Based information provided by the herdsmen on the date of confirmation of bluetongue virus infection at the dutch national reference laboratory in lelystad, the netherlands, all dairy cows from which affected calves were born were in their last third of pregnancy at the time when bluetongue was introduced into the herd. November, france reported a single case of btv4 in a bovine in haute savoie region oie, 2017. The aim of this study was to assess the pathogenicity and infection kinetics of bluetongue virus serotype 26 btv26 in goats. Btv orbivirus, reoviridae is a vectorborne, doublestranded rna virus with 24 known serotypes, which causes a noncontagious infectious disease in ruminants. Fatal bluetongue virus infection in an alpaca vicugna. This outbreak assessment also describes the risks of btv8 entry to the uk through the two main routes, namely, importation of infected livestock and windborne entry of infected midges from continental europe. Since 2006, bluetongue virus serotype 8 btv8 has spread across many countries in northwestern europe. Cattle may be infected with the virus but rarely show disease.
Bluetongue bt is a noncontagious, viral disease affecting domestic and wild ruminants primarily sheep and including cattle, goats, buffalo, antelope, deer, elk and camels that is transmitted by insects, particularly biting midges of the culicoides species. Pdf detection of bluetongue virus1 and btv8 rna in. Bluetongue infected cattle often only express one or two of these signs together with nonspecific features such as pyrexia, malaise and inappetence. The studies of verwoerd, huismans and others in the late 1960s and continuing to the present see chap. The manifestations of bluetongue range from an inapparent to a fatal outcome depending on the serotype and strain of the virus and the species, breed and age of the infected animal.
Bluetongue virus infection of ruminants is common throughout tropical and temperate areas of the world. Although bluetongue virus is present in a monitored zone across northern australia, bluetongue disease has never been reported in australia. From 1998 through 2005, at least 6 bt virus strains belonging to 5 serotypes btv1, btv2, btv4, btv9, and btv16 were continuously present in the mediterranean basin. Bluetongue virus, or btv, is a member of the orbivirus genus in the family reoviridae. In october 2008, a 15yearold female alpaca vicugna pacos housed at a breeding farm in. Bluetongue virus is spread by insects called biting midges culicoides spp. Other biting insects, such as ticks or sheep keds, may also transfer the virus. General provisions for the purposes of the terrestrial code, bluetongue is defined as an infection of ruminants and camelids with bluetongue virus btv that is transmitted by culicoides vectors.
The virus overwintered and reappeared as clinical infection in the same part of the eu in july 2007. Possible means of introduction of bluetongue virus. Clinical diagnosis disease outcome of infection ranges from inapparent, in the vast majority of infected animals, to fatal, in a proportion of infected sheep, goats, deer and some wild ruminants. Research paper pathological characterization of ifnar.
According to the international committee on taxonomy of viruses,5 btv is. Differential diagnosis of bluetongue in cattle and sheep. The following defines the occurrence of infection with btv. Pdf isolation and identification of bluetongue virus. General provisions for the purposes of the terrestrial code, bluetongue is defined as an infection of a case refers to an ruminants and camelids animal infected with bt bluetongue virus btv, that is transmitted by culicoides vectors.
Bluetongue virus btv is an orbivirus that infects both domestic and wild ruminants and is transmitted by culicoides spp. However, the virus may be spread by contaminated objects fomites, such as surgical equipment. Overview of bluetongue generalized conditions merck. The virus is transmitted by the midges culicoides imicola, culicoides variipennis, and. Before 1998, bt was considered an exotic disease in europe.
Detection and specific identification of btv is a multistep process. This situation changed in late summer 2006, when bluetongue virus serotype 8 bt8 first appeared in belgium and the netherlands and quickly spread to luxembourg, germany and northeastern france. In october 2007, the first case in denmark was detected, and from early august 2008 scattered cases in the southern parts of jutland, denmark, were reported, resulting in a total of 15 infected herds at the end of the year foedevarestyrelsen 2008. The following defines an the occurrence of infection with btv.
Bluetongue bt occurs principally in sheep and some species of wild ruminants, and bluetongue virus btv infection of cattle, goats and most wild ruminant species is typically asymptomatic or subclinical. Lumpy skin disease and bluetongue training of trainers in fyr of macedonia. Bluetongue is an infectious arthropodborne viral disease primarily of domestic and wild ruminants. Bluetongue outbreaks can result in millions of dollars in losses due to the impact on livestock health and notably in the loss of markets for livestock due to regulatory restrictions on animal movement to limit the spread of the disease. Characterization of virus inclusion bodies in bluetongue. Bluetongue epidemiology in the european union volume 14. Bluetongue virus can infect many domesticated and wild ruminants including sheep, goats, cattle, water buffalo, african buffalo syncerus caffer, bison bison spp. Core and virus like particles were found within and at the. Btv species contain 24 recognised serotypes and are related to the viruses in. A closely related virus causes epizootic hemorrhagic disease ehd in deer. For the identification of viruses to serogroup level. Although sheep are most severely affected, cattle are the main mammalian reservoir of the virus and are very important in the spread of the disease. Serotype 26 nucleic acids were found at low levels in nasal and ocular secretions of goats, and this virus was isolated from ocular swabs. This report presents combined independent work from two laboratories investigating the possible recovery of bluetongue virus btv over a protracted period after infection of both sheep and cattle.
