It is an infection caused by a group of bacteria collectively known as non-tuberculous mycobacteria (NTM). Majority of infections by NTM involve the lung but involvement of other parts of the body such as the lymph nodes, skin and soft tissue, bone and joint are also seen. Hospital acquired infections from NTM such as surgical wound infections and bloodstream infections are also increasingly recognised.
Similar to tuberculosis, NTM infections generally progress in a slower, gradual manner compared to the usual bacterial infections. NTM lung infection typically presents with chronic symptoms of prolonged cough, breathlessness, fatigue and non-specific chest pains. Patients with NTM lung infection commonly have associated chronic lung conditions (e.g bronchiectasis) that causes dilation of the airways and permanent scarring of the lungs. In instances where it involves blood vessels in the lungs, it may cause patient to cough out blood, called hemoptysis in medical terms. Constitutional symptoms such as prolonged fevers and weight loss are also common symptoms.
There are no established measures that would prevent this infection. NTM organisms are readily found in our environment and could even be found on our bodies, such as in the airways leading to the lungs. In majority of cases, this situation would not result in infection. Rather, NTM infection usually happens in predisposed patients (see below), such as those with poor immunity or underlying chronic lung diseases. In these cases, the organism is able to overcome the patient’s body defences resulting in clinical infection.