Differentiation of tuberculous from nontuberculous cavitary lung disease.

Tuberculous and nontuberculous cavitary lung disease is often initially misdiagnosed, delaying therapy. To identify findings which might help avoid such delays, we performed a retrospective review of all patients admitted to two community hospitals over a 6-year period for infectious cavitary disease of the upper lobe or apical segment of the lower lobe. 10 patients with tuberculosis and 16 with nontuberculous infections were identified. Delays in initiating therapy were common to both. Most signs and symptoms were nonspecific. The mean duration of symptoms was greater in tuberculosis (72 days) compared to nontuberculous infections (18 days). Putrid sputum was found only in nontuberculous infections (11/16). Roentgenographic features of fibronodular infiltration and atelectasis occurred only in tuberculosis. Air fluid levels were seen only in nontuberculous disease (10/16). Leukocytosis with immature neutrophils was found only in patients with nontuberculous cavities. We conclude that the previously described clinical, laboratory, and roentgenographic features may be useful in correctly diagnosing infectious cavitary lung disease.

High rate of tuberculin conversion in Indochinese refugees.

From January 1979 through December 1980, a total of 664 Indochinese refugees were screened for tuberculosis in Monroe County, New York; 307 (46%) had positive 5-tuberculin unit PPD Mantoux tests. When 217 refugees with initially negative tests were retested at 60 days, 94 (43%) had converted from a negative to a positive test. Although none of the converters had evidence of active tuberculosis disease, 90 (96%) were given isoniazid preventive therapy. This conversion phenomenon has continued over time, discounting an effect of local, national, or international policy changes. The conversions do not seem to be a function of antigen, tester, or reader; criteria for testing, retesting, or reading; home country, camp country, or length of time in camp; or history of prior BCG vaccination, tuberculosis, or immunization exposure, current illness, or testing intervals since arrival in the United States and subsequent testing. Further studies to evaluate boosting or anergy are in progress to assess this potential public health problem.