Paratuberculosis, also known as Johne's disease, is a chronic infectious disease that primarily affects ruminants, including cattle, sheep, goats, and deer. It is caused by a bacterium called Mycobacterium avium subspecies paratuberculosis (MAP), which primarily affects the intestines.
The disease is characterized by a granulomatous inflammation of the intestinal tract, leading to a progressive thickening of the walls and subsequent loss of function. The bacteria invade the intestinal lining, causing an inflammatory response that damages the cells and impairs the absorption of nutrients. This results in chronic, intermittent, and sometimes bloody diarrhea, leading to significant weight loss, reduced milk production, and eventual wasting.
Paratuberculosis is primarily transmitted through the oral-fecal route, commonly from contaminated feed, water, or from direct contact with infected animals. Calves and lambs can acquire the infection from their mothers through colostrum or contaminated udders. The bacteria have a long incubation period, often taking months to years before clinical signs become evident.
Diagnosing paratuberculosis can be challenging due to the disease's slow progression and intermittent shedding of bacteria. Various diagnostic tests, such as fecal culture, polymerase chain reaction (PCR), and serum antibody tests, can be used to detect the presence of the bacterium or the animal's immune response.
Preventing paratuberculosis primarily involves good management practices, including proper hygiene, biosecurity measures, and control of contaminated feed and water sources. Vaccination is available, although its effectiveness and implementation can vary between countries and specific livestock production systems.
Paratuberculosis poses a significant economic burden for livestock keepers due to reduced productivity, increased mortality, and trade restrictions. Additionally, there is concern about
