| spatial and seasonal distribution of culicoides imicola in iberia in relation to the transmission of african horse sickness virus. | collections of biting midges were made over 24 months from sixty sites spread across iberia. information on the distribution of the vector of african horse sickness virus, culicoides imicola, from these 3119 samples showed that this species was annually present across south-western spain as far as 3 degrees 53'w and throughout most of portugal, up to 41 degrees 5'n. c. imicola was found in all areas where african horse sickness epizootics had occurred in 1987-90 and also in areas outside the epi ... | 1997 | 9061677 |
| duration of repellency of various synthetic and plant-derived preparations for culicoides imicola, the vector of african horse sickness virus. | objectives of the study were threefold: to find a safer and longer lasting repellent of the biting midge culicoides imicola than di-ethyl toluamide (deet), to examine whether the current recommendations in israel for application of repellents during an outbreak of c. imicola-borne pathogens are justified; and to examine whether plant-derived preparations that have no known detrimental side effects are potential replacements of synthetic repellents. of the seven repellents tested, those inferior ... | 1998 | 9785505 |
| african horse sickness epidemiology: vector competence of south african culicoides species for virus serotypes 3, 5 and 8. | the oral susceptibilities of 17 culicoides species to infection with african horse sickness virus (ahsv) serotypes 3, 5 and 8 were determined by feeding field-collected midges on ahsv infected horse blood. the mean titres of virus in the bloodmeals for the three serotypes of ahsv were between 5.7 and 6.5 log10 tcid50/ml. virus was detected, after 10 days incubation at 23.5 degrees c, in the culicoides imicola kieffer (diptera: ceratopogonidae) that had fed on blood containing ahsv 5 (8.5%) and 8 ... | 2000 | 11016430 |
| african horse sickness. | african horse sickness (ahs) is a reportable, noncontagious, arthropod-borne viral disease that results in severe cardiovascular and pulmonary illness in horses. ahs is caused by the orbivirus african horse sickness virus (ahsv), which is transmitted primarily by culicoides imicola in africa; potential vectors outside of africa include culicoides variipennis and biting flies in the genera stomoxys and tabanus. infection with ahsv has a high mortality rate. quick and accurate diagnosis can help p ... | 2011 | 23705175 |
| use of real-time quantitative reverse transcription polymerase chain reaction for the detection of african horse sickness virus replication in culicoides imicola. | despite its important role as vector for african horse sickness virus (ahsv), very little information is available on the dissemination of this virus in culicoides (avaritia) imicola kieffer (diptera: ceratopogonidae). this study reports on the applicability of a real-time quantitative reverse transcription polymerase chain reaction (rt-qpcr) to detect ahsv in dissected midges. a total of 96 midges were fed on ahsv-infected blood, after which one test group was dissected into head/thorax and abd ... | 2011 | 23327218 |
| delineation of the population genetic structure of culicoides imicola in east and south africa. | culicoides imicola kieffer, 1913 is the main vector of bluetongue virus (btv) and african horse sickness virus (ahsv) in sub-saharan africa. understanding the population genetic structure of this midge and the nature of barriers to gene flow will lead to a deeper understanding of bluetongue epidemiology and more effective vector control in this region. | 2015 | 26704134 |
| detection of african horse sickness virus in culicoides imicola pools using rt-qpcr. | african horse sickness (ahs) is an infectious, non-contagious arthropod-borne disease of equids, caused by the african horse sickness virus (ahsv), an orbivirus of the reoviridae family. it is endemic in sub-saharan africa and thought to be the most lethal viral disease of horses. this study focused on detection of ahsv in culicoides imicola (diptera: ceratopogonidae) pools by the application of a rt-qpcr. midges were fed on ahsv-infected blood. a single blood-engorged female was allocated to po ... | 2016 | 27232141 |
| culicoides species composition and environmental factors influencing african horse sickness distribution at three sites in namibia. | african horse sickness (ahs) is one of the most lethal infectious, non-contagious, vector-borne disease of equids. the causative agent, african horse sickness virus (ahsv) is transmitted via culicoides midges (diptera: ceratopogonidae). ahs is endemic to namibia but detailed studies of culicoides communities and influencing environmental parameters are limited. this study aims to determine the culicoides species composition at three different sites and to assess environmental parameters influenc ... | 2016 | 27491343 |
