 19 °C, more than 74% of the Culicoides were collected within two to three hours after sunset. With mean nocturnal temperature above 19 °C, the peak in numbers at sunset was sustained until after midnight, with somewhat higher numbers collected after midnight once temperatures dropped below 20 °C. No peak in numbers was observed at dawn. Although very low numbers were collected during the day, which partly may have been a result of the collecting method, Culicoides were present throughout periods of 24 hours. Humidity seemed to play a minor role in the regulation of flight activity. CONCLUSIONS Abundance and species diversity results as obtained in this study indicated a high level of risk of virus transmission in the first hours following sunset. A strong relationship was found between host-seeking activity, and hence trap efficiency, and within limits, temperature. Light traps primarily measure flight activity and may as such underestimate adult abundance of C. imicola if deployed at temperatures outside thresholds of 16-20 °C.
Collapse
Affiliation(s)
- Gert J Venter
- Epidemiology, Parasites and Vectors, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa. .,Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa.
| | - Solomon N B Boikanyo
- Epidemiology, Parasites and Vectors, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
| | - Chantel J de Beer
- Epidemiology, Parasites and Vectors, Agricultural Research Council-Onderstepoort Veterinary Research, Pretoria, South Africa
| |
Collapse
|
24
|
Braverman Y, Chizov-Ginzburg A, Eldor H, Mumcuoglu KY. Overview and features of larval developmental sites of biting midges species associated with livestock in Israel with implications to their control. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2018; 14:204-211. [PMID: 31014731 DOI: 10.1016/j.vprsr.2018.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 11/14/2018] [Accepted: 11/19/2018] [Indexed: 02/07/2023]
Abstract
The larval developmental sites of Culicoides species were assessed from 1155 samples collected during the years 1969-2003. Culicoides circumscriptus was most prolific in mud with medium organic matter with proportional representation of 55.8%. Culicoides imicola breeds mainly in damp mixture of rotten, decomposed animal dung with or without some mud, with proportional representation of 97.2%. Culicoides obsoletus was found mostly in rotten banana stumps, with proportional representation of almost 100%. Culicoides puncticollis was found in mud with a medium amount of organic matter with proportional representation of 35.6%. Culicoides distinctipennis showed 22.2% proportional representation for mud poor in organic matter. Culicoides schultzei gr. was most prolifically in mud rich in organic matter with proportional representation of 6.2%. Culicoides cataneii was most prolifically in mud with a medium amount of organic matter with proportional representation of 1.8%. Maximum duration time to emergence from the larval developmental sites ranged from seven weeks in C. obsoletus to fourteen weeks in C. circumscriptus and nine weeks in C. imicola. All the studied species breed throughout the year. Significant innate differences in the proportions of the sexes were found in the emergence of six species.
Collapse
Affiliation(s)
- Y Braverman
- Kimron Veterinary Institute, Bet Dagan, Israel.
| | | | - H Eldor
- Yoshpe Street 13, Hod Ha'Sharon, Israel
| | - K Y Mumcuoglu
- Parasitology Unit, Department of Microbiology and Molecular Genetics, The Hebrew University - Hadassah Medical School, The Kuvin Center for the Study of Infectious and Tropical Diseases, Jerusalem, Israel
| |
Collapse
|
25
|
Wilson AJ, Harrup LE. Reproducibility and relevance in insect-arbovirus infection studies. CURRENT OPINION IN INSECT SCIENCE 2018; 28:105-112. [PMID: 30551760 PMCID: PMC6299244 DOI: 10.1016/j.cois.2018.05.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/03/2018] [Accepted: 05/16/2018] [Indexed: 06/09/2023]
Abstract
Experimental infections of insects with arboviruses are performed to achieve a variety of objectives but principally to draw inferences about the potential role of field populations in transmission or to explore the molecular basis of vector-pathogen interactions. The design of such studies determines both their reproducibility and the extent to which their results can be extrapolated to natural environments, and is constrained by the resources available. We discuss recent findings regarding the effects of nutrition, the microbiome, co-infecting agents and feeding methods on the outcome of such experiments, and identify resource-efficient ways to increase their relevance and reproducibility, including the development of community standards for reporting such studies and better standards for cell line and colony authentication.
Collapse
Affiliation(s)
- Anthony James Wilson
- The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, United Kingdom.
| | - Lara Ellen Harrup
- The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey GU24 0NF, United Kingdom
| |
Collapse
|
26
|
Barceló C, Miranda MA. Bionomics of livestock-associated Culicoides (biting midge) bluetongue virus vectors under laboratory conditions. MEDICAL AND VETERINARY ENTOMOLOGY 2018; 32:216-225. [PMID: 29205857 DOI: 10.1111/mve.12286] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 10/30/2017] [Accepted: 11/02/2017] [Indexed: 06/07/2023]
Abstract
This research contributes to knowledge of the basic bionomic parameters of vector and non-vector Culicoides species. Field-collected gravid C. imicola and Obsoletus complex showed the longest lifespans in laboratory conditions. Culicoides paolae and C. circumscriptus seemed to be the most suitable species for laboratory rearing in view of their high oviposition rates, short lifecycles, long adult lifespans and female-biased sex ratios.
