Johne’s Disease

One in three UK herds include carriers of Johne’s Disease, also known as MAP, a chronic wasting disease with no treatment and no compensation, that can lie undetected until animals are over three years old.

Actiphage by detecting live mycobacteria enables disease management through the removal of these animals from the herd or prior to movement. 

Johne's disease lies dormant in herd

Johne's Disease is transmitted to the calf, although older animals can be infected by the faecal oral route, so the risk comes from contaminated calfing areas and sharing milk to feed calves. It can remain dormant in the animal until it is triggered by stress or an other infection.

The disease can have a serious economic impact through

• Reduced milk yields and poor fertility
• Loss of body condition
• Increasing vulnerability to mastitis
• Risk of contaminated milk

A pre-breeding test would be good way to help control Johne's. Preventing positive animals from being bred would reduce the spread of bacteria in calving areas and prevent the infection of calves through milk.

Detect carriers before they spread disease

Actiphage detects live mycobacteria in blood or milk samples, unlike the antibody test, which measures the immune response to the disease. This means it can identify animals with Johne's Disease before they become infectious and start to shed the bacteria.

So, for the first time Actiphage enables farmers to introduce a disease management strategy to eradicate Johne’s Disease:

• Pre-breeding test - test the cows before breeding so infected animals are prevented from breeding
• Pre-movement test - a blood test of new stock will identify infected animals before you introduce them into your herd
• Early identification - Actiphage can detect low numbers of mycobacteria in the blood of calves from 6 weeks¹ and young animals. Enabling infected animals to be removed from the herd before they infect others
• Prevent transmission - identifying and isolating animals with the disease before they shed in faeces will reduce the risk to adult animals.
• Herd screening - the bulk milk test can provide an early indication of a problem in the herd, or provide confidence that milk is free of MAP.
• Potential DIVA test - a vaccine is available for Johne’s which reduces clinical disease but will not prevent transmission. Unlike the current test, Actiphage can distinguish between live infection and vaccinated animals.

Testing service for blood and milk

Actiphage is a simple test for blood or bulk milk that can be used to screen the herd to detect infected animals. It enables management of the herd to reduce the economic loss and to provide quality assurance to retail customers and consumers.

• Avoid introducing infected animals into your herd
• Manage carriers before they shed the disease and infect others
• Prevent infected animals from calving
• Test bulk milk for quality assurance

If you would like more information about Actiphage do get in contact. (note the commercial Johne's Disease Testing service was suspended in January 2023 but work continues with research partners.)

1. Pelletier C. et al, 'Detection of active infection of new-born calves by Mycobacterium avium subsp. paratuberculosis (MAP) in first days of life', Abstract presented at the European Association of Veterinary Laboratory Diagnosticians Congress (2018)