Transmission of Mycobacterium tuberculosis from tuberculosis patients with HIV infection or AIDS.

Contacts exposed to tuberculosis patients with acquired immunodeficiency syndrome (AIDS) or human immunodeficiency virus (HIV) infection were compared with contacts of HIV-negative patients for evidence of Mycobacterium tuberculosis transmission, based on a review of records of tuberculin skin tests administered during routine health department follow-up investigations in Miami/Dade County, Florida, from 1985 through 1989. After an adjusted analysis designed to balance background prevalence, tuberculin positivity was 42.0% in 2,158 contacts of HIV-negative patients compared with 28.6% and 31.3% in 363 contacts of HIV-infected patients and 732 contacts of AIDS patients, respectively. Similar results were observed in a subset of 5- to 14-year-old contacts of United States-born black or white tuberculosis patients chosen to minimize the possibility of false-negative tuberculin tests in contacts due to undiagnosed HIV infection. Analysis of contacts as sets showed a more than expected number of sets with none or all contacts infected, but this did not differ by HIV/AIDS group. In this study, tuberculosis patients with AIDS or HIV infection were less infectious to their contacts and, in this community, exposed fewer contacts than HIV-negative tuberculosis patients.

Tuberculosis in health care workers at a hospital with an outbreak of multidrug-resistant Mycobacterium tuberculosis.

OBJECTIVE: Investigate reports of tuberculosis in health care workers employed at a hospital with an outbreak of multidrug-resistant Mycobacterium tuberculosis. DESIGN: Case series of tuberculosis in health care workers, January 1, 1989, through May 31, 1992. Antimicrobial susceptibility testing and restriction fragment length polymorphism analysis of M tuberculosis isolates. Longitudinal analysis of cumulative tuberculin skin test surveillance data. Assessment of infection control. The patients consisted of 361 health care workers who had either serial tuberculin skin tests or tuberculosis. RESULTS: Six health care workers, the largest number linked to one multidrug-resistant tuberculosis outbreak, had disease due to M tuberculosis that matched the outbreak strain from hospitalized patients. The two who were seropositive for human immunodeficiency virus died, one of tuberculous meningitis and the other of multiple causes including tuberculosis. The estimated risk of a skin test conversion was positively associated with time and increased by a factor of 8.3 (1979 to 1992). In 1992 the annual risk for workers in the lowest exposure occupational group was 2.4%. In comparison, nurses and housekeepers had relative risks of 8.0 (95% confidence interval, 3.2 to 20.3) and 9.4 (95% confidence interval, 2.7 to 32.3), respectively. Laboratory workers had a relative risk of 4.2 (95% confidence interval, 1.1 to 15.5). Tuberculosis admissions increased, but the hospital had inadequate ventilation to isolate tuberculosis patients effectively. There were lapses in infection control practices. CONCLUSIONS: Health care workers who were exposed during a hospital outbreak of multidrug-resistant tuberculosis had occupationally acquired active disease. The human immunodeficiency virus-infected health care workers with tuberculosis had severe disease and died. The risk of skin test conversion increased during the study period, and higher exposure occupations had elevated risk. Effective infection control is essential to prevent the transmission of tuberculosis to health care workers.

Nosocomial tuberculosis: an outbreak of a strain resistant to seven drugs.

