paratuberculosis

• Paratuberculosis, also known as Johne's disease, is a chronic contagious disease of animals caused by Mycobacterium avium subsp. paratuberculosis (MAP).
• The disease was first described by Johne and Frothington in 1895 and the first reported case in sheep was in Bosnia in 1908.
• Paratuberculosis affects mainly domestic and wild ruminants worldwide and can also affect many non-ruminant animals like camels, wild rabbits, pigs, horses, birds, and other carnivores.
• Mycobacterium avium subsp. paratuberculosis is mainly transmitted through ingestion of contaminated feed or water with manure.
• Infection occurs commonly in young ruminants due to infected colostrum and milk of infected dams soon after birth because their resistance is not yet complete.
• Infections can also arise transplacentally.
• Herd growth or the acquisition of replacement carrier animals can add to disease transmission.
• Paratuberculosis is considered as an economic problem as it is present worldwide.
• It is important to inform herd owners that it takes at least five years to control paratuberculosis.
• For paratuberculosis, there are a few vaccine options, although their effectiveness varies.
• Replacement herds should come from herds considered to be disease-free, and before being introduced to the new herd, the replacements themselves should undergo testing.
• In young animals, vaccination is usually used to either postpone or maybe prevent infection.
• Management strategies should be implemented alongside supportive care that can help control the spread of the disease within a herd and improve overall herd health.
• Farms can also benefit from additional initiatives to reduce fecal contamination, such as boosting food and water troughs, using piped water instead of ponds, and harrowing regularly to disperse manure across pasture.
• Currently, there is no commercially available vaccine for paratuberculosis in the Philippines because of its price, limited market size and regulatory requirements.
• Vaccination thus does not eliminate the need for good management and sanitation.
• There should be strict hygiene and sanitation measures to prevent transmission between animals, such as regularly disinfecting equipment and isolating infected animals.
• Mycobacterium avium subsp. paratuberculosis (MAP) has been found in Crohn's disease patients and has been linked to various human disorders such as rheumatoid arthritis, Hashimoto's thyroiditis, Type 1 diabetes, multiple sclerosis, and autism.
• The sickness is a possible public health risk.
• In the intestinal wall and lymph nodes of sheep, goats, and deer, caseation foci with calcification can occasionally form.
• The primary method used is polymerase chain reaction (PCR), which is more sensitive and specific than serology.
• It is recommended to utilize a laboratory that has successfully completed a prof
• Diagnosis of paratuberculosis is based on clinical signs, postmortem lesions, and laboratory confirmation.
• Different lesions may be seen in infected animals depending on its severity.
• Emaciated carcasses may have moderate intestinal lesions.
• Histologically, the mucosa and submucosa of the gut exhibit a gradual accumulation of epithelioid macrophages and large cells, indicative of a widespread granulomatous enteritis.
• Paratuberculosis in ovine and caprine are observed within 2 to 4 years of age and the signs often occur soon after birth.
• Diarrhea in cattle can occur constantly or continuously.
• While diarrhea might not be observed in ruminants such as sheep, goats, and others as it is usually passed without tenesmus and it lacks blood, mucus, or epithelial debris.
• The colon and jejunum may be affected both by the lesions.
• It is rare that animals exposed to very small doses of bacteria at an early age, or those exposed at a later age, will exhibit clinical symptoms until they are significantly older than two years of age.
• Stress factors may accelerate the onset of clinical disease.
• These animals will become more alert, have high temperatures, thirst and appetite.
• Visible symptoms typically include serosal lymphangitis and the swelling of mesenteric and other regional lymph nodes.
• Because culture is more expensive and the organism grows slowly which takes around 2–4 months, PCR is preferred than culture for MAP detection.
• The distal small intestinal wall is usually diffusely thickened, with noticeable transverse folds and non-ulcerated mucosa.
• It is possible to see a decrease of pericardial and perirenal fat in more severe cachectic cases.
• In dairy cattle and goats, milk yield may drop or fail to reach expected levels.
• Weight loss will also occur resulting in changes in the coat of the animal and formation of submandibular edemas.
• If their sensitivity is approximately 45%, they can also be used to identify infection in clinically normal animals when it is in its later stages and shedding a significant amount of MAP.