tuberculosis (TB) /t(y)o̅o̅bur′kyəlō″sis/ [L, tuber + Gk, osis, condition] , a chronic granulomatous infection caused by an acid-fast bacillus, Mycobacterium tuberculosis. It is generally transmitted by the inhalation or ingestion of infected droplets and usually affects the lungs, although infection of multiple organ systems occurs. Persons who are immunodeficient, such as those infected with human immunodeficiency virus, may have extrapulmonary tuberculosis. This includes disseminated tuberculosis, which involves multiple organs such as the liver, lung, spleen, bone marrow, and lymph nodes. Diagnosis is through biopsy, stain, sputum and gastric cultures, and x-ray studies. Central nervous system tuberculosis may occur as inflammation of the meninges or a mass lesion (tuberculoma). See also miliary tuberculosis, tuberculin test. ▪ OBSERVATIONS: Listlessness, vague chest pain, pleurisy, anorexia, fever, and weight loss are early symptoms of pulmonary tuberculosis. Night sweats, pulmonary hemorrhage, expectoration of purulent sputum, and dyspnea develop as the disease progresses. The lung tissues react to the bacillus by producing protective cells that engulf the disease organism, forming tubercles. Untreated, the tubercles enlarge and merge to form larger tubercles that undergo caseation, eventually sloughing off into the cavities of the lungs. Hemoptysis occurs as a result of cavitary spread. ▪ INTERVENTIONS: The bacillus is generally sensitive to isoniazid, pyrazinamide, paraaminosalicylic acid, streptomycin, rifampin, ethambutol, dihydrostreptomycin, ultraviolet radiation, and heat. A combination of drugs is prescribed, with regular tests of the function of the kidneys, liver, eyes, and ears to discover early signs of drug toxicity. This is particularly important because drug therapy will usually continue for up to 1 year. The person may be hospitalized for the first weeks of treatment to limit the possible spread of infection, to encourage rest and excellent nutrition, to ensure complete compliance with the prescribed drug regimen, and to observe for adverse drug effects. Samples of sputum are regularly examined. The disease is not infectious after the bacillus is no longer present in the sputum. Care of an outpatient includes continued medication, evaluation for adverse drug effects, sputum analyses, and encouragement to complete the long course of treatment. All contacts are tested periodically with purified protein derivative. People who are at increased risk of infection may be treated empirically, without a positive diagnosis having been made. BCG vaccination has been widely used worldwide but may not be effective at preventing tuberculosis. ▪ PATIENT CARE CONSIDERATIONS: Before discharge the patient is taught how to prevent the spread of the disease; the elements of good nutrition; the name, dose, action, and side effects of all medications prescribed; the need to take the drugs regularly; and how and where to get the next supply of drugs. Plans for follow-up care are discussed; they include date, time, and place of the next laboratory tests; referral to community nurses is made. The patient is reminded that a cough, weight loss, fever, night sweats, and hemoptysis are danger signals that are to be reported immediately.