OBJECTIVE: To evaluate nosocomial transmission of multidrug-resistant (MDR) tuberculosis (TB). DESIGN: Outbreak investigation: review of infection control practices and skin test results of healthcare workers (HCWs); medical records of hospitalized TB patients and mycobacteriology reports; submission of specimens for restriction fragment length polymorphism (RFLP) typing; and an assessment of the air-handling system. SETTING: A teaching hospital in upstate New York. RESULTS: Skin-test conversions occurred among 46 (6.6%) of 696 HCWs tested from August through October 1991. Rates were highest on two units (29% and 20%); HCWs primarily assigned to these units had a higher risk for conversion compared with HCWs tested following previous incidents of exposure to TB (relative risk [RR] = 53.4, 95% confidence interval [CI95] = 6.9 to 411.1; and RR = 37.4, CI95 = 5.0 to 277.3, respectively). The likely source patient was the only TB patient hospitalized on both units during the probable exposure period. This patient appeared clinically infectious, was associated with a higher risk of conversion among HCWs providing direct care (RR = 2.37; CI95 = 1.05 to 5.34), and was a prison inmate with TB resistant to seven antituberculosis agents. The MDR-TB strain isolated from this patient also was isolated from other inmate and noninmate patients, and a prison correctional officer exposed in the hospital. Mycobacterium tuberculosis isolates from all of these patients had matching RFLP patterns. Infection control practices closely followed established guidelines; however, several rooms housing TB patients had marginal negative pressure with variable numbers of air changes per hour, and directional airflow was disrupted easily. CONCLUSIONS: These data strongly suggest nosocomial transmission of MDR-TB to HCWs, patients, and a prison correctional officer working in the hospital. Factors contributing to transmission apparently included prolonged infectiousness of the likely source patient and inadequate environmental controls. Continued urgent attention to TB infection control is needed.

Respirators, recommendations, and regulations: the controversy surrounding protection of health care workers from tuberculosis.

Recent nosocomial outbreaks of tuberculosis have increased concern about the occupational acquisition of tuberculosis by health care workers. The Centers for Disease Control and Prevention (CDC), Department of Health and Human Services, and the Occupational Safety and Health Administration, Department of Labor, have issued recommendations and regulations in an effort to decrease health care workers' risk for exposure to patients with infectious tuberculosis. Within the CDC, the National Center for Infectious Diseases, the National Center for Prevention Services, and the National Institute for Occupational Safety and Health collaborated to produce the 1994 Guidelines for Preventing the Transmission of Tuberculosis in Health-Care Facilities. As stated in the Draft Guidelines, the major components of health care worker protection from Mycobacterium tuberculosis infection include administration or source controls, engineering controls, and respiratory protective devices. We review the evolution of the seemingly conflicting recommendations for respiratory protective devices made by these Centers of the CDC and explain how the recommendations in the current CDC Guidelines were reached.

Multidrug-resistant tuberculosis in the New York State prison system, 1990-1991.

Three epidemiologically linked multidrug-resistant (MDR) tuberculosis (TB) outbreaks in 1990-1991 involving New York State (NYS) inmates suggested MDR-TB was widespread in NYS prisons. Inmate lists were linked to 1990-1992 TB registries, medical records were reviewed, and movement histories for inmates with MDR-TB were examined within and between prisons and hospitals. In 1990-1991, 171 inmates were diagnosed with TB. This rate (156.2/100,000) was significantly higher than the 1990-1991 US rate (10.4/100,000) and the 1986 rate among NYS inmates (105.5/100,000). Of 171 cases, 155 were cultured-confirmed; 37 (32%) of 116 with drug susceptibilities determined had MDR-TB. Two other inmates with TB before 1990 were diagnosed with MDR-TB in 1990-1991. Of 39 inmates with MDR-TB, 38 (97%) were infected with the human immunodeficiency virus and 34 (87%) have died. These 39 lived in 23 of the 68 NYS prisons while potentially infectious; 12 were transferred through 20 prisons while ill with MDR-TB. Policies of correctional systems on infection control and inmate transfers need to be reevaluated to prevent spread of TB.

Outbreak of multi-drug-resistant tuberculosis in a New York State prison, 1991.

