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We offered directly supervised isoniazid preventive therapy to middle-aged and elderly men who were exposed to tuberculosis during an outbreak of cases at a homeless shelter. Isoniazid, 900 mg, was administered twice weekly to men at the shelter and at the downtown Public Health Clinic. We report on compliance and adverse reactions associated with this preventive regimen. Isoniazid preventive therapy was offered to 64 men. Forty-seven men (73%) began therapy, and 23 of them (49%) completed the 6- to 12-month regimen. Men who failed to complete isoniazid therapy received a median of 11 biweekly doses (range, 1 to 41 doses) over a median of 9 wk (range, 3 to 37 wk). The most common reason for incomplete treatment was that the men no longer frequented the shelter. One hepatotoxic reaction occurred, for a 2.1% cumulative incidence among all men who started therapy and a 3.7% cumulative incidence among the 27 known alcoholic men who began therapy. In addition, we sought to identify personal characteristics of the men that might be associated with noncompliance. Out-of-state location of personal contacts in case of emergency was strongly associated with poor compliance. These data provide some assurance that directly supervised isoniazid preventive therapy may be offered safely to sheltered elderly men with a high prevalence of alcoholism. Further improvements in compliance with isoniazid preventive therapy in homeless populations may depend on the development of a therapeutic regimen of only 2 to 3 months duration.

An outbreak of tuberculosis at a shelter for homeless men was studied in detail to further the understanding of the epidemiology of tuberculosis in this setting. The shelter provides evening accommodations for men aged 50 yr and older. The capacity is approximately 200 clients, and the client pool is approximately 1,000 men/yr. During a 6-wk period in December 1986 and January 1987, seven cases of tuberculosis were diagnosed in shelter clients. Nine cases were reported in clients during the preceding 12 months, and four cases in the year previous to that. The majority of outbreak cases were pulmonary tuberculosis, sputum smear positive. Drug resistance was rare. Phage typing of 15 Mycobacterium tuberculosis isolates revealed one predominant type and four other types. The goals of the control plan (and the steps taken to achieve them) were to render known infectious cases noninfectious (directly observed therapy); to find undiagnosed infectious cases (repetitive mass screenings); to protect exposed clients (repetitive tuberculin skin testing and isoniazid preventive therapy); and to make the shelter environment safe (exclude infectious, noncompliant clients and improve the shelter's ventilation system). Implementation of this plan rapidly terminated the outbreak; following the first mass screening in January 1987, at which six asymptomatic cases were detected, only five additional cases occurred in shelter clients during a 2-yr period of follow-up. The investigation suggested that the outbreak evolved during 1986 as a result of the presence at the shelter of an increasing number of men with undiagnosed infectious pulmonary tuberculosis.(ABSTRACT TRUNCATED AT 250 WORDS)

The outcome of isoniazid chemoprophylaxis for tuberculosis was assessed in refugees from Southeast Asia. From July 1979 through June 1982, 2,795 tuberculin-positive refugees were prescribed isoniazid chemoprophylaxis at the time of their resettlement in King County, Washington. Through December 1983, 19 cases of active tuberculosis had arisen in those refugees. The annual incidence varied between 2.04 and 2.86 cases per 1,000 receiving treatment during the 4 yr after initiation of chemoprophylaxis (cumulative incidence, 9.66 per 1,000). Seven of the cases of tuberculosis occurring after isoniazid chemoprophylaxis were pulmonary, 1 was pulmonary and extrapulmonary (lymphatic), and 11 were extrapulmonary alone (lymphatic, 6 cases; pleural, 4 cases; soft tissue, 1 case). Fifteen of the 19 cases were culture positive, among which 8 M. tuberculosis isolates were susceptible to isoniazid and 7 were resistant. A case-control analysis showed that poor compliance, defined as taking isoniazid for 3 months or less, was associated with a sixfold increase in risk for subsequent isoniazid-susceptible tuberculosis but with no increased risk for subsequent isoniazid-resistant disease. Thus, active tuberculosis continued to occur with a low but relatively constant incidence after prescription of isoniazid chemoprophylaxis to Southeast Asian refugees. In this setting, poor compliance with chemoprophylaxis predisposed to isoniazid-susceptible, but not to isoniazid-resistant tuberculosis. There is a need to improve the approach to prevention of tuberculosis in Southeast Asian refugees.

Because of possible deficiencies in the evaluation, based on symptoms and chest roentgenogram review, of new immigrants classified during the visa application process as tuberculosis suspects, a prospective (cohort) and a retrospective (case control) study were done to test the usefulness of routinely obtaining sputum specimens for culture in that setting. In the prospective study, 249 consecutive classified immigrants who were considered on the basis of clinical and roentgenographic findings to have nonprogressive tuberculosis submitted at least two sputums for culture: 13 (5.2%) had at least one culture positive for M. tuberculosis. Immigrants younger than 50 yr of age and refugees from Kampuchea and Laos had a fivefold to tenfold elevated risk of having a positive sputum culture. The cost per case detected of obtaining and processing sputum cultures was estimated to be +1,996 to +2,994. In the case-control study, 37 classified immigrants evaluated from 1981 through 1986 who had sputum cultures positive for M. tuberculosis even though they fulfilled clinical and roentgenographic criteria for nonprogressive tuberculosis served as control subjects. Several demographic, clinical, and roentgenographic factors were associated with an increased risk of being culture-positive: age younger than 50 yr, a positive tuberculin test, report of a cough, and a cavitary lesion on chest roentgenogram. The history of prior receipt of antituberculosis drugs was associated with having a negative culture, including a marked dose-response effect.

Morbidity caused by tuberculosis was determined in a cohort of 9,328 refugees from Southeast Asia during the first 5 yr after their immigration to the United States. The entire cohort was screened at the time of entry, and isoniazid preventive therapy was offered according to ATS-CDC guidelines. During the period of study, 25 cases of tuberculosis were reported from the cohort. The 5-yr cumulative incidence of tuberculosis (26.8 cases per 10,000 in the entire cohort) was greatest in tuberculin-positive refugees who had abnormal screening chest roentgenograms (324.3 cases per 10,000) and least in those with nonsignificant tuberculin reactions (5.0 cases per 10,000). The annual incidence of tuberculosis in the cohort decreased from an estimated 30.6 cases per 10,000 at the time of immigration to less than 5 cases per 10,000 during the fourth and fifth years. The prevalence of resistance to isoniazid was greater in culture-positive cases arising after immigration (7 of 22, 32%) than in those diagnosed at the time of immigration (5 of 36, 14%), probably because of a reduction in isoniazid-susceptible cases by isoniazid preventive therapy. Currently recommended screening and preventive services may be favorably impacting tuberculosis morbidity in newly arriving refugees from Southeast Asia.