Although sheep are most severely affected, cattle are the main mammal reservoir of the virus and are critical in the disease epidemiology. The fatality rate is very high for this virus in deer but its effects on cattle and sheep are relatively mild. Pdf evidence of natural bluetongue virus infection among african. Subclinically infected cattle can become viraemic 4 days postinfection. Disease report on september 22nd 2007, laboratory tests confirmed that bluetongue virus serotype 8 bt 8 was present in a nativeborn rare breed bovine animal on a farm in suffolk. Introduction of bluetongue virus infected culicoides sp. Pdf prevalence of bluetongue virus infection and associated risk.
Cultured skin fibroblast cells derived from bluetongue. The animal in question tested positive for virus under the framework of premovement testing and has been humanely destroyed. Pdf sensing and control of bluetongue virus infection in. A combined qualitative and quantitative approach has been used to examine the role of virus inclusion bodies vibs in the morphogenesis of bluetongue virus btv.
Immune response to bluetongue virus infection springerlink. Bluetongue bt, an arthropodtransmitted viral infection of domestic and wild ruminants, was first reported in africa by hutcheon 18 in 1881 under the name of epizootic catarrh. Bluetongue disease is a noncontagious, insectborne, viral disease of ruminants, mainly sheep and less frequently cattle, goats, buffalo, deer, dromedaries, and antelope. Novel serotype of bluetongue virus, western north america to the editor. Bluetongue virus can infect many domesticated and wild ruminants including sheep.
Although bluetongue virus is common in cattle in endemic areas, bluetongue disease is rare. Bluetongue virus btv forms virus inclusion bodies vibs that are aggregates of viral rna, certain viral proteins, and host factors, and have been shown to be sites of the initial assembly of transcriptionally active virus like particles. Bluetongue the center for food security and public health. Bluetongue bt is a reportable disease of considerable socioeconomic concern and of major importance in the international trade of animals and animal products. Among the arboviruses transmitted by culicoides, btv has the greatest economic impact.
Vibs were detected as early as 4 h post infection p. Bluetongue virus btv infection of ruminants and vector culicoides midges is endemic throughout many tropical and temperate regions of the world. Sensing and control of bluetongue virus infection in epithelial cells via rigi and mda5 helicases. Blue eyes in newborn calves associated with bluetongue. Animals recovered from infection with bluetongue virus type 3 and which received thoracic duct lymphocytes from an identical twin recently infected with the same bluetongue virus type were protected from challenge with bluetongue type 4.
Bluetongue virus btv, the causative agent of bluetongue, is the prototype virus of the genus orbivirus in the family. Out of a group of six goats housed in insect free accommodation, five were experimentally infected with btv26 and one was kept uninfected as an incontact control. There is still disagreement as to the extent of the clinical effects of bt in cattle. The virus which causes bt is identified as a member. Novel serotype of bluetongue virus, western north america. Pdf bluetongue is an international office of epizootics list a disease described as the centurys most economically devastating affliction of sheep find. Bluetongue is an arboviral disease of domestic and wild ruminants characterized by vascular injury that produces widespread edema and tissue necrosis 1. Bluetongue bt virus, an orbivirus of the reoviridae family encompassing 24 known serotypes, is transmitted to ruminants via certain species of biting midges culicoides spp. The first step involves the isolation of the virus from the animals blood or other tissues, followed by inoculation of embryonating chicken eggs ece. Bluetongue virus btv is an arthropodborne orbivirus that infects sheep, wild ruminants and occasionally cattle. There are 29 different types serotypes of bluetongue virus btv which can infect domestic animals such as sheep, goats, and cattle, along with wild animals like buffaloes, deer, antelope and camels. Bluetongue virus can infect all ruminants but it usually only causes serious disease in sheep.
The confirmation of bluetongue virus serotype 8 btv8 in the netherlands on august 17, 2006 marked the onset of the first outbreak of bluetongue in northwest europe. Viruses free fulltext differential localization of. Btv does not establish persistent infections in ruminants thus survival of the. Members of the reoviridae family assemble virus factories within the cytoplasm of infected cells to replicate and assemble virus particles. Detection of bluetongue virus 1 and btv8 rna in experimentally infected red deer. Bluetongue virus btv replicates in the cytoplasm of a wide variety of cell types and infection ultimately leads to cell death. After 1998 new serotypes of bluetongue virus btv were discovered in. It is a complex nonenveloped virus with a capsid and double stranded rna genome. An insect vector spreads the virus and it only occurs where the vector is present. Btv belongs to the family reoviridae, genus orbivirus with 20 recognised species in the genus. A recent hypothesis to explain the recurrence of bluetongue disease after winter seasonal absences of the vector has suggested a role for persistent infection of sheep.
For the purposes of the terrestrial code, bluetongue is defined as an infection of ruminants and camelids with bluetongue virus btv that is transmitted by culicoides vectors. Pdf bluetongue virus causes febrile disease in sheep and a fatal hemorrhagic infection in north american whitetailed deer. Although sheep are most severely affected, cattle are the main mammalian reservoir of the virus and are very important in the epidemiology of the disease. These observations suggest that t lymphocytes play an important role in protection against bluetongue virus. Chronic effects of bluetongue in sheep and cattle secondary bacterial infections of bluetongue virus induced lesions are common, affecting ulcerated areas and the lungs. Bluetongue is not contagious and is not spread by contact between animals. Stott jl, osburn bi, machlachlan nj 1983 diagnosis of bluetongue virus infection in cattle. Infection with bluetongue virus btv is common in a broad band across the world, which until recently stretched from 35s to 4050n. Bovine infection with bluetongue virus with special emphasis on european. Bluetongue is usually a much more serious disease in sheep than in cattle. Cattle are considered to be a natural reservoir host for the virus because viremia invariably is prolonged in btvinfected attle.
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