Drug-resistant Tuberculosis in an Urban Population Including Patients at Risk for Human Immunodeficiency Virus Infection

Abstract

In the past 5 yr, an increased incidence of tuberculosis has been noted in the United States. Simultaneously, the population infected with human immunodeficiency virus-type I (HIV-I) and the number of cases of acquired immunodeficiency syndrome (AIDS) have increased. Selected areas of the United States have also reported increases in the frequency of drug-resistant isolates of Mycobacterium tuberculosis. Because our institution serves a population in which tuberculosis, AIDS, and drug resistant isolates of M. tuberculosis are frequently encountered, we sought to better define interrelationships among these factors by retrospectively reviewing the demographic, clinical, bacteriologic, and radiologic data for all adult patients in whom M. tuberculosis was isolated from a culture of respiratory-tract secretions during a 1-year period (June 1, 1988 to May 31, 1989). Two hundred forty-six patients were thus identified; 66.5% were U.S. born blacks, and 62.6% were 17 to 40 yr of age. Risk factors for HIV infection were present in 106 patients. The overall resistance rate (one or more drugs) = 30.9%, with primary resistance = 22.6% (35 of 155) and secondary resistance = 49.2% (29 of 59). In addition, 12 resistant isolates were found in 32 patients whose prior treatment status was indeterminate. Of the resistant isolates, 56.6% (43 of 76) were multiply resistant. Isoniazid resistance was noted in 90.7% (69 of 76) and rifampin resistance was noted in 50% (38 of 76) of the resistant isolates. No significant differences in the overall frequency of resistance were noted in patients at risk for HIV infection compared with those without these risks.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk factors associated with drug-resistant Mycobacterium tuberculosis in Castilla-la-Mancha (Spain)

“…The 46% of patients previously treated for TB presented SR, a rate which is similar to other studies [3,4], but which is slightly higher than recent investigations in Spain [24,29]. This fact may be due to more exhaustive data collection or to more precise registration.…”

“…The age of the patients and previous history of hepatic cirrhosis were also independent risk factors in the presence of resistance to antituberculosis drugs. SCALCINI et al [30], in Haiti, described an increase in resistance with age, although other writers have not observed this relationship [2,4,16]. In our study, those patients who were 45 or more years of age presented a risk almost four times higher than those of less than 45 yrs, even adjusting for other potential risk factors.…”

“…KELLY et al [1] reported a PR rate of 6.9% between 1975 and 1982, inferior to the 8.6% of KOPANOFF et al [27]. Nonetheless, the Centers for Disease Control (CDC) reported an incidence of 13.4% in the first 3 months of 1991 [7], with 3.5% of PR to INH and R, superior to the 1.6% suggested by CHAWLA et al [4], and which continued through 1992 [23]. In New York, the rate of MDR-TB is 12.9%, with no differences compared to other states as far as foreign birth (immigration) or history of recurrent illness is concerned, although the number of patients who complete the treatment is inferior to the US average [28].…”

“…In the USA, however, the reported rate was 14.2% in 1991 [7] and 13.2% in 1992 [23], although the figure varies from one state to another. These differences are due, above all, to the number of immigrants living in each study area, and of HIV-positive patients [3,4,7,16,23].…”

“…Interest in the study of resistance to antituberculosis drugs has risen in recent years [1][2][3][4] due to an increase in tuberculosis (TB) coinciding with the appearance of the acquired immune deficiency syndrome (AIDS) [5,6]. Resistance to one or more first-line drugs increased in the USA from 6.9% in 1982 to 14.2% in 1991 [7], with an incidence of resistance to isoniazid (INH) and rifampin (R) of 3.5%.…”