Scientists from Purdue University are using breakthrough molecular research and other new technologies to slash the diagnosis time of Johne's disease (paratuberculosis), the little known, usually fatal infection that causes US$1bn in US cattle industry losses annually.

Johne's disease is characterised by weight loss without loss of appetite, diarrhea, and finally wasting and death. The disease can attack all ruminants and scientists say it is closely related to the human Crohn's disease.

"It used to take us 12 to 16 weeks to get a final diagnosis. Now we can detect the organism as early as two weeks," said Ching Ching Wu, a microbiologist with Purdue and the Indiana Animal Disease Diagnostic Laboratory (IADDL).

Wu and her colleagues have developed new Molecular techniques and are using an automated incubation unit, called the ESP para-JEM system, which was developed by Trek Diagnostics Systems earlier this year.

Wu added: "Being able to test more samples allows us to know the extent of the illness' spread and to learn more about its workings."

According to the US Department of Agriculture (USDA), about 22% of US dairy herds (and about 24% of those in the Midwest) are infected with the intestinal illness. Furthermore, the USDA says at least 45% of US dairy producers don't know about the disease and testing for it is voluntary.

Thomas Conner, director of the Indiana State Board of Animal Health's Cattle and Ruminant Division, said that educating producers about Johne's disease and its control is a main priority. Although a vaccine exists to reduce the symptoms and prolong an animal's life, it does not prevent infection, Conner explained, adding: "Diagnosis is one of the biggest problems."

Johne's disease is spread via infected feed, water and colostrums, and females with high infection can pass it in utero to fetuses. Most animals are infected at less than six months of age, although symptoms don't appear for two years to five years.

Besides dairy cattle, other types of cattle, deer, elk, sheep, goats, antelope and bison also can fall victim. However, it is more prevalent in animals that are kept in confined conditions and relatively unusual in wildlife, Conner said. According to the USDA, some reports exist of the same bacteria infecting horses, pigs, chickens, rabbits, fox and non-human primates.