Bovine herpesvirus 4 - AbsoluteAstronomy.com

Introduction

Bovine herpesvirus 4 is a member of the Herpesviridae

Herpesviridae

The Herpesviridae are a large family of DNA viruses that cause diseases in animals, including humans. The members of this family are also known as herpesviruses. The family name is derived from the Greek word herpein , referring to the latent, recurring infections typical of this group of viruses...

family. It is part of the subfamily Gammaherpesvirinae

Gammaherpesvirinae

Gammaherpesvirinae is a subfamily of Herpesviridae distinguished by reproducing at a more variable rate than other subfamilies of Herpesviridae...

and genus Rhadinovirus

Rhadinovirus

Rhadinoviruses are a genus of herpesviruses that include the Human herpesvirus 8 , also known as Kaposi's sarcoma-associated herpesvirus , which causes Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman's disease. Other names for the Rhadinovirus genus include Rhadinoviridae...

.
Infection is normally sub-clinical but can cause reproductive disease in cattle such as endometritis

Endometritis

Endometritis refers to inflammation of the endometrium, the inner lining of the uterus. Pathologists have traditionally classified endometritis as either acute or chronic: acute endometritis is characterized by the presence of microabscesses or neutrophils within the endometrial glands, while...

, vulvovaginitis and also mastitis

Mastitis in dairy cattle

Mastitis in dairy cattle is the persistent, inflammatory reaction of the udder tissue. This potentially fatal mammary gland infection is the most common disease in dairy cattle in the United States. It is also the most costly to the dairy industry...

. Transmission is both vertical
Vertical transmission
Vertical transmission, also known as mother-to-child transmission, is the transmission of an infection or other disease from mother to child immediately before and after birth during the perinatal period. A pathogen's transmissibility refers to its capacity for vertical transmission...

and horizontal
Horizontal transmission
Horizontal transmission is the transmission of a bacterial, fungal, or viral infection between members of the same species that are not in a parent-child relationship....

. It can also be indirectly spread by fomites

Fomite

A fomite is any inanimate object or substance capable of carrying infectious organisms and hence transferring them from one individual to another. A fomite can be anything...

. Distribution is worldwide and the virus infects a range of ruminants

Ruminant

A ruminant is a mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first compartment of the stomach, principally through bacterial actions, then regurgitating the semi-digested mass, now known as cud, and chewing it again...

, including bison

Bison

Members of the genus Bison are large, even-toed ungulates within the subfamily Bovinae. Two extant and four extinct species are recognized...

, buffalo

African Buffalo

The African buffalo, affalo, nyati, Mbogo or Cape buffalo is a large African bovine. It is not closely related to the slightly larger wild Asian water buffalo, but its ancestry remains unclear...

, sheep and goats

Goat

The domestic goat is a subspecies of goat domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the Bovidae family and is closely related to the sheep as both are in the goat-antelope subfamily Caprinae. There are over three hundred distinct breeds of...

.

The disease may also be referred to as passenger virus and moyar virus.

Clinical Signs & Diagnosis

BHV-4 infection is often subclinical, with no observable clinical signs. However the virus may cause abortion
Abortion
Abortion is defined as the termination of pregnancy by the removal or expulsion from the uterus of a fetus or embryo prior to viability. An abortion can occur spontaneously, in which case it is usually called a miscarriage, or it can be purposely induced...

and retained foetal membranes, and if an infected fetus is born alive it may be weak. It can also cause mastitis
Mastitis in dairy cattle
Mastitis in dairy cattle is the persistent, inflammatory reaction of the udder tissue. This potentially fatal mammary gland infection is the most common disease in dairy cattle in the United States. It is also the most costly to the dairy industry...

in dairy cattle. It may be isolated from conjunctivitis and respiratory disease cases but it is unknown whether the EHV-4 is a primary or opportunistic pathogen in these cases.

Diagnosis is achieved by virus isolation (from tissues or secretions), PCR, ELISA
ELISA
Enzyme-linked immunosorbent assay , is a popular format of a "wet-lab" type analytic biochemistry assay that uses one sub-type of heterogeneous, solid-phase enzyme immunoassay to detect the presence of a substance in a liquid sample."Wet lab" analytic biochemistry assays involves detection of an...

, and indirect immunofluorescence
Immunofluorescence
Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is used primarily on biological samples. This technique uses the specificity of antibodies to their antigen to target fluorescent dyes to specific biomolecule targets within a cell, and therefore allows...

. It should be noted that because EHV-4 infection can be asymptomatic, the presence of the virus does not confirm that it was the cause of the observed clinical signs.

Treatment & Control

Treatment is symptomatic. The virus can remain latent
Virus latency
Virus latency is the ability of a pathogenic virus to lie dormant within a cell, denoted as the lysogenic part of the viral life cycle. A latent viral infection is a type of persistent viral infection which is distinguished from a chronic viral infection...

in recovered animals - shedding at times of stress, allowing the spread of disease to others. Appropriate hygiene and isolation measures can control disease. Vaccines exist in the USA but are not widely used.

Introduction

Clinical Signs & Diagnosis

Treatment & Control

See also