Bovine Tuberculosis
Dr Rashmi Singh, Dr Aakanksha Chaudhary, Dr Bhavana Rathore
Post Graduate Institute of Veterinary Education and Research (PGIVER), Jaipur, RAJUVAS, Bikaner
https://www.pashudhanpraharee.com/bovine-tuberculosis/
Bovine tuberculosis (BTB) is an infectious, chronic and contagious disease of livestock, wildlife and humans. The disease in different species of animals and man is caused by different types of Mycobacterium. Bovine tuberculosis is caused by M. bovis but cattle may get infected with human type of Mycobacterium also. The name Tuberculosis comes from the nodules, called ‘tubercles’, which form in the lymph nodes of affected animals. This disease causes great economic loss and significant public health risk in several underdeveloped countries in the world. The Office International des Epizooties has listed tuberculosis as a list B disease. It is also of significance in terms of international trade of animal and animal products. Bovine tuberculosis is a zoonotic disease and is major cause of human infection in underdeveloped countries but is not generally regarded as significant public health hazard in developed nations.
A WHO fact sheet dated March 2010 on tuberculosis stated that overall, one third of the world’s population (over 2 billion) is currently infected with the TB bacillus. According to it, every second, someone in the world is newly infected with TB bacilli and 1 in every 10 of these newly infected people will become sick or infectious later in life. The economic burden of TB on India is huge and is a great loss in terms of lives, money and workdays. It is estimated that about 170 million workdays are lost annually in the country due to disease. The annual income cost of tuberculosis to the Indian economy is about 3 billion US dollar. Unless control efforts are stepped up, tuberculosis will kill 28 million people between 2015 and 2030, and cost global economy almost 1trillion US dollar.
In cattle the disease hampers the economic aspect also. There is loss of milk production, reduction in reproductive performance, loss of meat production and loss of body weight.
The disease is chronic in nature therefore it spreads gradually without being noticed. The infected animals may not show clinical signs in initial stage but afterwards infected animals loose body weight slowly but continuously in spite of provision of sufficient nutrition.
Respiratory system most commonly infected. There is dyspnoea, increase rate of respiration and deep, persistent, painful, dry coughing is seen. Involvement of digestive system, reproductive system and nervous system also seen. Acute milliary tuberculosis is characterized by difficult breathing, pulmonary symptoms, high fever, diarrhea, rapid emaciation and death.
For diagnosis of BTB the intradermal tuberculin test is the official test for bovine tuberculosis in most of the countries and it has been used for routine field detection of infected animals. However, many limitations have been reported to the SID tuberculin test for the diagnosis of BTB, other diagnostic tests like Enzyme Linked Immuno Sorbent Assay (ELISA), an immune chromatographic assay (ICGA) and a latex bead agglutination assay (LBAA) have been evaluated for serodiagnosis of bovine tuberculosis with high sensitivity and specificity to overcome the limitations of tuberculin test.
For treatment of new cases of pulmonary or extrapulmonary TB, WHO recommends a standardized regimen consisting of two phases. The initial (intensive) phase uses four drugs rifampicin, isoniazid, pyrazinamide and ethambutol administered for two months. This is followed by a continuation phase with two drugs rifampicin and isoniazid for four months or, exceptionally, with two drugs isoniazid and ethambutol for six months when adherence to treatment with rifampicin cannot be ensured.
Treatment of sick animals are generally attempted same as of human treatment. Drugs used in human TB like isoniazid and para aminosalicyclic acid and streptomycin sulphate have been used as chemo therapeutic agents in animals. Treatment of infected animals is rarely attempted because of the high cost, lengthy time and the larger goal of eliminating the disease.
https://www.cdc.gov/tb/publications/factsheets/general/mbovis.pdf