| culicoides (diptera: ceratopogonidae) midges, the vectors of african horse sickness virus--a host/vector contact study in the niayes area of senegal. | african horse sickness (ahs) is an equine disease endemic to senegal. the african horse sickness virus (ahsv) is transmitted to the mammalian hosts by midges of the culicoides latreille genus. during the last epizootic outbreak of ahs in senegal in 2007, 1,169 horses died from this disease entailing an estimated cost of 1.4 million euros. in spite of the serious animal health and economic implications of ahs, very little is known about determinants involved in transmission such as contact betwee ... | 2015 | 25604465 |
| insight on the larval habitat of afrotropical culicoides latreille (diptera: ceratopogonidae) in the niayes area of senegal, west africa. | certain biting midges species of the genus culicoides (diptera: ceratopogonidae) are vectors of virus to livestock worldwide. culicoides larval ecology has remained overlooked because of difficulties to identify breeding sites, methodological constraints to collect samples and lack of morphological tools to identify field-collected individuals to the species level. after the 2007 unforeseen outbreaks of african horse sickness virus (ahsv) in senegal (west africa), there is a need to identify sui ... | 2016 | 27549191 |
| seasonal dynamics of culicoides (diptera: ceratopogonidae) biting midges, potential vectors of african horse sickness and bluetongue viruses in the niayes area of senegal. | the african horse sickness epizootic in senegal in 2007 caused considerable mortality in the equine population and hence major economic losses. the vectors involved in the transmission of this arbovirus have never been studied specifically in senegal. this first study of the spatial and temporal dynamics of the culicoides (diptera: ceratopogonidae) species, potential vectors of african horse sickness in senegal, was conducted at five sites (mbao, parc hann, niague, pout and thies) in the niayes ... | 2014 | 24690198 |
| comparison of two trapping methods for culicoides biting midges and determination of african horse sickness virus prevalence in midge populations at onderstepoort, south africa. | culicoides biting midges (diptera: ceratopogonidae) are vectors of a variety of pathogens including african horse sickness virus (ahsv), a member of the family reoviridae, genus orbivirus. ahsv causes african horse sickness (ahs), an endemic disease of equids with an extremely high mortality rate in horses in sub-saharan africa. culicoides (avaritia) imicola kieffer is considered to be the principal vector of ahsv and is the dominant culicoides species in south africa. due to the global distribu ... | 2011 | 22014560 |
| a comparison of the susceptibility of the biting midge culicoides imicola to infection with recent and historical isolates of african horse sickness virus. | the susceptibility of culicoides (avaritia) imicola kiefer (diptera: ceratopogonidae) to 21 isolates representing all nine known serotypes of african horse sickness virus (ahsv), recovered from clinical cases of the disease in south africa during 1998-2004, was compared with its susceptibility to approximately 40-year-old isolates stored at the agricultural research council-onderstepoort veterinary institute. field-collected c. imicola were fed through a chicken skin membrane on sheep blood spik ... | 2010 | 20626628 |
| geographical and seasonal distribution of the bluetongue virus vector, culicoides imicola, in central italy. | following the first incursion of bluetongue virus (btv) into italy, the geographical and seasonal distribution of the biting midge culicoides imicola kieffer (diptera: ceratopogonidae), the main vector of btv and african horse sickness virus, was investigated in two regions of central italy (lazio and tuscany). surveillance of culicoides was carried out between july 2001 and december 2002 using light traps: 1917 collections were made in 381 trap sites, well distributed across both regions. durin ... | 2003 | 14651652 |
| spatial distribution of culicoides species in portugal in relation to the transmission of african horse sickness and bluetongue viruses. | surveillance of culicoides (diptera: ceratopogonidae) biting midge vectors was carried out at 87 sites within a 50 x 50 km grid distributed across portugal, using light trap collections at the time of peak midge abundance. culicoides imicola (kieffer) made up 66% of the 55 937 culicoides in these summer collections. it was highly abundant in the central eastern portion of portugal, between 37 degrees 5' n and 41 degrees 5' n, and in a band across to the lisbon peninsula (at around 38 degrees 5' ... | 2003 | 12823834 |
| using climate data to map the potential distribution of culicoides imicola (diptera: ceratopogonidae) in europe. | culicoides imicola, a vector of bluetongue virus and african horse sickness virus, is principally afro-asian in distribution, but has recently been found in parts of europe. a logistic regression model based on climate data (temperature, saturation deficit, rainfall and altitude) and the published distribution of c. imicola in iberia was developed and then applied to other countries in europe, to identify locations where c. imicola could become established. the model identified three temperature ... | 2001 | 11732415 |
