The qPCR test detects the genome (DNA) of Equine Herpesvirus Type 4 (EHV-4).
Molecular detection of EHV-4 by PCR is the most sensitive, specific and accurate tool in assessing the infectivity of an affected horse
- 1 nasal or nasopharyngeal swab ( see AAEP guidelines)
- 5 mL - K3 EDTA tube
- 20 gr - placental or foetal tissue - sterile flask
- 2 to 5 working days
What is Herpesvirus Type 4?
- Equine Herpesvirus Type 4 (EHV-4) is a health risk to equine populations worldwide. Disease severity depends on multiple factors and may be latent in normal horses. And because clinical signs are similar to other respiratory diseases, it is difficult to make a definitive diagnosis from clinical presentation alone.
- EHV-4 infections are restricted to respiratory tract epithelium and associated lymph nodes,
- Infection of pregnant mares with EHV-4 strains rarely results in abortion.
- Like EHV-1 the EHV-4 establish latent infection in the majority of horses, which do not show clinical signs but may experience reactivation of infection and shedding of the virus when stressed.
- EHV-4 spread via aerosolised secretions from infected coughing horses, by direct and indirect (fomite) contact with nasal secretions.
- The most common way for EHV-4 to spread is by direct horse-to-horse contact.
- This virus is shed from infected horses via the respiratory tract.
- Horses may appear to be perfectly healthy yet spread the virus via the secretions from their nostrils.
- It is important to realize that EHV-4 can also be spread indirectly through contact with physical objects contaminated with infectious virus.
- The air around a horse that is shedding the virus can also be contaminated with infectious virus.
- Herd elimination of equine herpesviruses is virtually impossible because of the pervasiveness of the carrier state.
- Disease prevention, rather than treatment or attempts at eradication, offers the most effective means for controlling herpesvirus and its potential sequelae.
- Strategies aimed at reducing the economic and welfare impact associated with EHV-1 and EHV-4 respiratory infections include (1) prophylactic immunisation and (2) the implementation of preventive herd management practices.
- Subdivide horses into the small epidemiologically isolated closed groups.
- Minimize risks of exogenous and endogenous (stress induced viral reactivation) introduction of EHV-1.
- Maximize herd immunity through vaccination.
- Important measures in the case of an EHV-4 outbreak:
- Disinfection of areas contaminated by virus from the aborted foetus and placental membranes.
- Isolation of affected horses.
- Submission of clinical samples to a diagnostic laboratory.
- Implementation of hygienic procedures to prevent spread of infection (biosecurity).