CHARACTERISTICS OF TUBERCULOSIS PATIENTS WHO GENERATE SECONDARY CASES

OBJECTIVE: To determine the characteristics of smear positive tubercul osis (TB) patients who generate secondary TB cases. METHODS:Those smea r positive TB patients detected by the Barcelona Tuberculosis Program between 1990-1993, and for whom contact studies had been performed, we re studied. We analyzed the predictive role of the variables: age, sex , intravenous drug use (IVDU), the presence of the acquired immune def iciency syndrome (AIDS), human immunodeficiency virus (HIV) infection, radiology pattern, district of residence, history of imprisonment, al coholism, smoking, history of TB, treatment compliance and the number of secondary cases generated. Statistical analysis was based on the lo gistic regression model, calculating the odds ratios (OR) with 95% con fidence intervals (CI). RESULTS: Of the 1079 patients studied, 78 (7.2 %) had generated only one secondary case, and 30 (2.8%) two or more. T he variables associated with generating two or more secondary cases we re: IVDU (P < 0.001; OR = 4.06; CI: 1.80-9.15), cavitary radiology pat tern (P = 0.002; OR = 3.69; CI: 1.62-8.43), and age (P = 0.016; OR = 0 .98; CI: 0.96-0.99). When we examined those who had generated one or m ore secondary cases, the following variables were significant: IVDU (P = 0.043; OR = 1.75; CI: 1.02-3.02), cavitary radiology pattern (P < 0 .001; OR = 3.07; CI: 1.98-4.77) and age (P < 0.001; OR = 0.98; CI: 0.9 7-0.99). CONCLUSION: The study of the contacts of smear positive TB pa tients allows us to detect an important number of secondary cases. You ng adults, those with cavitary radiology pattern, and IVDU are more li kely to generate secondary cases.