avian & livestock assay data sheet

Porcine lymphotropic herpesviruses (PLHV1, PLHV2 and PLHV3)

Test code: S0129 - Ultrasensitive detection of porcine lymphotropic herpesviruses type 1 and type 2 by real time PCR
Test code: S0228 - Ultrasensitive detection of porcine lymphotropic herpesvirus type 3 by real time PCR

Herpesviruses are widely distributed and have been found in insects, reptiles, amphibians and every species of bird and mammal. One important characteristic of herpesvirus infection is that the virus persists in the infected host for life and is frequently reactivated and shed. In pigs, five herpesviruses have been identified: pseudorabies virus, porcine cytomegalovirus (PCMV) and three recently identified lymphotrophic herpesviruses, PLHV-1, PLHV-2 and PLHV-3.

PLHV-1 and -2 are highly homologous to each other but not to PLHV-3. These two viruses are widespread in domestic pigs and are closely related to several ruminant gammaherpesviruses, most of which are etiologically implicated in the occurrence of malignant catarrhal fever (MCF), a lymphoproliferative inflammatory disease with an often fatal outcome. PLHV-1 and -2 are also related to Epstein-Barr virus, human herpesvirus-8 and other gammaherpesviruses.

A recent study (McMahon et al., 2006) in domestic pigs has shown that PLHV1 infections are most common, being found in 74% of animals tested, followed by PLHV3 at 45% and PLHV2 at 21%. Infections with multiple PLHV species were frequently detected.

Like porcine CMV, antibodies to PLHV have been found in a high percentage of swine herds worldwide. Because of the high prevalence of positive serology, serological identification of infected pigs is not possible. Many of these latent carriers remain unidentified, posing serious problems for research using the pig as a model. In xenotransplantation between pig and human, reactivation of these latent viruses can cause postransplantation failure. Molecular detection of these viruses is an important tool to provide rapid, sensitive and specific detection of the viral nucleic acid in suspected animals.

Utilities:

• Help confirm the disease causing agent
• Identify PLHV-1, PLHV-2 and PLHV-3 carriers
• Help ensure that animal colonies and populations are free of PLHVs
• Early prevention of spread of these viruses among animals
• Minimize human exposure to these viruses
• Safety monitoring of biological products that derive from animals

References:
McMahon, K.J., Minihan, D., Campion, E.M., Loughran, S.T., Allan, G., McNeilly, F. and Walls, D. (2006) Infection of pigs in Ireland with lymphotropic herpesviruses and relationship to postweaning multisystemic wasting syndrome. Vet. Microbiol. 116:60-68.

Specimen requirements: 0.2 ml whole blood in EDTA (purple top) tube, or 0.2 ml fresh, frozen or fixed tissue.

Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time PCR

Normal range: Nondetected