| molecular differentiation of the old world culicoides imicola species complex (diptera, ceratopogonidae), inferred using random amplified polymorphic dna markers. | samples of seven of the 10 morphological species of midges of the culicoides imicola complex were considered. the importance of this species complex is connected to its vectorial capacity for african horse sickness virus (ahsv) and bluetongue virus (btv). consequently, the risk of transmission may vary dramatically, depending upon the particular cryptic species present in a given area. the species complex is confined to the old world and our samples were collected in southern africa, madagascar ... | 2001 | 11472544 |
| studies of the mortality rate of culicoides imicola in morocco. | daily mortality rates of female culicoides imicola were found for eight sites in morocco in 1994 and for six sites in 1995. the mortality rates were found by operating pirbright-type light traps for a number of consecutive nights in late summer or autumn and finding the parous rate assuming a feeding interval of 3 to 5 days. the mortality rates were calculated according to established methods. in morocco the daily mortality rates were found to vary from about 5% per day (arbaoua, 1994, 1995 and ... | 1998 | 9785502 |
| the culicoides vectors of african horse sickness virus in morocco: distribution and epidemiological implications. | african horse sickness (ahs) is a vector-borne, infectious disease of equids caused by african horse sickness virus. the only proven field vector of the virus is the biting midge culicoides imicola, although c. obsoletus and c. pulicaris are suspected vectors. in 1994-5 a total of 3887 light trap samples were collected from 22 sites distributed over most of morocco. culicoides imicola was found to be very widely distributed with the greatest catches in the low-lying north-western areas (between ... | 1998 | 9785501 |
| use of climatic data and satellite imagery to model the abundance of culicoides imicola, the vector of african horse sickness virus, in morocco. | african horse sickness (ahs) is a vector-borne, infectious disease of equids caused by african horse sickness virus (ahsv). the only proven field vector of the virus is the biting midge culicoides imicola. following a recent epizootic (1989-91) of ahs in morocco, light traps and automatic weather stations were operated for 2 years at twenty-two sites distributed over much of the country. the annually-averaged mean daily trap catch of c. imicola at these sites was negatively correlated with wind ... | 1998 | 9737597 |
| the spatial and seasonal distribution of african horse sickness and its potential culicoides vectors in morocco. | african horse sickness (ahs) is a vector-borne, infectious disease of equines that is caused by african horse sickness virus (ahsv). the only proven field vector is the biting midge culicoides imicola, although c. obsoletus and c. pulicaris are suspected vectors. there was a recent epizootic of ahs in iberia (1987-90) and morocco (1989-91). in 1994-45 a total of 3887 light trap samples were taken from twenty-two sites distributed over most of morocco. culicoides imicola was found to be very wide ... | 1997 | 9330250 |
| role of dogs (canis domesticus) as hosts for african horse sickness virus. | at bet dagan culicoides imicola kieffer, c. schultzei gp. (a mammal feeder), culex pipiens l. (a laboratory vector) and culex univittatus theobald were found in significantly (p < 0.05) smaller numbers near dogs than near other hosts, while phlebotomus spp. were found in significantly (p < 0.05) higher numbers in dog kennels than in other animal houses. some 400 blood meals of culicoides spp. from israel and zimbabwe were negative for canine blood. only 1 of 16 blood meals of culex pipiens caugh ... | 1996 | 8828119 |
| epizootiology and vectors of african horse sickness virus. | african horse sickness (ahs) virus causes a non-contagious, infectious, arthropod-borne disease of equines and is enzootic in sub-saharan africa. the major vectors are species of culicoides but mosquitoes and ticks may be involved. periodically the virus makes excursions beyond its enzootic zones but until recently has not been able to maintain itself outside these areas for more than 2-3 consecutive years. this is probably due to a number of factors including the absence of a long term vertebra ... | 1994 | 8001350 |
| the transmission and geographical spread of african horse sickness and bluetongue viruses. | african horse sickness virus (ahsv) and bluetongue virus (btv) are dsrna viruses within the genus orbivirus. both are able to cause non-contagious, infectious arthropod-borne diseases in their respective vertebrate hosts. ahsv infects equines and occasionally dogs, whereas btv replicates in ruminants. the disease caused by ahsv is usually at its most severe in horses, whereas certain breeds of sheep are particularly sensitive to btv infection. ahsv is endemic in sub-saharan africa but periodical ... | 1995 | 7741589 |