Collapse
Affiliation(s)
- C Barceló
- Laboratory of Zoology, Department of Biology, University of the Balearic Islands (UIB), Palma de Mallorca, Spain
| | - M A Miranda
- Laboratory of Zoology, Department of Biology, University of the Balearic Islands (UIB), Palma de Mallorca, Spain
| |
Collapse
|
27
|
Abstract
The performance of different bluetongue control measures related to both vaccination and protection from bluetongue virus (BTV) vectors was assessed. By means of a mathematical model, it was concluded that when vaccination is applied on 95% of animals even for 3 years, bluetongue cannot be eradicated and is able to re‐emerge. Only after 5 years of vaccination, the infection may be close to the eradication levels. In the absence of vaccination, the disease can persist for several years, reaching an endemic condition with low level of prevalence of infection. Among the mechanisms for bluetongue persistence, the persistence in the wildlife, the transplacental transmission in the host, the duration of viraemia and the possible vertical transmission in vectors were assessed. The criteria of the current surveillance scheme in place in the EU for demonstration of the virus absence need revision, because it was highlighted that under the current surveillance policy bluetongue circulation might occur undetected. For the safe movement of animals, newborn ruminants from vaccinated mothers with neutralising antibodies can be considered protected against infection, although a protective titre threshold cannot be identified. The presence of colostral antibodies interferes with the vaccine immunisation in the newborn for more than 3 months after birth, whereas the minimum time after vaccination of animal to be considered immune can be up to 48 days. The knowledge about vectors ecology, mechanisms of over‐wintering and criteria for the seasonally vector‐free period was updated. Some Culicoides species are active throughout the year and an absolute vector‐free period may not exist at least in some areas in Europe. To date, there is no evidence that the use of insecticides and repellents reduce the transmission of BTV in the field, although this may reduce host/vector contact. By only using pour‐on insecticides, protection of animals is lower than the one provided by vector‐proof establishments. This publication is linked to the following EFSA Supporting Publications article: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.EN-1182/full, http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.EN-1171/full
Collapse
|
28
|
Versteirt V, Balenghien T, Tack W, Wint W. A first estimation of Culicoides imicola and Culicoides obsoletus/Culicoides scoticus seasonality and abundance in Europe. ACTA ACUST UNITED AC 2017. [DOI: 10.2903/sp.efsa.2017.en-1182] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - T Balenghien
- Institut Agronomique et Vétérinaire Hassan II Madinat Al Irfane Morocco
| | | | - W Wint
- Environmental Research Group Oxford The United Kingdom
| |
Collapse
|
29
|
Carpenter S, Mellor PS, Fall AG, Garros C, Venter GJ. African Horse Sickness Virus: History, Transmission, and Current Status. ANNUAL REVIEW OF ENTOMOLOGY 2017; 62:343-358. [PMID: 28141961 DOI: 10.1146/annurev-ento-031616-035010] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
African horse sickness virus (AHSV) is a lethal arbovirus of equids that is transmitted between hosts primarily by biting midges of the genus Culicoides (Diptera: Ceratopogonidae). AHSV affects draft, thoroughbred, and companion horses and donkeys in Africa, Asia, and Europe. In this review, we examine the impact of AHSV critically and discuss entomological studies that have been conducted to improve understanding of its epidemiology and control. The transmission of AHSV remains a major research focus and we critically review studies that have implicated both Culicoides and other blood-feeding arthropods in this process. We explore AHSV both as an epidemic pathogen and within its endemic range as a barrier to development, an area of interest that has been underrepresented in studies of the virus to date. By discussing AHSV transmission in the African republics of South Africa and Senegal, we provide a more balanced view of the virus as a threat to equids in a diverse range of settings, thus leading to a discussion of key areas in which our knowledge of transmission could be improved. The use of entomological data to detect, predict and control AHSV is also examined, including reference to existing studies carried out during unprecedented outbreaks of bluetongue virus in Europe, an arbovirus of wild and domestic ruminants also transmitted by Culicoides.
Collapse
Affiliation(s)
- Simon Carpenter
- Vector-borne Viral Diseases Program, Pirbright Institute, Woking, Surrey GU24 0NF, United Kingdom;
| | - Philip S Mellor
- Vector-borne Viral Diseases Program, Pirbright Institute, Woking, Surrey GU24 0NF, United Kingdom;
| | | | - Claire Garros
- Cirad UMR15 CMAEE, 34398 Montpellier, Cedex 5, France
| | - Gert J Venter
- Parasites, Vectors, and Vector-Borne Diseases, Agricultural Research Council-Onderstepoort Veterinary Institute, Onderstepoort 0110, South Africa
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria 0001, South Africa
| |
Collapse
|
30
|
Steinke S, Lühken R, Kroischke F, Timmermann E, Kiel E. Comparison of emergence traps of different shape and translucency in the trapping of Culicoides (Diptera: Ceratopogonidae). Vet Parasitol 2016; 223:143-6. [PMID: 27198792 DOI: 10.1016/j.vetpar.2016.04.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 04/22/2016] [Accepted: 04/24/2016] [Indexed: 10/21/2022]
Abstract
Various types of emergence traps are available for investigations of the breeding habitats of Culicoides (Diptera: Ceratopogonidae). In order to assess the potential impact of the trap design on the trapping success, we compared the efficiency of opaque and white (more translucent) emergence traps and two trap shapes (cone-shaped and quadratic), to sample Culicoides emerging from cowpats. Significantly higher numbers of Culicoides chiopterus and Culicoides dewulfi were trapped with opaque traps, while there was no obvious effect of the trap shape. There were no distinct differences in the microclimate among different trap types.
