The adoption of PCR (Polymerase Chain Reaction) and advanced diagnostic technologies over recent years has significantly improved the accuracy of identifying specific diseases, virus strains and their variants.
And one of the most noticeable achievements from the application of this technology has been in the identification of infectious bronchitis (IB).
Partly as a result of a collaboration between MSD Animal Health and service provider x-OvO Diagnostics, which is offering vets and their farming clients access to diagnostic technology, a comprehensive picture has emerged of the IB strains present on British poultry farms.
“The diagnosis of IB infections is complex and the scope of traditional tests such as ELISA and HI testing can be limited, in part due to cross-reactions between different virus strains,” says Richard Currie of x-OvO Diagnostics.
“However, PCR plus RNA sequencing allows very accurate identification of the virus that is present, allowing the veterinarian to advise on flock management and vaccine management programmes to optimise health status and performance.”
Keith Warner of The Minster Veterinary Practice was one the first poultry vets in the country to take advantage of the service, to get a quick and accurate diagnosis.
“In reviewing cases of likely IB challenge our priority is to establish as quickly as possible the full health background on the unit,” he says. “This includes the current and historic records of mortality, respiratory signs and scouring. We take swabs, blood samples and perform postmortem examinations, as well as studying and discussing health events on the unit for the preceding crops and weeks.
“If we believe that we need to look more directly at the specific challenge, we will take samples for submission to x-OvO.”
The ability to take and process tests quickly is a clear advantage over traditional virus testing methods and challenge studies that can take months.
Samples can be collected from one broiler crop and, if necessary, changes implemented for the next crop.
Mr Warner believes the sharing of information between all parties is key, “MSD Animal Health now has a big picture of the instances of IB throughout the UK and is actively involved in following up vaccine programmes to monitor their effectiveness.”
In addition to being able to identify specific IB virus strains, vets need to consider the value of cross-protection, using combinations of vaccines to protect birds against challenge by IB strains not present in the vaccines.
“It is certainly the case that, by utilising diagnostic technology, we have been able to demonstrate cross-protection from many of the leading IB vaccines, for example Nobilis IB Ma5 and Nobilis IB 4-91.”
Tibor Cserep at MSD Animal Health has been supporting vets and their clients with detailed interpretation and advice on IB diagnosis and the implementation of follow-up vaccine management programmes.
“When new, innovative technology becomes available the key is to be able to deliver it with the appropriate support,” he says. “This is very much the case with the x-OvO technology and IB. The combined approach of diagnostics, vaccines and case-by-case support had made the project a credible example of what is possible.”
But Dr Cserep believes that the benefits for the industry extend further than unit-by-unit diagnosis.
“As well as providing specific information to producers, a picture is building of the prevalence of several variant strains in UK ‘problem’ flocks, emphasising that different variants can wax and wane over time.” The Minster Poultry Practice’s experience reflects the success of the collaborative approach. “As one of the leading poultry veterinary practices there is an expectation that we should be working with the best available technology to support the veterinary capabilities we have,” says Mr Warner.
“Obviously the work does not start and finish with the testing – the ongoing veterinary input in co-operation with the producer will ultimately deliver the improvement that the technology makes possible,” he concludes.