scholarly journals Interactions entre les orbivirus et leurs vecteurs Culicoides

Author(s):  
E. Veronesi ◽  
P. P.C. Mertens ◽  
P. Mellor ◽  
K. Darpel ◽  
S. Maan ◽  
...  

Bluetongue, African horse sickness and epizootic haemor­rhagic disease are non-contagious, infectious diseases, caused by orbiviruses transmitted by Culicoides biting midges. Recent incursions of bluetongue virus (BTV) into both Southern and Northern European countries have highlighted our lack of knowledge in the mechanisms involved in the transmission of orbiviruses, which are of importance in understanding their spread. This presentation will discuss preliminary results of vector competence studies and provide an overview of future investigations. An understanding of the rates and temperature limits of virus replication and effects of temperature on vector metabolism can provide simple tools to predict the probability of virus establishment and onwards transmission subsequent to new incursions. Experiments showed that it was possible to use KC cell lines originating from C. sonorensis embryos as a surrogate system to screen rapidly replication rates in prefer­ence to the classical method of infecting and incubating adult insects via membrane feeding on a blood/virus meal. Some of the issues that arose in the development of detection assays are examined. The value of these techniques is then discussed in relation to understanding the effect of laboratory passage history upon orbivirus infectivity and detection, and this is related to an overview of current BTV strains’ distribution. Finally, future areas of interest that may develop from these studies are described.

Author(s):  
K. Labuschagne ◽  
L.J. Gerber ◽  
I. Espie ◽  
S. Carpenter

Culicoides biting midges (Diptera: Ceratopogonidae) are responsible for the transmission of a large number of pathogens to livestock and wild animals. In this study the presence of the genus, using light traps based at four different sites within the National Zoological Gardens of South Africa, was investigated during 2002-2004. In total, 37 species were recorded, including large numbers of Culicoides imicola Kieffer, 1913, which is responsible for the transmission of economically important arboviruses in South Africa, Europe, Middle and Far East. These results are discussed with reference to the wider Culicoides fauna in the Onderstepoort area of South Africa, their vector competence as well as biosecurity at the National Zoological Gardens.


2012 ◽  
Vol 32 (10) ◽  
pp. S83-S84
Author(s):  
G. Lo Iacono ◽  
C. Robin ◽  
S. Gubbins ◽  
R. Newton ◽  
J. Wood

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1978
Author(s):  
Jumari Snyman ◽  
Gert J. Venter ◽  
Marietjie Venter

Culicoides-borne viruses such as bluetongue, African horse sickness, and Schmallenberg virus cause major economic burdens due to animal outbreaks in Africa and their emergence in Europe and Asia. However, little is known about the role of Culicoides as vectors for zoonotic arboviruses. In this study, we identify both veterinary and zoonotic arboviruses in pools of Culicoides biting midges in South Africa, during 2012–2017. Midges were collected at six surveillance sites in three provinces and screened for Alphavirs, Flavivirus, Orthobunyavirus, and Phlebovirus genera; equine encephalosis virus (EEV); and Rhaboviridae, by reverse transcription polymerase chain reaction. In total, 66/331 (minimum infection rate (MIR) = 0.4) pools tested positive for one or more arbovirus. Orthobunyaviruses, including Shuni virus (MIR = 0.1) and EEV (MIR = 0.2) were more readily detected, while only 2/66 (MIR = 0.1) Middelburg virus and 4/66 unknown Rhabdoviridae viruses (MIR = 0.0) were detected. This study suggests Culicoides as potential vectors of both veterinary and zoonotic arboviruses detected in disease outbreaks in Africa, which may contribute to the emergence of these viruses to new regions.


2021 ◽  
Author(s):  
Darine Slama ◽  
Emna Chaker ◽  
Hamouda Babba

Culicoides biting midges are tiny blood-feeding insects of several diseases with veterinary and public health significance, including Bluetongue in ruminants, African horse sickness in equids and filarial diseases like Onchocercosis and Mansonellosis affecting various species such as humans. Their identification depends basically on the microscope examination of key morphological characters. Consequently, identification keys are important to any non experiment working with these biting midges. The Tunisian fauna of Culicoides biting midges consists of 35 species, whose morphological delineation may be troublesome for non-taxonomists. In response to this situation, and for the first time a key to the adult Culicoides species in Tunisia was prepared.


Viruses ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 376 ◽  
Author(s):  
Franziska Sick ◽  
Martin Beer ◽  
Helge Kampen ◽  
Kerstin Wernike

Culicoides biting midges, small hematophagous dipterans, are the demonstrated or putative vectors of multiple arboviruses of veterinary and public health importance. Despite its relevance in disease spread, the ceratopogonid genus Culicoides is still a largely neglected group of species, predominantly because the major human-affecting arboviruses are considered to be transmitted by mosquitoes. However, when a pathogen is detected in a certain vector species, a thorough search for further vectors often remains undone and, therefore, the relevant vector species may remain unknown. Furthermore, for many hematophagous arthropods, true vector competence is often merely suspected and not experimentally proven. Therefore, we aim to illuminate the general impact of Culicoides biting midges and to summarize the knowledge about biting midge-borne disease agents using the order Bunyavirales, the largest and most diverse group of RNA viruses, as an example. When considering only viruses evidentially transmitted by Culicoides midges, the Simbu serogroup (genus Orthobunyavirus) is presumably the most important group within the virus order. Its members are of great veterinary importance, as a variety of simbuviruses, e.g., the species Akabane orthobunyavirus or Schmallenberg orthobunyavirus, induces severe congenital infections in pregnant animals. The major zoonotic representative of this serogroup occurs in South and Central America and causes the so-called Oropouche fever, an acute febrile illness in humans.


2015 ◽  
Vol 15 (6) ◽  
pp. 374-384 ◽  
Author(s):  
Robert S. Pfannenstiel ◽  
Bradley A. Mullens ◽  
Mark G. Ruder ◽  
Ludek Zurek ◽  
Lee W. Cohnstaedt ◽  
...  

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