Collapse
Affiliation(s)
- S Steinke
- Research Group Aquatic Ecology and Nature Conservation, Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Ammerländer Heerstraße 114-118, 26111 Oldenburg, Germany.
| | - R Lühken
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Hamburg, Germany
| | - F Kroischke
- Research Group Aquatic Ecology and Nature Conservation, Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Ammerländer Heerstraße 114-118, 26111 Oldenburg, Germany
| | - E Timmermann
- Research Group Aquatic Ecology and Nature Conservation, Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Ammerländer Heerstraße 114-118, 26111 Oldenburg, Germany
| | - E Kiel
- Research Group Aquatic Ecology and Nature Conservation, Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Ammerländer Heerstraße 114-118, 26111 Oldenburg, Germany
| |
Collapse
|
31
|
Harsha R, Mazumdar A. Laboratory rearing of immature Culicoides peregrinus Kieffer, a potential vector of bluetongue virus. MEDICAL AND VETERINARY ENTOMOLOGY 2015; 29:434-438. [PMID: 26396058 DOI: 10.1111/mve.12136] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 04/20/2015] [Accepted: 04/29/2015] [Indexed: 06/05/2023]
Abstract
Culicoides peregrinus (Kieffer) (Diptera: Ceratopogonidae) was reared from egg to adult using four different combinations of food and substrate (T1: absorbent cotton, mud broth with 2% yeast; T2: 1% agar, mud broth with 2% yeast; T3: absorbent cotton, nutrient broth; T4: absorbent cotton, 2% yeast). Field-collected engorged females exhibited mean fecundity of 82.45 ± 4.00. The highest rate of emergence and largest adults were obtained in T1, and the lowest rate of emergence was observed in T4. Two-way analyses of variance with post hoc Tukey tests showed significant differences in age at pupation, pupal weight and wing length among the various treatments, although the sex ratio was 1 : 1 in all food/substrate combinations. The successful rearing of immature C. peregrinus is an encouraging step towards the establishment of a laboratory colony of this prevalent species associated with livestock.
Collapse
Affiliation(s)
- R Harsha
- Entomology Research Unit, Department of Zoology, University of Burdwan, Burdwan, West Bengal, India
| | - A Mazumdar
- Entomology Research Unit, Department of Zoology, University of Burdwan, Burdwan, West Bengal, India
| |
Collapse
|
32
|
Lühken R, Steinke S, Hoppe N, Kiel E. Effects of temperature and photoperiod on the development of overwintering immature Culicoides chiopterus and C. dewulfi. Vet Parasitol 2015; 214:195-9. [DOI: 10.1016/j.vetpar.2015.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 09/03/2015] [Accepted: 10/01/2015] [Indexed: 10/22/2022]
|
33
|
Diarra M, Fall M, Lancelot R, Diop A, Fall AG, Dicko A, Seck MT, Garros C, Allène X, Rakotoarivony I, Bakhoum MT, Bouyer J, Guis H. Modelling the Abundances of Two Major Culicoides (Diptera: Ceratopogonidae) Species in the Niayes Area of Senegal. PLoS One 2015; 10:e0131021. [PMID: 26121048 PMCID: PMC4487250 DOI: 10.1371/journal.pone.0131021] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 05/26/2015] [Indexed: 11/19/2022] Open
Abstract
In Senegal, considerable mortality in the equine population and hence major economic losses were caused by the African horse sickness (AHS) epizootic in 2007. Culicoides oxystoma and Culicoides imicola, known or suspected of being vectors of bluetongue and AHS viruses are two predominant species in the vicinity of horses and are present all year-round in Niayes area, Senegal. The aim of this study was to better understand the environmental and climatic drivers of the dynamics of these two species. Culicoides collections were obtained using OVI (Onderstepoort Veterinary Institute) light traps at each of the 5 sites for three nights of consecutive collection per month over one year. Cross Correlation Map analysis was performed to determine the time-lags for which environmental variables and abundance data were the most correlated. C. oxystoma and C. imicola count data were highly variable and overdispersed. Despite modelling large Culicoides counts (over 220,000 Culicoides captured in 354 night-traps), using on-site climate measures, overdispersion persisted in Poisson, negative binomial, Poisson regression mixed-effect with random effect at the site of capture models. The only model able to take into account overdispersion was the Poisson regression mixed-effect model with nested random effects at the site and date of capture levels. According to this model, meteorological variables that contribute to explaining the dynamics of C. oxystoma and C. imicola abundances were: mean temperature and relative humidity of the capture day, mean humidity between 21 and 19 days prior a capture event, density of ruminants, percentage cover of water bodies within a 2 km radius and interaction between temperature and humidity for C. oxystoma; mean rainfall and NDVI of the capture day and percentage cover of water bodies for C. imicola. Other variables such as soil moisture, wind speed, degree days, land cover or landscape metrics could be tested to improve the models. Further work should also assess whether other trapping methods such as host-baited traps help reduce overdispersion.
