Bovine leukemia virus: Difference between revisions

Latest revision as of 16:32, 16 February 2025

Bovine Leukemia Virus[edit]

The Bovine Leukemia Virus (BLV) is a retrovirus that infects cattle, leading to a condition known as enzootic bovine leukosis. This virus is a member of the Deltaretrovirus genus, which also includes the Human T-lymphotropic virus. BLV primarily affects the immune system of cattle, leading to the proliferation of B lymphocytes.

Transmission[edit]

BLV is primarily transmitted through the transfer of infected blood and other bodily fluids. Common routes of transmission include:

Vertical transmission from dam to calf, either in utero or through colostrum and milk.
Horizontal transmission via blood-contaminated equipment, such as needles, dehorning tools, and ear tagging devices.
Insect vectors such as biting flies may also play a role in transmission.

Pathogenesis[edit]

Once inside the host, BLV targets B lymphocytes, integrating its genome into the host cell's DNA. This integration can lead to the transformation of infected cells, resulting in lymphocytosis and, in some cases, the development of lymphosarcoma. The majority of infected cattle remain asymptomatic, but a small percentage develop clinical signs of disease.

Clinical Signs[edit]

Most BLV-infected cattle do not show any clinical signs. However, in cases where the disease progresses, symptoms may include:

Diagnosis[edit]

Diagnosis of BLV infection can be achieved through several methods:

Serological testing to detect antibodies against BLV.
Polymerase chain reaction (PCR) to detect viral nucleic acids.
Histopathological examination of affected tissues.

Control and Prevention[edit]

Control of BLV infection involves management practices aimed at reducing transmission:

Implementing biosecurity measures to prevent the spread of infection.
Regular testing and culling of infected animals.
Use of single-use needles and equipment.
Pasteurization of milk to prevent vertical transmission.

Related Pages[edit]

Template:Bovine diseases

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-'''Bovine leukemia virus''' ('''BLV''') is a retrovirus that affects [[cattle]]. BLV is the causative agent of [[Enzootic Bovine Leukosis]] (EBL), a disease characterized by a benign growth of lymphoid tissue that can progress to [[lymphoma]] and [[leukemia]] in some cases. The virus is part of the [[Retroviridae]] family, specifically within the genus ''[[Deltaretrovirus]]''. BLV infection is widespread globally, affecting the health and productivity of cattle, and poses a significant economic burden on the [[dairy industry]] and [[beef industry]].
+== Bovine Leukemia Virus ==
-==Transmission==
+[[File:Foûboutaedje_fine_pea_ouy.JPG|thumb|right|Bovine leukemia virus particles under electron microscopy]]
-BLV is primarily transmitted through the transfer of bodily fluids between infected and uninfected animals. The most common routes of transmission include:
-* [[Blood]] transfer via contaminated needles, dehorning instruments, and other surgical tools.
-* [[Milk]] and [[colostrum]] from infected cows to calves.
-* Vertical transmission from an infected cow to her offspring during pregnancy.
-In addition, the virus can be spread through close contact, as it is present in various bodily fluids such as saliva, nasal secretions, and semen.
+The '''Bovine Leukemia Virus''' (BLV) is a [[retrovirus]] that infects [[cattle]], leading to a condition known as [[enzootic bovine leukosis]]. This virus is a member of the [[Deltaretrovirus]] genus, which also includes the [[Human T-lymphotropic virus]]. BLV primarily affects the [[immune system]] of cattle, leading to the proliferation of [[B lymphocytes]].
-==Clinical Signs and Diagnosis==
+== Transmission ==
-Most cattle infected with BLV are asymptomatic. However, a small percentage may develop persistent [[lymphocytosis]], which is an increase in the number of lymphocytes in the blood. Even fewer may progress to develop EBL, characterized by the development of tumors in various organs, including the [[heart]], [[abomasum]], [[spleen]], and [[lymph nodes]].
-Diagnosis of BLV is typically performed through serological tests such as the enzyme-linked immunosorbent assay (ELISA) or the agar gel immunodiffusion test (AGID), which detect antibodies to BLV in the blood. Polymerase chain reaction (PCR) tests can also be used to detect the presence of BLV DNA in blood or tissue samples.
+BLV is primarily transmitted through the transfer of infected [[blood]] and other bodily fluids. Common routes of transmission include:
-==Prevention and Control==
+* [[Vertical transmission]] from dam to calf, either in utero or through [[colostrum]] and [[milk]].
-There is currently no vaccine available for BLV, so control measures focus on reducing the risk of transmission. These measures include:
+* Horizontal transmission via [[blood]]-contaminated equipment, such as [[needles]], [[dehorning]] tools, and [[ear tagging]] devices.
-* Testing and culling infected animals.
+* [[Insect vectors]] such as [[biting flies]] may also play a role in transmission.
-* Using disposable needles and properly sterilizing surgical equipment.
-* Avoiding the pooling of milk for feeding calves.
-* Implementing good management practices to reduce stress and improve the overall health of the herd.
-==Economic Impact==
+== Pathogenesis ==
-The economic impact of BLV on the dairy and beef industries is significant. Infected cattle may suffer from reduced milk production, weight loss, increased susceptibility to other diseases, and decreased fertility. Additionally, the presence of BLV can restrict trade and export opportunities for affected herds.
-==Public Health Concerns==
+Once inside the host, BLV targets [[B lymphocytes]], integrating its [[genome]] into the host cell's [[DNA]]. This integration can lead to the transformation of infected cells, resulting in [[lymphocytosis]] and, in some cases, the development of [[lymphosarcoma]]. The majority of infected cattle remain asymptomatic, but a small percentage develop clinical signs of disease.
-While BLV is a disease of cattle, there has been some concern about the potential for zoonotic transmission, or the virus spreading from animals to humans. However, to date, there is no conclusive evidence that BLV infects humans or poses a risk to public health.
+== Clinical Signs ==
+Most BLV-infected cattle do not show any clinical signs. However, in cases where the disease progresses, symptoms may include:
+* [[Lymphadenopathy]]
+* [[Weight loss]]
+* Decreased [[milk production]]
+* [[Fever]]
+* [[Anorexia]]
+== Diagnosis ==
+Diagnosis of BLV infection can be achieved through several methods:
+* [[Serological testing]] to detect antibodies against BLV.
+* [[Polymerase chain reaction]] (PCR) to detect viral [[nucleic acids]].
+* [[Histopathological examination]] of affected tissues.
+== Control and Prevention ==
+Control of BLV infection involves management practices aimed at reducing transmission:
+* Implementing [[biosecurity]] measures to prevent the spread of infection.
+* Regular testing and culling of infected animals.
+* Use of [[single-use needles]] and equipment.
+* [[Pasteurization]] of milk to prevent vertical transmission.
+== Related Pages ==
-==See Also==
 * [[Retrovirus]]
-* [[Leukemia]]
+* [[Lymphosarcoma]]
-* [[Dairy farming]]
+* [[Bovine diseases]]
-* [[Beef farming]]
+* [[Enzootic bovine leukosis]]
-[[Category:Viral diseases of animals]]
+{{Viral diseases}}
-[[Category:Cattle diseases]]
+{{Bovine diseases}}
-[[Category:Retroviridae]]
-{{virus-stub}}
+[[Category:Animal viral diseases]]
+[[Category:Bovine diseases]]
+[[Category:Retroviruses]]