TB and Nontuberculous Lung Infections
Mycobacterial lung infections are caused by a group of bacteria, mycobacteria, that includes the causative-agents of tuberculosis (TB) and leprosy.
There are also nontuberculous (NTM) mycobacteria, ubiquitous in soil, water, food, on the surfaces of many plants and within buildings, particularly within water pipes. Usually these bacteria are harmless to people but for unknown reasons, NTM lung infections are becoming more common in the developed world, including the United States, particularly in the Southwest (including southern California), Southeast and Hawaii.
Those at greater risk of NTM lung infections include:
- Post-menopausal women
- Those with a compromised immune system
- Those with lung damage from another condition such as chronic bronchitis, emphysema or
Though the prevalence of NTM infections is rising, these infections remain relatively rare, occurring in about 2-15 out of 100,000 people in America.
Because of this, many primary care physicians may not be familiar with the condition and people with a chronic cough caused by an NTM infection may go undiagnosed for a year or sometimes more.
Further complicating the diagnostic process is the fact that standard TB tests do not distinguish between TB and NTM germs. NTM infections, however, are not contagious.
UC San Diego Health offers newer diagnostic testing needed to distinguish TB and NTM lung infections. If a NTM infection is present, we will also identify the specific type of NTM, a process critical for determining which antimicrobial agents to use, or if treatment is even necessary or advised.
The diagnostics may include:
- Blood and sputum tests to identify the specific type of bacteria present in the lungs
- CT scans to image the lungs
- Bronchoscopy to view the lung’s airways
NTM lung infections may be resistant or hard to treat with antibiotics. As a result, patients may need to use several antibiotics, for up to years. Since many of these medications have side effects, close monitoring is important.
NTM infections that have spread beyond the lungs may need to be treated with chemotherapy. Surgery may also, in severe and rare instances, be performed.
TB was rare in the United States until the emergence of HIV in the 1980s. The virus weakens a person’s immune system making them less able to fight off germs, including TB and NTM.
People with HIV and a lung infection are treated at UC San Diego Health’s
Owen Clinic for specialty HIV care.