In the summer of 1991, four inmates from prison A in Upstate New York died of multi-drug-resistant tuberculosis. To determine the extent of resistant tuberculosis at prison A and transmission patterns, the authors interviewed staff and reviewed medical records and inmate movement histories. Contact investigation results were examined to determine tuberculin skin test conversions and to estimate risk of infection and disease for inmates who were seropositive for human immunodeficiency virus (HIV). Eight HIV-positive inmates and one HIV-negative guard, who was immunocompromised with cancer, had multi-drug-resistant tuberculosis. Eight died, a median of 28 days after the first culture-positive specimen was collected. All isolates had identical seven-drug resistance and DNA fingerprint patterns. Of exposed inmates, 92 out of 306 (30%) had skin test conversions. HIV infection was not associated with becoming infected with drug-resistant tuberculosis (active disease or skin test conversion), but once infected, HIV-positive inmates were significantly more likely to develop disease than were HIV-negative inmates (p < 0.001). The source case transferred to prison A in February 1991, was ill with undiagnosed multi-drug-resistant tuberculosis, refused medical care, and lived in the general prison population, where he transmitted the disease to other inmates. Lapses in infection control and laboratory delays contributed to this outbreak. Prisons should fully implement infection control guidelines to prevent tuberculosis transmission.

Nosocomial outbreak of tuberculosis in a renal transplant unit: application of a new technique for restriction fragment length polymorphism analysis of Mycobacterium tuberculosis isolates.

From January 1990 through February 1991, tuberculosis (TB) developed in 10 renal transplant (RT) patients at one hospital; 5 patients died. Possible nosocomial transmission was investigated. Mycobacterium tuberculosis isolates were compared by restriction fragment length polymorphism (RFLP) by a polymerase chain reaction method. The source case occurred in an RT patient (source) who had posttransplant exposure to TB at another hospital. The source patient was rehospitalized on the RT unit; diagnosis of TB and thus isolation precautions were delayed. Epidemiologic and RFLP analysis showed transmission from the source to 5 RT patients and 1 human immunodeficiency virus-infected patient. M. tuberculosis isolates from 4 RT patients had other RFLP patterns. The median incubation period for TB in RT patients was 7.5 weeks (range, 5-11). Bronchoscopy and intubation of the source patient and inadequate ventilation on the RT unit possibly increased transmission. Early detection of TB and effective isolation are essential to prevent nosocomial transmission.

Tuberculosis symposium: emerging problems and promise.

Between 1985 and 1991, 39,000 cases of tuberculosis occurred in excess of those expected based on previous trends. Immigration from high-prevalence countries, coinfection with human immunodeficiency virus (HIV), and outbreaks in congregative facilities are most responsible for the increase. Coincident with the increase in tuberculosis, outbreaks of multidrug resistant (MDR) tuberculosis have occurred. Clinical and epidemiologic data support nosocomial transmission. MDR tuberculosis occurred late in the course of HIV infection and was refractory to treatment. Compounding the problems of rising incidence and increasing resistance was the sudden recognition of shortages of antituberculous drugs. The problems currently posed by tuberculosis require new approaches to diagnosis and rapid sensitivity testing as well as assuring an adequate supply of licensed drugs and development of new drugs. A number of steps have been taken by governmental agencies to assure that the challenge is met.

Epidemiology of extrapulmonary tuberculosis among persons with AIDS in the United States.

AIDS surveillance data reported to the Centers for Disease Control from January 1981 through December 1991 were analyzed in a study characterizing persons with human immunodeficiency virus (HIV) infection and extrapulmonary tuberculosis (EPTB) in the United States. Among 206,392 persons reported to have AIDS, 4,751 (2.3%) were also reported to have EPTB; of these cases, 4,257 (90%) were reported after September 1987, when the case definition for AIDS was revised to include EPTB. Seventy-six percent of persons in whom AIDS and EPTB were reported after this revision were born in the United States; among these persons, the annual percentage with EPTB in 1988-1991 ranged from 2.3% to 2.5%. The South and the Northeast accounted for 73% of EPTB cases in U.S.-born persons. U.S.-born non-Hispanic blacks (odds ratio [OR], 3.3) and U.S.-born Hispanics (OR, 2.1) were more likely than U.S.-born non-Hispanic whites to be reported as having EPTB. Intravenous drug users were at higher risk (OR, 2.9) than men who reported having had sex with other men. With the resurgence of tuberculosis and the continued expansion of the HIV epidemic, these data provide a useful basis for the targeting of efforts to control tuberculosis and to prevent HIV infection.

