Johne’s Disease develops slowly, so it may be several years after a cow has been infected that it begins to show symptoms of disease. However, symptoms can also be triggered by stress such as calving, when the cow’s immune response is suppressed. Johne’s is a ticking time bomb in the herd.
Johne’s Disease, along with bovine tuberculosis (bTB) and human tuberculosis, is caused by a strain of mycobacteria, a clever bacteria that can hide in the body.
PBD Biotech is investigating the application of its blood test, Actiphage®, to detecting mycobacterial diseases in both humans and animals and recent findings from a human trial have important implications for animal diagnostics.
TB detection priority for WHO
A quarter of the human population have latent TB, meaning they are infected but show no symptoms. A small number of those will progress to full infection, which is called incipient TB. If it were possible to easily identify people with incipient TB, these individuals could be targeted for preventative treatment, a top priority for the WHO.
Now, human trials of Actiphage have shown that there is a link between the presence of mycobacterial cells in the blood and incipient TB in humans. The study used imaging to provide clinical evidence of incipient TB, a technique that would be too costly for widespread use with humans or for animals.
Actiphage diagnostic for human TB
Evidence from this study shows that there is potential to use Actiphage as a blood test for screening a high-risk population for incipient TB, and it also offers an alternative to the current sputum test that is difficult for children and the vulnerable to use. The use of Actiphage as a diagnostic for human TB is currently being explored in a project in Zambia.
Breakthrough for animal diagnostics
The research is also a real breakthrough for animal diagnosis as it provides clinical evidence that detection of low levels of mycobacteria in the blood is an indication that the animal is infected and has the potential to develop disease. Conversely, if no mycobacteria is found then the cow is clear.
This provides further verification that Actiphage can provide a rapid yes/no test for Johne’s Disease, also known as MAP. Additionally, as the test directly detects the bacteria responsible rather than the animal’s immune response, it is more likely to give results on which actions can be based.
PBD Biotech has recently launched a Johne’s Disease testing service based on Actiphage. If you would like to discuss the service, which can test either blood or bulk milk, then do get in contact.