Collapse
Affiliation(s)
- Maryam Diarra
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, Dakar, Sénégal
- Université Gaston Berger, Laboratoire d’Etudes et de Recherches en Statistiques et Développement, Saint-Louis, Sénégal
- * E-mail:
| | - Moussa Fall
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, Dakar, Sénégal
| | - Renaud Lancelot
- Cirad, UMR15 CMAEE, F-34398 Montpellier, France
- INRA, UMR1309 CMAEE, F-34398 Montpellier, France
| | - Aliou Diop
- Université Gaston Berger, Laboratoire d’Etudes et de Recherches en Statistiques et Développement, Saint-Louis, Sénégal
| | - Assane G. Fall
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, Dakar, Sénégal
| | - Ahmadou Dicko
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, Dakar, Sénégal
| | - Momar Talla Seck
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, Dakar, Sénégal
| | - Claire Garros
- Cirad, UMR15 CMAEE, F-34398 Montpellier, France
- INRA, UMR1309 CMAEE, F-34398 Montpellier, France
| | - Xavier Allène
- Cirad, UMR15 CMAEE, F-34398 Montpellier, France
- INRA, UMR1309 CMAEE, F-34398 Montpellier, France
| | - Ignace Rakotoarivony
- Cirad, UMR15 CMAEE, F-34398 Montpellier, France
- INRA, UMR1309 CMAEE, F-34398 Montpellier, France
| | - Mame Thierno Bakhoum
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, Dakar, Sénégal
| | - Jérémy Bouyer
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, Dakar, Sénégal
- Cirad, UMR15 CMAEE, F-34398 Montpellier, France
- INRA, UMR1309 CMAEE, F-34398 Montpellier, France
| | - Hélène Guis
- Cirad, UMR15 CMAEE, F-34398 Montpellier, France
- INRA, UMR1309 CMAEE, F-34398 Montpellier, France
| |
Collapse
|
34
|
Kaufmann C, Mathis A, Vorburger C. Sugar-feeding behaviour and longevity of European Culicoides biting midges. MEDICAL AND VETERINARY ENTOMOLOGY 2015; 29:17-25. [PMID: 25155520 DOI: 10.1111/mve.12086] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 06/23/2014] [Accepted: 07/03/2014] [Indexed: 06/03/2023]
Abstract
Most haematophagous insect vectors can also use sugar as an energy source; thus their sugar-feeding behaviour influences their longevity and blood-feeding rate and hence their vectorial capacity. Scant information is available on the sugar-feeding behaviour of Culicoides Latreille biting midges (Diptera: Ceratopogonidae), which are vectors of bluetongue and Schmallenberg viruses. The longevity of laboratory-reared Culicoides nubeculosus (Meigen) under fluctuating temperatures (16 and 28 °C) and with access to water or water and blood was on average 6.4 days and 8.9 days, respectively, which was around one third of the lifespan of siblings with access to sugar or sugar and blood (22.2 days and 27.1 days, respectively). Access to honeydew significantly increased the midge's longevity, whereas the provision of extrafloral nectaries had no impact. Females with access to sugar produced a significantly higher number of eggs (65.5 ± 5.2) than their starved sisters (45.4 ± 8.4). More than 80% of field-caught female Culicoides from the two most abundant European groups, Obsoletus (n = 2243) and Pulicaris (n = 805), were fructose-positive. Fructose-positivity was high in all physiological stages and no seasonal variability was noted. The high rate of natural sugar feeding of Culicoides offers opportunities for the development of novel control strategies using toxic sugar baits and for the monitoring of vector-borne diseases using sugar-treated FTA (nucleic acid preservation) cards in the field.
Collapse
Affiliation(s)
- C Kaufmann
- National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland
| | | | | |
Collapse
|
35
|
Purse BV, Carpenter S, Venter GJ, Bellis G, Mullens BA. Bionomics of temperate and tropical Culicoides midges: knowledge gaps and consequences for transmission of Culicoides-borne viruses. ANNUAL REVIEW OF ENTOMOLOGY 2015; 60:373-92. [PMID: 25386725 DOI: 10.1146/annurev-ento-010814-020614] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Culicoides midges are abundant hematophagous flies that vector arboviruses of veterinary and medical importance. Dramatic changes in the epidemiology of Culicoides-borne arboviruses have occurred since 1998, including the emergence of exotic viruses in northern temperate regions, increases in global disease incidence, and enhanced virus diversity in tropical zones. Drivers may include changes in climate, land use, trade, and animal husbandry. New Culicoides species and new wild reservoir hosts have been implicated in transmission, highlighting the dynamic nature of pathogen-vector-host interactions. Focusing on potential vector species worldwide and key elements of vectorial capacity, we review the sensitivity of Culicoides life cycles to abiotic and biotic factors. We consider implications for designing control measures and understanding impacts of environmental change in different ecological contexts. Critical geographical, biological, and taxonomic knowledge gaps are prioritized. Recent developments in genomics and mathematical modeling may enhance ecological understanding of these complex arbovirus systems.
Collapse
Affiliation(s)
- B V Purse
- NERC Centre for Ecology and Hydrology, Oxfordshire, OX10 8BB, United Kingdom;
| | | | | | | | | |
Collapse
|
36
|
Venter GJ, Labuschagne K, Majatladi D, Boikanyo SNB, Lourens C, Ebersohn K, Venter EH. Culicoides species abundance and potential over-wintering of African horse sickness virus in the Onderstepoort area, Gauteng, South Africa. J S Afr Vet Assoc 2014; 85:e1-e6. [PMID: 25686125 DOI: 10.4102/jsava.v85i1.1102] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 12/02/2013] [Accepted: 02/07/2014] [Indexed: 11/01/2022] Open
Abstract
In South Africa, outbreaks of African horse sickness (AHS) occur in summer; no cases are reported in winter, from July to September. The AHS virus (AHSV) is transmitted almost exclusively by Culicoides midges (Diptera: Ceratopogonidae), of which Culicoides imicola is considered to be the most important vector. The over-wintering mechanism of AHSV is unknown. In this study, more than 500 000 Culicoides midges belonging to at least 26 species were collected in 88 light traps at weekly intervals between July 2010 and September 2011 near horses in the Onderstepoort area of South Africa. The dominant species was C. imicola. Despite relatively low temperatures and frost, at least 17 species, including C. imicola, were collected throughout winter (June-August). Although the mean number of midges per night fell from > 50 000 (March) to < 100 (July and August), no midge-free periods were found. This study, using virus isolation on cell cultures and a reverse transcriptase polymerase chain reaction (RT-PCR) assay, confirmed low infection prevalence in field midges and that the detection of virus correlated to high numbers. Although no virus was detected during this winter period, continuous adult activity indicated that transmission can potentially occur. The absence of AHSV in the midges during winter can be ascribed to the relatively low numbers collected coupled to low infection prevalence, low virus replication rates and low virus titres in the potentially infected midges. Cases of AHS in susceptible animals are likely to start as soon as Culicoides populations reach a critical level.
