Home News New Johne’s disease test could be available in SA by 2021

New Johne’s disease test could be available in SA by 2021

The promising new test for the fatal Johne's disease pledges to be both more rapid and sensitive in detecting the infectious agent in dairy cattle

Johne's disease is a contagious, chronic and sometimes fatal infection that manifests itself in the gut of affected animasl and progressively damages the intestines. In cattle this results in profuse and persistent diarrhoea, severe weight loss, loss of condition and infertility. Photo: Supplied.

The new test aimed at detecting an infectious agent that causes Johne’s disease in dairy cattle may only be accessible in 2021, says senior research associate at the Institute for Global Food Security (IGFS) and School of Biological Sciences at Queen’s University Belfast, Dr Antonio Foddai.

Foddai, who developed the test with his partner, Irene Grant, a professor of microbiology and food safety within the institute, says the ParaTb test is not on the market yet. Discussions with licensing partners have not been finalised due to the covid-19 pandemic.

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“We have already identified a couple of licencing partners who are interested in the test and would like to pursue with its large-scale production and commercialisation, but because of the current covid crisis the process has been delayed. We hope to have some news at some point next year, mid-March early April, but it is currently quite difficult to set any work schedule,” he says.

The ParaTb test promises to be both more rapid and sensitive in detecting the infectious agent (Mycobacterium avium subsp. paratuberculosis or MAP) of Johne’s disease in veterinary specimens. It is also showing greater detection capability than the milk enzyme-linked immunosorbent assay (Elisa) that is currently used.

Crucially it detects live infectious agents, not just antibodies against MAP as are detected by the milk Elisa.

Heath experts indicate that having access to the test could benefit many farmers because Johne’s disease is a contagious, chronic and sometimes fatal infection that affects cattle, sheep, goats, and certain game species.

It is also closely related to the organism that causes tuberculosis and it manifests in the gut and progressively damages the intestines of affected animals. In cattle this results in profuse and persistent diarrhoea, severe weight loss, loss of condition and infertility.

More accurate, rapid and quantitative results

Affected animals eventually and inevitably die and usually, signs are rarely evident until two or more years after the initial infection, which usually occurs shortly after birth of the calve.

The test was published in the open-access journal Applied Microbiology and Biotechnology. The scientist hope to now move to the applied stage of the science with further development and validation of their test for MAP infection at farm level.

Grant said, “As farmers will know, Johne’s disease is an endemic animal health issue worldwide, particularly in dairy herds. It is certainly present in Northern Ireland dairy herds, but the true prevalence of Johne’s disease in the local context is not accurately known.

“I hope our test will offer more accurate, rapid and quantitative results. Therefore, it will help farmers and vets make more informed decisions about the infection status of animals in order to control the disease more effectively within herds. I also hope it will generate more accurate data on the prevalence of Johne’s disease within Northern Ireland and paint a better picture of the problem.”