The emergence of drug-resistant tuberculosis in New York City.

BACKGROUND: In the past decade the incidence of tuberculosis has increased nationwide and more than doubled in New York City, where there have been recent nosocomial outbreaks of multidrug-resistant tuberculosis. METHODS: We collected information on every patient in New York City with a positive culture for Mycobacterium tuberculosis during April 1991. Drug-susceptibility testing was performed at the Centers for Disease Control and Prevention. RESULTS: Of the 518 patients with positive cultures, 466 (90 percent) had isolates available for testing. Overall, 33 percent of these patients had isolates resistant to one or more antituberculosis drugs, 26 percent had isolates resistant to at least isoniazid, and 19 percent had isolates resistant to both isoniazid and rifampin. Of the 239 patients who had received antituberculosis therapy, 44 percent had isolates resistant to one or more drugs and 30 percent had isolates resistant to both isoniazid and rifampin. Among the patients who had never been treated, the proportion with resistance to one or more drugs increased from 10 percent in 1982 through 1984 to 23 percent in 1991 (P = 0.003). Patients who had never been treated and who were infected with the human immunodeficiency virus (HIV) or reported injection-drug use were more likely to have resistant isolates. Among patients with the acquired immunodeficiency syndrome, those with resistant isolates were more likely to die during follow-up through January 1992 (80 percent vs. 47 percent, P = 0.02). A history of antituberculosis therapy was the strongest predictor of the presence of resistant organisms (odds ratio, 2.7; P < 0.001). CONCLUSIONS: There has been a marked increase in drug-resistant tuberculosis in New York City. Previously treated patients, those infected with HIV, and injection-drug users are at increased risk for drug resistance. Measures to control and prevent drug-resistant tuberculosis are urgently needed.

Hospital outbreak of multidrug-resistant Mycobacterium tuberculosis infections. Factors in transmission to staff and HIV-infected patients.

OBJECTIVE: To describe transmission of multidrug-resistant (MDR) Mycobacterium tuberculosis infection among patients and health care workers (HCWs) in a ward and clinic for human immunodeficiency virus (HIV)-infected patients in a hospital, four studies were conducted. METHODS: Case patients and control patients were persons who had been treated in the HIV ward or clinic, whose clinical course was consistent with tuberculosis and who had at least one positive culture for M tuberculosis between January 1, 1988, and January 31, 1990, resistant to at least isoniazid and rifampin (case patients), or whose isolates were susceptible to all drugs tested (control patients). In the first study, case patients and control patients were compared to identify risk factors for MDR tuberculosis. In the second study, inpatient and outpatient days of MDR tuberculosis case patients were compared to determine whether acid-fast bacillus (AFB) smear-positivity or aerosolized pentamidine use was associated with higher numbers of subsequent MDR tuberculosis cases among exposed patients. In the third study, restriction fragment length polymorphism analysis was performed on available MDR and sensitive M tuberculosis isolates. In the fourth study, skin test conversion rates among HCWs in the HIV ward and clinic were compared with those of HCWs in another ward, and the strength of the associations between skin test conversions among HCWs on the HIV ward and the number of person-days that AFB smear-positive case patients and control patients were on this ward was estimated. RESULTS: Case patients were more likely than control patients to have been exposed on the HIV ward or clinic to an AFB smear-positive case patient (P less than .001). Inpatient and outpatient days of MDR tuberculosis case patients were associated with more subsequent cases of MDR tuberculosis if exposing case patients were smear-positive or if they received aerosolized pentamidine (P less than or equal to .01). Of 13 MDR isolates, all had one of two restriction fragment length polymorphism patterns; 10 sensitive isolates had restriction fragment length polymorphism patterns that were different from each other. The HCW skin test conversion rate was higher on the HIV ward and clinic than on the comparison ward (P less than .01). The risk of occupational acquisition of infection increased in direct proportion to the number of person-days that AFB smear-positive case patients were on the HIV ward (r = .75; P = .005), but did not increase in proportion to the number of person-days that AFB smear-positive control patients were there (r = -.36; P = NS). After isolation measures for AFB smear-positive tuberculosis patients were improved, MDR tuberculosis cases decreased to seven of 214 tuberculosis patients. CONCLUSIONS: Nosocomial transmission of MDR M tuberculosis infection to patients and HCWs occurred on the HIV ward and clinic. Infectiousness of MDR tuberculosis case patients was associated with AFB sputum-smear positivity. Case patients with MDR tuberculosis created a greater risk of skin test conversion for HCWs on the HIV ward than drug-susceptible control patients.

Nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis. A risk to patients and health care workers.

OBJECTIVE: To determine the factors associated with the development of multidrug-resistant tuberculosis among patients at a New York City Hospital and to investigate possible nosocomial transmission. DESIGN: A retrospective case-control study and tuberculin skin test survey. PATIENTS: Twenty-three patients with tuberculosis whose isolates were resistant to at least isoniazid and rifampin (case patients) were compared with patients with tuberculosis whose isolates were susceptible to all agents tested (controls). Tuberculin skin test conversion rates were compared among health care workers assigned to wards where patients with tuberculosis were frequently or rarely admitted. SETTING: A large, teaching hospital in New York City. MEASUREMENTS: Mycobacterium tuberculosis isolates from case patients and controls were typed by restriction fragment length polymorphism analysis. RESULTS: Case patients were younger (median age, 34 compared with 42 years; P = 0.006), more likely to be seropositive for HIV (21 of 23 compared with 11 of 23 patients; odds ratio, 11.5; 95% CI, 1.9 to 117), and more likely to have had a previous hospital admission within 7 months before the onset of tuberculosis (19 of 23 compared with 5 of 23 patients; odds ratio, 17.1; CI, 3.3 to 97), particularly on one ward (12 of 23 compared with 0 of 23 patients; odds ratio, undefined; P = 0.002). Health care workers assigned to wards housing case patients were more likely to have tuberculin skin test conversions than were health care workers assigned to other wards (11 of 32 compared with 1 of 47 health care workers; P less than 0.001). Few (6 of 23) case patients were placed in acid-fast bacilli isolation, and no rooms tested had negative pressure. Of 16 available multidrug-resistant isolates obtained from case patients, 14 had identical banding patterns by restriction fragment length polymorphism analysis. In contrast, M. tuberculosis isolates from controls with drug-susceptible tuberculosis had patterns distinct from each other and from those of case patients. CONCLUSIONS: These data suggest nosocomial transmission of multidrug-resistant tuberculosis occurred from patient to patient and from patient to health care worker and underscore the need for effective acid-fast bacilli isolation facilities and adherence to published infection control guidelines in health care institutions.

An outbreak of multidrug-resistant tuberculosis among hospitalized patients with the acquired immunodeficiency syndrome.