Collapse
Affiliation(s)
- Gert J Venter
- Parasites, Vectors and Vector-borne Diseases Programme, Agricultural Research Council - Onderstepoort Veterinary Institute, South Africa; Department of Veterinary Tropical Diseases, University of Pretoria, South Africa.
| | | | | | | | | | | | | |
Collapse
|
37
|
Lühken R, Kiel E, Steinke S. Culicoides biting midge density in relation to the position and substrate temperature in a cattle dung heap. Parasitol Res 2014; 113:4659-62. [DOI: 10.1007/s00436-014-4182-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 10/10/2014] [Indexed: 11/28/2022]
|
38
|
Verhoef FA, Venter GJ, Weldon CW. Thermal limits of two biting midges, Culicoides imicola Kieffer and C. bolitinos Meiswinkel (Diptera: Ceratopogonidae). Parasit Vectors 2014; 7:384. [PMID: 25142029 PMCID: PMC4150952 DOI: 10.1186/1756-3305-7-384] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 08/08/2014] [Indexed: 01/16/2023] Open
Abstract
Background Culicoides imicola Kieffer and Culicoides bolitinos Meiswinkel (Diptera: Ceratopogonidae) are both of veterinary importance, being vectors of Schmallenberg, bluetongue and African horse sickness (AHS) viruses. Within South Africa, these Culicoides species show a marked difference in their abundances according to altitude, with C. imicola highly abundant in lower altitudes, but being replaced as the dominant species by C. bolitinos in cooler, high-altitude regions. Methods The thermal physiology of field collected adults of each species was determined to evaluate whether it could account for differences in their distribution and abundance. Critical thermal maxima (CTmax) and minima (CTmin), as well as upper and lower lethal temperatures (ULT and LLT) were assessed after acclimation temperatures of 19ˌC, 24ˌC and 29ˌC. Critical thermal limits were determined using an ecologically relevant rate of temperature change of 0.06ˌC.min−1. Results Significant differences in CTmin and CTmax were found between acclimation temperatures for C. imicola and C. bolitinos. In C. bolitinos, the LLT of individuals acclimated at 24ˌC was significantly improved (LLT50 = −6.01ˌC) compared with those acclimated at the other temperatures (LLT50 = −4ˌC). Acclimation had a weak (difference in LLT50 of only 1ˌC) but significant effect on the LLT of C. imicola. When CTmin, CTmax, LLT and ULT were superimposed on daily maximum and minimum temperature records from locations where each tested Culicoides species is dominant, it was found that temperatures frequently declined below the CTmin and LLT of C. imicola at the location where C. bolitinos was dominant. Conclusions The distribution and abundance of C. imicola is likely directly constrained by their relatively poor tolerance of lower temperatures. Results for C. bolitinos suggest that the adult phase is hardy, and it is hypothesised that the thermal biology of other life stages could determine their range. Electronic supplementary material The online version of this article (doi:10.1186/1756-3305-7-384) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- F Arné Verhoef
- Flies of Economic Significance Research Group, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa.
| | | | | |
Collapse
|
39
|
Modelling the Spatial Distribution of Culicoides imicola: Climatic versus Remote Sensing Data. REMOTE SENSING 2014. [DOI: 10.3390/rs6076604] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
40
|
Predicting spatio-temporal Culicoides imicola distributions in Spain based on environmental habitat characteristics and species dispersal. ECOL INFORM 2014. [DOI: 10.1016/j.ecoinf.2014.05.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
41
|
Nayduch D, Cohnstaedt LW, Saski C, Lawson D, Kersey P, Fife M, Carpenter S. Studying Culicoides vectors of BTV in the post-genomic era: resources, bottlenecks to progress and future directions. Virus Res 2013; 182:43-9. [PMID: 24355835 PMCID: PMC3979112 DOI: 10.1016/j.virusres.2013.12.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 12/08/2013] [Accepted: 12/09/2013] [Indexed: 12/05/2022]
Abstract
Culicoides sonorensis is the only colonized species of bluetongue virus vector. The development of a fully annotated genome for this species is in progress. Transcriptomic analyses are being employed to investigate functional elements of the genome, particularly genes involved in hematophagy, reproduction, development and vector competence.
Culicoides biting midges (Diptera: Ceratopogonidae) are a major vector group responsible for the biological transmission of a wide variety of globally significant arboviruses, including bluetongue virus (BTV). In this review we examine current biological resources for the study of this genus, with an emphasis on detailing the history of extant colonies and cell lines derived from C. sonorensis, the major vector of BTV in the USA. We then discuss the rapidly developing area of genomic and transcriptomic analyses of biological processes in vectors and introduce the newly formed Culicoides Genomics and Transcriptomics Alliance. Preliminary results from these fields are detailed and finally likely areas of future research are discussed from an entomological perspective describing limitations in our understanding of Culicoides biology that may impede progress in these areas.
