Bluetongue virus btv is an orbivirus that infects both domestic and wild ruminants and is transmitted by culicoides spp. Characterization of virus inclusion bodies in bluetongue. 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. The following defines an the occurrence of infection with btv. Cultured skin fibroblast cells derived from bluetongue. Pdf evidence of natural bluetongue virus infection among african. Stott jl, osburn bi, machlachlan nj 1983 diagnosis of bluetongue virus infection in cattle. 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. Bluetongue epidemiology in the european union volume 14. Research paper pathological characterization of ifnar. 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. 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.
It is a complex nonenveloped virus with a capsid and double stranded rna genome. 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. Btv does not establish persistent infections in ruminants thus survival of the. Bluetongue bt is a reportable disease of considerable socioeconomic concern and of major importance in the international trade of animals and animal products.
Detection and specific identification of btv is a multistep process. November, france reported a single case of btv4 in a bovine in haute savoie region oie, 2017. For the identification of viruses to serogroup level. Blue eyes in newborn calves associated with bluetongue. Immune response to bluetongue virus infection springerlink. The following defines the occurrence of infection with btv. Cattle are considered to be a natural reservoir host for the virus because viremia invariably is prolonged in btvinfected attle. Bovine infection with bluetongue virus with special emphasis on european. Bluetongue virus btv replicates in the cytoplasm of a wide variety of cell types and infection ultimately leads to cell death. The virus is transmitted by the midges culicoides imicola, culicoides variipennis, and. Novel serotype of bluetongue virus, western north america to the editor. Introduction of bluetongue virus infected culicoides sp. The virus which causes bt is identified as a member.
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. Members of the reoviridae family assemble virus factories within the cytoplasm of infected cells to replicate and assemble virus particles. There is still disagreement as to the extent of the clinical effects of bt in cattle. These observations suggest that t lymphocytes play an important role in protection against bluetongue virus. Although bluetongue virus is common in cattle in endemic areas, bluetongue disease is rare.
According to the international committee on taxonomy of viruses,5 btv is. Bluetongue virus can infect many domesticated and wild ruminants including sheep. Bluetongue disease is a noncontagious, insectborne, viral disease of ruminants, mainly sheep and less frequently cattle, goats, buffalo, deer, dromedaries, and antelope. Bluetongue virus is spread by insects called biting midges culicoides spp. Btv orbivirus, reoviridae is a vectorborne, doublestranded rna virus with 24 known serotypes, which causes a noncontagious infectious disease in ruminants. 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. Since 2006, bluetongue virus serotype 8 btv8 has spread across many countries in northwestern europe. Bluetongue is usually a much more serious disease in sheep than in cattle. 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 virus overwintered and reappeared as clinical infection in the same part of the eu in july 2007. Before 1998, bt was considered an exotic disease in europe. 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. 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 mammalian reservoir of the virus and are very important in the spread of the disease. 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. 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. Btv belongs to the family reoviridae, genus orbivirus with 20 recognised species in the genus.
Bluetongue virus infection of ruminants is common throughout tropical and temperate areas of the world. 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 arthropodborne orbivirus that infects sheep, wild ruminants and occasionally cattle. Pdf bluetongue is an international office of epizootics list a disease described as the centurys most economically devastating affliction of sheep find. Bluetongue virus can infect many domesticated and wild ruminants including sheep, goats, cattle, water buffalo, african buffalo syncerus caffer, bison bison spp. Overview of bluetongue generalized conditions merck.
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. Subclinically infected cattle can become viraemic 4 days postinfection. Chronic effects of bluetongue in sheep and cattle secondary bacterial infections of bluetongue virus induced lesions are common, affecting ulcerated areas and the lungs. Core and virus like particles were found within and at the. Pdf bluetongue virus causes febrile disease in sheep and a fatal hemorrhagic infection in north american whitetailed deer.
Viruses free fulltext differential localization of. 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. 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. Infection with bluetongue virus btv is common in a broad band across the world, which until recently stretched from 35s to 4050n. Other biting insects, such as ticks or sheep keds, may also transfer the virus. Btv species contain 24 recognised serotypes and are related to the viruses in. After 1998 new serotypes of bluetongue virus btv were discovered in. Serotype 26 nucleic acids were found at low levels in nasal and ocular secretions of goats, and this virus was isolated from ocular swabs. Cattle may be infected with the virus but rarely show disease. 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 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. 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. Pdf prevalence of bluetongue virus infection and associated risk.
Bluetongue virus btv infection of ruminants and vector culicoides midges is endemic throughout many tropical and temperate regions of the world. A closely related virus causes epizootic hemorrhagic disease ehd in deer. Bluetongue is an infectious arthropodborne viral disease primarily of domestic and wild ruminants. 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. Vibs were detected as early as 4 h post infection p. Bluetongue the center for food security and public health. Bluetongue virus can infect all ruminants but it usually only causes serious disease in sheep. Bluetongue infected cattle often only express one or two of these signs together with nonspecific features such as pyrexia, malaise and inappetence. Fatal bluetongue virus infection in an alpaca vicugna. The studies of verwoerd, huismans and others in the late 1960s and continuing to the present see chap. The aim of this study was to assess the pathogenicity and infection kinetics of bluetongue virus serotype 26 btv26 in goats. Differential diagnosis of bluetongue in cattle and sheep. 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. Bluetongue virus btv, the causative agent of bluetongue, is the prototype virus of the genus orbivirus in the family.
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. 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. Sensing and control of bluetongue virus infection in epithelial cells via rigi and mda5 helicases. Pdf detection of bluetongue virus1 and btv8 rna in. Although sheep are most severely affected, cattle are the main mammal reservoir of the virus and are critical in the disease epidemiology. 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 is an arboviral disease of domestic and wild ruminants characterized by vascular injury that produces widespread edema and tissue necrosis 1. Pdf sensing and control of bluetongue virus infection in.
The fatality rate is very high for this virus in deer but its effects on cattle and sheep are relatively mild. Among the arboviruses transmitted by culicoides, btv has the greatest economic impact. Detection of bluetongue virus 1 and btv8 rna in experimentally infected red deer. Although bluetongue virus is present in a monitored zone across northern australia, bluetongue disease has never been reported in australia. 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.
Lumpy skin disease and bluetongue training of trainers in fyr of macedonia. 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. An insect vector spreads the virus and it only occurs where the vector is present. Possible means of introduction of bluetongue virus. The animal in question tested positive for virus under the framework of premovement testing and has been humanely destroyed. 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.
67 832 1508 652 448 511 1284 670 1162 698 302 1040 477 1075 1218 869 878 813 850 550 1228 1399 964 902 1465 151 530 922 1173 194 320 427 163 756 905 1106 962 694 1382 619