Tuberculosis is not the only mycobacteria that can infect humans. While nontuberculous mycobacteria are common in soil and water, they are not as likely to infect someone as Mycobacterium tuberculosis is. However, to the elderly and immunocompromised these bacteria can be cause for concern. Nontuberculous mycobacteria form biofilms, allowing them to survive in potable water systems and making them difficult to eradicate with common decontamination practices such as chlorination. M. avium complex (MAC), the two closely related species of M. avium and M. intracellulare, is most often the culprit behind human infection, but M. kansasii, M. xenopi, M. marinum, M. ulcerans, M. fortuitum, M. abscessus, and M. chelonae can also cause infections. These infections most frequently affect the lungs and involve MAC, but may be caused by M. kanasii, M. xenopi, or M. abscessus. Occasionally lymph nodes, bones, joints, wounds, and the skin may be affected by the infection. These infections are also commonly resistant to anti-TB drugs, except for the M. kanasii and M. xenopi strains. Nontuberculous mycobacteria
NTM Causing Pulmonary disease: The typical patient is a middle-aged or elderly woman without known lung abnormalities, but suffering from bronchiectasis, scoliosis, pectus excavatum, or mitral valve prolapse. MAC can also cause pulmonary disease in middle-aged or older white men with previous lung problems. If MAC causes bronchiectasis or vice versa is not always clear. In older, thin women with chronic nonproductive cough, this syndrome is frequently referred to as Lady Windermere syndrome. This syndrome is increasing in frequency for unknown reasons. Cough, expectoration, fatigue, weight loss, and low-grade fever are common symptoms. The infection may progress slowly or seem stable for long periods of time. Because of drug resistance, susceptibility testing can be very helpful. However, such testing can only be done in highly specialized laboratories. To effectively treat these infections, multiple medications are taken daily for months, usually between 12 to 18 months, or until cultures have been negative for 12 months.
NTM Causing Lemphadenitis: Typically affects children between 1 and 5 years of age. MAC and M. scrofulaceum are the most common culprits causing chronic submaxillary and submandibular cervical lymphadenitis. Treatment is excision and chemotherapy is usually not required.
NTM Causing Cutaneous disease: M. marinum, M. ulcerans, and M. kansasii can cause lesions and reddish bumps, enlarging and turning purple, on the upper extremities or knees by coming into contact with infected water. This may heal spontaneously or may require treatment. In rural tropical and subtropical countries, M. ulcerans can cause Buruli ulder. This starts as a painless subcutaneous nodule, a large painless area of induration, or a diffuse painless swelling or the legs, arms, or face. However, as the infection progresses it will cause extensive destruction or the skin and soft tissue.
NTM and Wounds: M. fortuitum complex, M. Chelonae, M. abscessus complex are all rapidly growing. Use of contaminated injection solution, wound contamination with nonsterile water, use of contaminated instruments, or implantation or contaminated devices can cause serious infections. Treatment usually involves extensive debridement and removal of the foreign material, as well as medications lasting an average of 24 months.