Collapse
Affiliation(s)
- Dana Nayduch
- USDA-ARS, Center for Grain and Animal Health Research, Arthropod Borne Animal Diseases Research Unit, 1515 College Avenue, Manhattan, KS 66502, USA.
| | - Lee W Cohnstaedt
- USDA-ARS, Center for Grain and Animal Health Research, Arthropod Borne Animal Diseases Research Unit, 1515 College Avenue, Manhattan, KS 66502, USA
| | - Christopher Saski
- Clemson University Genomics Institute, Department of Genetics and Biochemistry, BRC #310, 105 Collins Street, Clemson, SC 29634, USA
| | - Daniel Lawson
- EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Paul Kersey
- EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Mark Fife
- Vector-borne Viral Disease Programme, The Pirbright Institute, Ash Road, Woking, Surrey GU24 0NF, UK
| | - Simon Carpenter
- Vector-borne Viral Disease Programme, The Pirbright Institute, Ash Road, Woking, Surrey GU24 0NF, UK
| |
Collapse
|
42
|
Does covering of farm-associated Culicoides larval habitat reduce adult populations in the United Kingdom? Vet Parasitol 2013; 201:137-45. [PMID: 24472769 PMCID: PMC3989040 DOI: 10.1016/j.vetpar.2013.11.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 11/25/2013] [Accepted: 11/29/2013] [Indexed: 11/23/2022]
Abstract
Culicoides biting midges (Diptera: Ceratopogonidae) are the biological vectors of a range of internationally important arboviruses of livestock, including bluetongue virus (BTV) and the recently emerging Schmallenberg virus (SBV). Culicoides species in the subgenus Avaritia (in the UK: Culicoides obsoletus Meigen, Culicoides scoticus Downes & Kettle, Culicoides dewulfi Goetghebuer and Culicoides chiopterus Meigen) have been implicated in BTV transmission in northern Europe and to a varying degree utilise cattle dung as a larval development substrate. The collection of cattle dung into heaps on farms provides a localised source of Culicoides emergence in close proximity to livestock. This study assesses the impact of covering dung heaps prior to the onset of adult Culicoides activity with the aim of reducing recruitment to the local adult populations at four livestock farms in England. Light suction trap catches of adult Culicoides from these farms were compared with those from four untreated control farms from a wide geographic range across the UK. It was demonstrated that implementing control of emergence from dung heaps did not have a significant impact upon the local adult subgenus Avaritia abundance at the treated farm holdings and that the onset of Culicoides activity was similarly unaffected. Use of this method in isolation is unlikely to have an effect in reducing the risk of BTV and SBV transmission. The implications of these results for control of farm-associated Culicoides in Europe are discussed.
Collapse
|
43
|
Veronesi E, Henstock M, Gubbins S, Batten C, Manley R, Barber J, Hoffmann B, Beer M, Attoui H, Mertens PPC, Carpenter S. Implicating Culicoides biting midges as vectors of Schmallenberg virus using semi-quantitative RT-PCR. PLoS One 2013; 8:e57747. [PMID: 23520481 PMCID: PMC3592918 DOI: 10.1371/journal.pone.0057747] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 01/24/2013] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND The recent unprecedented emergence of arboviruses transmitted by Culicoides biting midges in northern Europe has necessitated the development of techniques to differentiate competent vector species. At present these techniques are entirely reliant upon interpretation of semi-quantitative RT-PCR (sqPCR) data in the form of Cq values used to infer the presence of viral RNA in samples. METHODOLOGY/PRINCIPAL FINDINGS This study investigates the advantages and limitations of sqPCR in this role by comparing infection and dissemination rates of Schmallenberg virus (SBV) in two colony lines of Culicoides. Through the use of these behaviorally malleable lines we provide tools for demarcating arbovirus infection and dissemination rates in Culicoides which to date have prevented clear implication of primary vector species in northern Europe. The study demonstrates biological transmission of SBV in an arthropod vector, supporting the conclusions from field-caught Culicoides and provides a general framework for future assessment of vector competence of Culicoides for arboviruses using sqPCR. CONCLUSIONS/SIGNIFICANCE When adopting novel diagnostic technologies, correctly implicating vectors of arboviral pathogens requires a coherent laboratory framework to fully understand the implications of results produced in the field. This study illustrates these difficulties and provides a full examination of sqPCR in this role for the Culicoides-arbovirus system.
Collapse
Affiliation(s)
- Eva Veronesi
- VVD Program, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | - Mark Henstock
- VVD Program, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | - Simon Gubbins
- VVD Program, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | - Carrie Batten
- VVD Program, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | - Robyn Manley
- VVD Program, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | - James Barber
- VVD Program, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | - Bernd Hoffmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Houssam Attoui
- VVD Program, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| | | | - Simon Carpenter
- VVD Program, The Pirbright Institute, Pirbright, Surrey, United Kingdom
| |
Collapse
|
44
|
Rigot T, Conte A, Goffredo M, Ducheyne E, Hendrickx G, Gilbert M. Predicting the spatio-temporal distribution of Culicoides imicola in Sardinia using a discrete-time population model. Parasit Vectors 2012; 5:270. [PMID: 23174043 PMCID: PMC3561275 DOI: 10.1186/1756-3305-5-270] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 11/09/2012] [Indexed: 11/13/2022] Open
Abstract
Background Culicoides imicola KIEFFER, 1913 (Diptera: Ceratopogonidae) is the principal vector of Bluetongue disease in the Mediterranean basin, Africa and Asia. Previous studies have identified a range of eco-climatic variables associated with the distribution of C. imicola, and these relationships have been used to predict the large-scale distribution of the vector. However, these studies are not temporally-explicit and can not be used to predict the seasonality in C. imicola abundances. Between 2001 and 2006, longitudinal entomological surveillance was carried out throughout Italy, and provided a comprehensive spatio-temporal dataset of C. imicola catches in Onderstepoort-type black-light traps, in particular in Sardinia where the species is considered endemic. Methods We built a dynamic model that allows describing the effect of eco-climatic indicators on the monthly abundances of C. imicola in Sardinia. Model precision and accuracy were evaluated according to the influence of process and observation errors. Results A first-order autoregressive cofactor, a digital elevation model and MODIS Land Surface Temperature (LST)/or temperatures acquired from weather stations explained ~77% of the variability encountered in the samplings carried out in 9 sites during 6 years. Incorporating Normalized Difference Vegetation Index (NDVI) or rainfall did not increase the model's predictive capacity. On average, dynamics simulations showed good accuracy (predicted vs. observed r corr = 0.9). Although the model did not always reproduce the absolute levels of monthly abundances peaks, it succeeded in reproducing the seasonality in population level and allowed identifying the periods of low abundances and with no apparent activity. On that basis, we mapped C. imicola monthly distribution over the entire Sardinian region. Conclusions This study demonstrated prospects for modelling data arising from Culicoides longitudinal entomological surveillance. The framework explicitly incorporates the influence of eco-climatic factors on population growth rates and accounts for observation and process errors. Upon validation, such a model could be used to predict monthly population abundances on the basis of environmental conditions, and hence can potentially reduce the amount of entomological surveillance.
