Tuberculosis is one of the world’s most widespread and deadly illnesses. M tuberculosis, the organism that causes tuberculosis infection and disease, infects one-third of the world’s population. In 2012, there were 8.6 million new cases of tuberculosis worldwide with 1.3 million people dying of the disease. In the United States, an estimated 11 million people are infected with M tuberculosis. Tuberculosis occurs disproportionately among disadvantaged populations such as the malnourished, homeless, and those living in overcrowded and substandard housing. There is an increased occurrence of tuberculosis among HIV-positive individuals.
Table 9–14. Characteristics of antituberculous drugs.
Symptoms and Signs
The patient with pulmonary tuberculosis typically presents with slowly progressive constitutional symptoms of, malaise, anorexia, weight loss, fever, and night sweats. Chronic cough is the most common pulmonary symptom. It may be dry at first but typically becomes productive of purulent sputum as the disease progresses. Blood-streaked sputum is common, but significant hemoptysis is rarely a presenting symptom; life-threatening hemoptysis may occur in advanced disease. Dyspnea is unusual unless there is extensive disease. Rarely, the patient is asymptomatic. On physical examination, the patient appears chronically ill and malnourished. On chest examination, there are no physical findings specific for tuberculosis infection. The examination may be normal or may reveal classic findings such as posttussive apical rales.