| the virtual absence of culicoides imicola (diptera: ceratopogonidae) in a light-trap survey of the colder, high-lying area of the eastern orange free state, south africa, and implications for the transmission of arboviruses. | altogether 52 078 culicoides biting midges of 35 species were collected during february 1990 and 1993 in 40 light-trap collections made on 17 cattle and/or sheep farms in the bethlehem and fouriesburg districts of the colder, high-lying eastern orange free state. culicoides (avaritia) bolitinos was by far the most abundant species, representing 50.9% of all specimens collected. culicoides (a.) imicola, considered to be the most common stock-associated species in the summer rainfall areas of sout ... | 1994 | 7501364 |
| isolations of african horse sickness virus from vector insects made during the 1988 epizootic in spain. | this paper describes the first isolations of african horse sickness virus (ahsv) from insects in spain. seven isolations of ahsv serotype 4 were made; four from culicoides imicola a known vector of the virus elsewhere, two from mixed pools of culicoides species not including c. imicola and one from blood engorged mosquitoes. three further isolations of ahsv serotype 4 were also made from horses kept adjacent to the insect collecting sites. this work presents the first definitive identification o ... | 1990 | 2209746 |
| the use of a membrane feeding technique to determine the infection rate of culicoides imicola (diptera, ceratopogonidae) for 2 bluetongue virus serotypes in south africa. | culicoides spp. in the lowveld of the northern transvaal, republic of south africa, were fed bluetongue virus serotypes 3 and 6 and african horsesickness virus serotype 1 through latex and chicken skin membranes. after an incubation period of 10 days at 25-27 degrees c, the infection rate of c. imicola for bluetongue virus serotypes 3 and 6 was established at 31% and 24% respectively. no african horsesickness virus could be recovered. the membrane feeding technique and handling procedures proved ... | 1991 | 1646980 |
| spatial and temporal variation in the abundance of culicoides biting midges (diptera: ceratopogonidae) in nine european countries. | biting midges of the genus culicoides (diptera: ceratopogonidae) are vectors of bluetongue virus (btv), african horse sickness virus and schmallenberg virus (sbv). outbreaks of both btv and sbv have affected large parts of europe. the spread of these diseases depends largely on vector distribution and abundance. the aim of this analysis was to identify and quantify major spatial patterns and temporal trends in the distribution and seasonal variation of observed culicoides abundance in nine count ... | 2018 | 29482593 |
| risk of introducing african horse sickness virus into the netherlands by international equine movements. | african horse sickness (ahs) is a vector-borne viral disease of equines that is transmitted by culicoides spp. and can have severe consequences for the horse industry in affected territories. a study was performed to assess the risk of introducing ahs virus (ahsv) into the netherlands (p_ahs) by international equine movements. the goal of this study was to provide more insight into (a) the regions and equine species that contribute most to this risk, (b) the seasonal variation in this risk, and ... | 2012 | 22341773 |
| susceptibility of culicoides species biting midges to deltamethrin-treated nets as determined under laboratory and field conditions in the balearic islands, spain. | culicoides latreille (diptera: ceratopogonidae) are vectors of several arboviruses, including bluetongue virus (btv) and african horse sickness virus (ahsv), which cause diseases in, respectively, sheep and cattle, and horses, and have economic repercussions mainly as a result of trade restrictions. insecticides can be used to reduce vector populations and hence the spread of disease. despite the economic importance of these diseases, relatively few studies have evaluated the efficacy of commerc ... | 2014 | 24890642 |
| <i>culicoides</i> species abundance and potential over-wintering of african horse sickness virus in the onderstepoort area, gauteng, south africa. | 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 be ... | 2014 | 28235307 |
| culicoides species abundance and potential over-wintering of african horse sickness virus in the onderstepoort area, gauteng, south africa. | 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 be ... | 2014 | 25686125 |
| culicoides species as potential vectors of african horse sickness virus in the southern regions of south africa. | african horse sickness (ahs), a disease of equids caused by the ahs virus, is of major concern in south africa. with mortality reaching up to 95% in susceptible horses and the apparent reoccurrence of cases in regions deemed non-endemic, most particularly the eastern cape, epidemiological research into factors contributing to the increase in the range of this economically important virus became imperative. the vectors, culicoides (diptera: ceratopogonidae), are considered unable to proliferate d ... | 2019 | 31172556 |