Table of Contents
How does bluetongue virus replicate?
Bluetongue virus (BTV) is the prototype vector-borne orbivirus (family Reoviridae). BTV serotypes 1–24 (typical BTVs) are transmitted by competent biting Culicoides midges and replicate in mammalian (BSR) and midge (KC) cells.
What virus causes bluetongue?
Bluetongue is an arthropod-borne non-contagious infectious disease of domestic and wild non-African ruminants. Under field conditions, the causative agent, bluetongue virus (BTV), is typically transmitted by Culicoides spp. insects (biting midges) following a bite to consume a blood meal from susceptible animals.
Which bluetongue virus protein is primarily involved in cellular attachment?
The two outer capsid proteins, VP2 and VP5, are involved in BTV entry into cells and in the delivery of the transcriptionally active core to the target cell cytoplasm.
How many strains of bluetongue are there?
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. BTV belongs to the family Reoviridae, genus Orbivirus with 20 recognised species in the genus.
What is BTV in sheep?
Bluetongue is a viral disease of ruminants worldwide. Clinical signs in sheep result from vascular endothelial damage, including edema of the muzzle, tongue, and coronary bands. Diagnosis is made on clinical suspicion and viral identification.
How does blue tongue work?
Swelling of the lips and tongue, accompanied by viral destruction of host blood vessels decreases the amount of oxygen that reaches the tongue tissue. Reduced oxygen delivery causes cyanosis, or the blue appearance of the tongue.
Why is it called bluetongue disease?
In cattle, constant changing of position of the feet gives bluetongue the nickname the dancing disease. Torsion of the neck (opisthotonos or torticollis) is observed in severely affected animals. Not all animals develop signs, but all those that do lose condition rapidly, and the sickest die within a week.
How does Blue Tongue work?
How many serotypes of Bluetongue virus are there in South Africa?
It is currently recognized that BT is endemic throughout most of South Africa and 22 of the 26 known serotypes have been detected in the region. Multiple serotypes circulate each vector season with the occurrence of different serotypes depending largely on herd-immunity.
How do you prevent blue tongue disease in sheep?
Because reservoirs for the virus (Angora goats, cattle, wildlife) exist eradication of the disease is impossible.
- Protect sheep from contact.
- Avoid low-lying wet areas.
- Allowing wool growth in late summer autumn.
- Use of insect repellents on the bare skin of sheep during an outbreak.
- Midges prefer cattle.
Is blue tongue a virus or bacteria?
Key Points. Bluetongue is a viral disease of domestic and wild ruminants transmitted by certain Culicoides midges. Clinical signs caused by vasculitis are more commonly observed in sheep than in other ruminants. Both vaccination and vector control are critical to control bluetongue.
What is bluetongue in sheep?
Bluetongue is a non-contagious, viral disease spread by biting insects. It affects species of ruminants, particularly sheep. Bluetongue causes many different symptoms in affected animals, including ulcers, sores, painful hooves, lameness and reproductive problems.
Why is it called Ranikhet disease?
Ranikhet disease, also known as New Castle disease, dates back to 1938 when the strain of avian paramyxovirus was first reported in Newcastle followed by Ranikhet, say experts. The disease is fatal for birds, chicken and other fowls.
What is Bluetongue virus?
Introduction Bluetongue virus (BTV) is a complex, non-enveloped, double stranded RNA (dsRNA) virus and is the archetypal member of the genus Orbivirus of the family Reoviridae. The family Reoviridae comprises of segmented dsRNA viruses, possessing icosahedral non-enveloped capsids with a double layered architecture.
What are the three layers of the Bluetongue virus?
The icosahedral bluetongue virus (BTV) particle (~80 nm diameter) is composed of three distinct protein layers. These include the subcore shell (VP3), core-surface layer (VP7) and outer capsid layer (VP2 and VP5).
How is Bluetongue virus (BLV) detected in blood of infected sheep?
Detection of bluetongue virus from blood of infected sheep by use of an antigen-capture enzyme-linked immunosorbent assay after amplification of the virus in cell culture. Am J Vet Res 54: 370-2. Mecham, J. O. 1997.