BACKGROUND: Since 1990 several clusters of multidrug-resistant tuberculosis have been identified among hospitalized patients with the acquired immunodeficiency syndrome (AIDS). We investigated one such cluster in a voluntary hospital in New York. METHODS: We compared exposures among 18 patients with AIDS in whom tuberculosis resistant to isoniazid and streptomycin was diagnosed from January 1989 through April 1990 (the case patients) with exposures among 30 control patients who had AIDS and tuberculosis susceptible to isoniazid, streptomycin, or both. We also compared exposures among the 14 case patients hospitalized during the six months before the diagnosis of tuberculosis (the exposure period) with those among 44 control patients with AIDS matched for duration of hospitalization. Mycobacterium tuberculosis isolates were typed with analysis of restriction-fragment-length polymorphism (RFLP). RESULTS: Case patients with drug-resistant tuberculosis were significantly more likely than controls with drug-susceptible tuberculosis to have been hospitalized during their exposure periods (14 of 18 vs. 10 of 30) (odds ratio, 7.0; 95 percent confidence interval, 1.6 to 36; P = 0.006). Case patients hospitalized during their exposure periods were significantly more likely to have been hospitalized on the same ward as a patient with infectious drug-resistant tuberculosis than were either controls with drug-susceptible tuberculosis hospitalized during their exposure periods or controls matched for duration of hospitalization (13 of 14 vs. 2 of 10 and 23 of 44) (odds ratio, 52; 95 percent confidence interval, 3.1 to 2474; P less than 0.001; and odds ratio, infinity; 95 percent confidence interval, 2.4 to infinity; P = 0.005, respectively). Among those hospitalized on the same ward, the rooms of case patients were closer to that of the nearest patient with infectious tuberculosis than were the rooms of controls matched for duration of hospitalization. M. tuberculosis isolates from 15 of 16 case patients had identical patterns on RFLP analysis. Of 16 patients' rooms tested with air-flow studies, only 1 had the recommended negative-pressure ventilation. CONCLUSIONS: Multidrug-resistant tuberculosis is readily transmitted among hospitalized patients with AIDS. Physicians must be alert to this danger and must enforce adherence to the measures recommended to prevent nosocomial transmission of tuberculosis.

Nosocomial transmission of tuberculosis in a hospital unit for HIV-infected patients.

OBJECTIVE: To assess nosocomial transmission of tuberculosis (TB). DESIGN: A historical cohort study of hospitalized patients with the human immunodeficiency virus (HIV) and a purified protein derivative (PPD) tuberculin skin test survey of health care workers (HCWs). SETTING: A large public teaching hospital in San Juan, Puerto Rico. PATIENTS: For the cohort study, a case patient was defined as any patient in the HIV unit at the hospital who developed culture-positive TB from 31 days or more after admission through December 31, 1989. For the PPD survey, of 1420 HCWs from the hospital, 908 agreed to participate and had sufficient data for analysis. MAIN OUTCOME MEASURES: For the cohort study, to compare the risk of developing active TB among patients who were exposed to hospital roommates with infectious TB and the risk among nonexposed patients. For the HCW PPD survey, to determine the prevalence of and risk factors for tuberculous infection. RESULTS: Eight of 48 (9.7/10,000 person-days) exposed case patients vs four of 192 (0.8/10,000 person-days) nonexposed case patients developed active TB (relative risk [RR] = 11; 95% confidence interval [CI], 2.3, 50.3). Positive PPDs (greater than or equal to 10 mm of induration) in HCWs were associated with older age (P = .0001) and with history of community TB exposure (P = .0002). In a multivariable logistic model that adjusted for these variables, HIV unit nurses (nine of 19) and nurses in the internal medicine ward (45 of 90) had a higher proportion of positive PPDs than the reference group (clerical personnel on other floors: 35 of 188, P = .0005). CONCLUSIONS: These data suggest that patient-to-patient transmission of TB in HIV units can occur and that HCWs are at risk of acquiring TB infection.

Tuberculosis morbidity in the United States: final data, 1990.

The number of tuberculosis cases reported to CDC has been increasing since 1988, after a long historic decline. In 1990, 25,701 cases were reported, an increase of 9.4% over the 1989 figure and the largest annual increase since 1953. From 1985 to 1990, reported cases increased by 15.8%. Disproportionately greater increases in reported cases occurred among Hispanics, non-Hispanic blacks, and Asians/Pacific Islanders. In contrast, decreases were observed among non-Hispanic whites and American Indians/Alaskan Natives. By age, the largest increase in reported cases occurred in the 25- to 44-year age group; this increase may be largely attributable to rising numbers of tuberculosis cases among persons with human immunodeficiency virus infection or acquired immunodeficiency syndrome. Notable increases also occurred among children. The proportion of cases among foreign-born persons has risen steadily, from 21.6% in 1986 to 24.4% in 1990.