Collapse
Affiliation(s)
- Thibaud Rigot
- Biological control and spatial ecology LUBIES, Université Libre de Bruxelles, Av F,D, Roosevelt 50, Brussels, B-1050, Belgium.
| | | | | | | | | | | |
Collapse
|
45
|
Coetzee P, Van Vuuren M, Stokstad M, Myrmel M, Venter EH. Bluetongue virus genetic and phenotypic diversity: towards identifying the molecular determinants that influence virulence and transmission potential. Vet Microbiol 2012; 161:1-12. [PMID: 22835527 DOI: 10.1016/j.vetmic.2012.07.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2012] [Revised: 06/22/2012] [Accepted: 07/02/2012] [Indexed: 12/23/2022]
Abstract
Bluetongue virus (BTV) is the prototype member of the Orbivirus genus in the family Reoviridae and is the aetiological agent of the arthropod transmitted disease bluetongue (BT) that affects both ruminant and camelid species. The disease is of significant global importance due to its economic impact and effect on animal welfare. Bluetongue virus, a dsRNA virus, evolves through a process of quasispecies evolution that is driven by genetic drift and shift as well as intragenic recombination. Quasispecies evolution coupled with founder effect and evolutionary selective pressures has over time led to the establishment of genetically distinct strains of the virus in different epidemiological systems throughout the world. Bluetongue virus field strains may differ substantially from each other with regards to their phenotypic properties (i.e. virulence and/or transmission potential). The intrinsic molecular determinants that influence the phenotype of BTV have not clearly been characterized. It is currently unclear what contribution each of the viral genome segments have in determining the phenotypic properties of the virus and it is also unknown how genetic variability in the individual viral genes and their functional domains relate to differences in phenotype. In order to understand how genetic variation in particular viral genes could potentially influence the phenotypic properties of the virus; a closer understanding of the BTV virion, its encoded proteins and the evolutionary mechanisms that shape the diversity of the virus is required. This review provides a synopsis of these issues and highlights some of the studies that have been conducted on BTV and the closely related African horse sickness virus (AHSV) that have contributed to ongoing attempts to identify the molecular determinants that influence the virus' phenotype. Different strategies that can be used to generate BTV mutants in vitro and methods through which the causality between particular genetic modifications and changes in phenotype may be determined are also described. Finally examples are highlighted where a clear understanding of the molecular determinants that influence the phenotype of the virus may have contributed to risk assessment and mitigation strategies during recent outbreaks of BT in Europe.
Collapse
Affiliation(s)
- Peter Coetzee
- Department of Veterinary Tropical Diseases, University of Pretoria, Private Bag X04, Onderstepoort, Pretoria, 0110, South Africa.
| | | | | | | | | |
Collapse
|
46
|
Jiménez-Clavero MÁ. Animal viral diseases and global change: bluetongue and West Nile fever as paradigms. Front Genet 2012; 3:105. [PMID: 22707955 PMCID: PMC3374460 DOI: 10.3389/fgene.2012.00105] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 05/22/2012] [Indexed: 01/24/2023] Open
Abstract
Environmental changes have an undoubted influence on the appearance, distribution, and evolution of infectious diseases, and notably on those transmitted by vectors. Global change refers to environmental changes arising from human activities affecting the fundamental mechanisms operating in the biosphere. This paper discusses the changes observed in recent times with regard to some important arboviral (arthropod-borne viral) diseases of animals, and the role global change could have played in these variations. Two of the most important arboviral diseases of animals, bluetongue (BT) and West Nile fever/encephalitis (WNF), have been selected as models. In both cases, in the last 15 years an important leap forward has been observed, which has lead to considering them emerging diseases in different parts of the world. BT, affecting domestic ruminants, has recently afflicted livestock in Europe in an unprecedented epizootic, causing enormous economic losses. WNF affects wildlife (birds), domestic animals (equines), and humans, thus, beyond the economic consequences of its occurrence, as a zoonotic disease, it poses an important public health threat. West Nile virus (WNV) has expanded in the last 12 years worldwide, and particularly in the Americas, where it first occurred in 1999, extending throughout the Americas relentlessly since then, causing a severe epidemic of disastrous consequences for public health, wildlife, and livestock. In Europe, WNV is known long time ago, but it is since the last years of the twentieth century that its incidence has risen substantially. Circumstances such as global warming, changes in land use and water management, increase in travel, trade of animals, and others, can have an important influence in the observed changes in both diseases. The following question is raised: What is the contribution of global changes to the current increase of these diseases in the world?
