The importance of Mycobacterium bovis as a zoonosis

Mycobacterium bovis and closely associated acid-fast bacilli cause disease in humans. Epidemiologic investigations reveal that the organism may be ingested or inhaled. Extra pulmonary lesions may occur associated to the consumption of infected milk, even though with the practice of boiling milk, and the growth of milk pasteurization plants all over the world, the digestive route of infection became less important. On the other hand, airborne infection continues to occur among meat industry and slaughterhouse workers, in regions where the infection is still prevalent in cattle. Evidence of person to person transmission is rare. Main causes of concern related to M. bovis in industrialized countries are: epizootics in domesticated and wild mammals and latent infection in immigrants. Although multidrug-resistant (MDR) strains of M. bovis have been identified, case reports reveal that anti-tuberculosis drugs routinely used to treat Mycobacterium tuberculosis-infected patients are effective when properly administered.