Tuberculosis

What is tuberculosis?

Tuberculosis (TB) is an infectious disease that primarily affects the lungs but can impact most other organ systems as well. TB is caused by the Mycobacterium tuberculosis complex, which consists of seven species and subspecies.

What are the risk factors for tuberculosis?

People who are at the highest risk of contracting TB have compromised immune systems. Approximately one third of all HIV patients are infected with TB and a quarter of all AIDS-related deaths are caused by the infection.

In addition to HIV infection, other types of immunosuppression are also associated with an increased risk of developing tuberculosis. Patients who are receiving corticosteroids, tumor necrosis factor-alpha antagonists, or immunosuppressants for other conditions, including organ transplant recipients, are more likely to progress to active disease if they have a latent infection. An elevated risk is also present in patients with clinical conditions affecting their immune status, such as:

• Hematologic malignancies.
• Diabetes.
• Endstage renal disease.
• Head and neck cancer.
• Low body weight.
• Malabsorption syndromes.

Some other factors that can increase risk include:

• Alcohol and drug abuse.
• Smoking.
• Homelessness.
• Institutionalization (people living in nursing homes or correctional facilities).

What are the symptoms of tuberculosis?

Children under the age of five and people infected with HIV are more likely to develop severe or miliary disease. HIV patients may be asymptomatic, have minimal symptoms, classic symptoms, or atypical symptoms.

Signs and symptoms of active TB include:

• Coughing that lasts three or more weeks.
• Coughing up blood.
• Chest pain, or pain with breathing or coughing.
• Unintentional weight loss.
• Fatigue.
• Fever.
• Night sweats.
• Chills.
• Loss of appetite.

How is tuberculosis diagnosed?

The clinical presentation of TB varies depending on age, immune status, presence of comorbidities, site of infection, and virulence of the TB bacillus. TB is considered a chronic illness, although it may present acutely. In the non-HIV-infected population, 85 percent of patients with active TB present with pulmonary disease.

The most commonly used diagnostic tool for tuberculosis is a simple skin test, though blood tests are becoming more commonplace. A small amount of a substance called PPD tuberculin is injected just below the skin of your inside forearm. You should feel only a slight needle prick.

Within 48 to 72 hours, a health care professional will check your arm for swelling at the injection site. A hard, raised red bump means you’re likely to have TB infection. The size of the bump determines whether the test results are significant.

How is tuberculosis treated?

The goals of tuberculosis treatment are to cure the individual and to prevent the transmission of Mycobacterium tuberculosis to others. Treatment may prevent late complications and death, and reduce the risk for relapse. Adequate therapy also reduces the risk of drug resistance occurring and spreading.

When should I contact my healthcare provider?

Schedule an appointment with your healthcare provider if you:

• Have a cough that lasts more than three weeks.
• Are coughing up blood.
• Feel tired all the time.
• Experience night sweats.
• Have a fever and/or chills.
• Unexpectedly lost weight.