Collapse
Affiliation(s)
- Miguel Á Jiménez-Clavero
- Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Valdeolmos, Spain
| |
Collapse
|
47
|
Venter GJ, Majatladi DM, Labuschagne K, Boikanyo SNB, Morey L. The attraction range of the Onderstepoort 220V light trap for Culicoides biting midges as determined under South African field conditions. Vet Parasitol 2012; 190:222-9. [PMID: 22704896 DOI: 10.1016/j.vetpar.2012.05.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 05/16/2012] [Accepted: 05/18/2012] [Indexed: 10/28/2022]
Abstract
Despite some limitations suction light traps are the primary tools used for the collection of Culicoides species (Diptera: Ceratopogonidae). The range of attraction of the Onderstepoort light trap is not known but an insight into the range of a trap will determine where the trap must be positioned relative to the hosts present, possible breeding sites and environmental structures in the trapping vicinity. It will therefore contribute to a more meaningful interpretation and comparison of results between trapping events. In the present study the number of Culicoides midges collected in a single trap was compared to those of traps made with an additional trap respectively 1m, 4m and 8.5m away from the first. Treatments between sites were rotated in three replicates of a 4×4 Latin square design. While interactions were found in traps 4m apart no statistically significant interactions were found when they were 8.5m apart. The range of attraction, indicated by the interaction between two traps, will be between 2m and 4m. In interpreting light trap results the limitations of this collection method needs to be taken into consideration.
Collapse
Affiliation(s)
- G J Venter
- ARC-Onderstepoort Veterinary Institute, Private Bag X5, Onderstepoort, 0110, South Africa.
| | | | | | | | | |
Collapse
|
48
|
Carpenter S, Wilson A, Barber J, Veronesi E, Mellor P, Venter G, Gubbins S. Temperature dependence of the extrinsic incubation period of orbiviruses in Culicoides biting midges. PLoS One 2011; 6:e27987. [PMID: 22125649 PMCID: PMC3220716 DOI: 10.1371/journal.pone.0027987] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 10/30/2011] [Indexed: 11/18/2022] Open
Abstract
Background The rate at which viruses replicate and disseminate in competent arthropod vectors is limited by the temperature of their environment, and this can be an important determinant of geographical and seasonal limits to their transmission by arthropods in temperate regions. Methodology/Principal Findings Here, we present a novel statistical methodology for estimating the relationship between temperature and the extrinsic incubation period (EIP) and apply it to both published and novel data on virus replication for three internationally important orbiviruses (African horse sickness virus (AHSV), bluetongue virus (BTV) and epizootic haemorrhagic disease virus (EHDV)) in their Culicoides vectors. Our analyses show that there can be differences in vector competence for different orbiviruses in the same vector species and for the same orbivirus in different vector species. Both the rate of virus replication (approximately 0.017-0.021 per degree-day) and the minimum temperature required for replication (11-13°C), however, were generally consistent for different orbiviruses and across different Culicoides vector species. The estimates obtained in the present study suggest that previous publications have underestimated the replication rate and threshold temperature because the statistical methods they used included an implicit assumption that all negative vectors were infected. Conclusions/Significance Robust estimates of the temperature dependence of arbovirus replication are essential for building accurate models of transmission and for informing policy decisions about seasonal relaxations to movement restrictions. The methodology developed in this study provides the required robustness and is superior to methods used previously. Importantly, the methods are generic and can readily be applied to other arbovirus-vector systems, as long as the assumptions described in the text are valid.
Collapse
Affiliation(s)
- Simon Carpenter
- Vector-borne Disease Programme, Institute for Animal Health, Woking, Surrey, United Kingdom.
| | | | | | | | | | | | | |
Collapse
|
49
|
Acevedo P, Ruiz-Fons F, Estrada R, Márquez AL, Miranda MA, Gortázar C, Lucientes J. A broad assessment of factors determining Culicoides imicola abundance: modelling the present and forecasting its future in climate change scenarios. PLoS One 2010; 5:e14236. [PMID: 21151914 PMCID: PMC2997795 DOI: 10.1371/journal.pone.0014236] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Accepted: 11/17/2010] [Indexed: 12/01/2022] Open
Abstract
Bluetongue (BT) is still present in Europe and the introduction of new serotypes from endemic areas in the African continent is a possible threat. Culicoides imicola remains one of the most relevant BT vectors in Spain and research on the environmental determinants driving its life cycle is key to preventing and controlling BT. Our aim was to improve our understanding of the biotic and abiotic determinants of C. imicola by modelling its present abundance, studying the spatial pattern of predicted abundance in relation to BT outbreaks, and investigating how the predicted current distribution and abundance patterns might change under future (2011-2040) scenarios of climate change according to the Intergovernmental Panel on Climate Change. C. imicola abundance data from the bluetongue national surveillance programme were modelled with spatial, topoclimatic, host and soil factors. The influence of these factors was further assessed by variation partitioning procedures. The predicted abundance of C. imicola was also projected to a future period. Variation partitioning demonstrated that the pure effect of host and topoclimate factors explained a high percentage (>80%) of the variation. The pure effect of soil followed in importance in explaining the abundance of C. imicola. A close link was confirmed between C. imicola abundance and BT outbreaks. To the best of our knowledge, this study is the first to consider wild and domestic hosts in predictive modelling for an arthropod vector. The main findings regarding the near future show that there is no evidence to suggest that there will be an important increase in the distribution range of C. imicola; this contrasts with an expected increase in abundance in the areas where it is already present in mainland Spain. What may be expected regarding the future scenario for orbiviruses in mainland Spain, is that higher predicted C. imicola abundance may significantly change the rate of transmission of orbiviruses.
Collapse
Affiliation(s)
- Pelayo Acevedo
- Biogeography, Diversity and Conservation Research Team, Department of Animal Biology, Faculty of Sciences, University of Malaga, Málaga, Spain.
| | | | | | | | | | | | | |
Collapse
|