Nosocomial Transmission Of Multidrug-resistant Tuberculosis Research Articles

Nosocomial transmission of multidrug-resistant tuberculosis.

Nosocomial transmission of multidrug-resistant tuberculosis (MDR-TB) was ascertained by 24-locus mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) and spoligotyping at four hospitals in the Republic of Moldova, a high MDR-TB burden country. Overall, 5.1% of patients with pan-susceptible TB at baseline were identified with MDR-TB during in-patient treatment. In 75% of cases, the MDR-TB strain was genetically distinct from the non-MDR-TB strain at baseline, suggesting a high rate of nosocomial transmission of MDR-TB. The highest proportion (40.3%) of follow-up MDR-TB isolates was associated with the M. tuberculosis URAL 163-15 strain.

Tuberculosis Control Is a Team Sport

An especially disturbing characteristic of the recent tuberculosis (TB) epidemic was the transmission of TB in hospitals and other institutional settings. 1 Davis YM McCray E Simone PM Hospital infection control practices for tuberculosis.. Clin Chest Med. 1997; 18: 19-33 Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar Although multiple factors contributed to nosocomial TB transmission, a common critical element was the delayed diagnosis of contagious TB cases. In response to this threat to both health-care workers and patients, the Centers for Disease Control and Prevention (CDC) generated new guidelines mandating more rigorous institutional TB control measures. 2 Guidelines for preventing the transmission of Mycobacterium tuberculosis in health-care facilities.. MMWR. 1994; 43 (RR-13): 1-132 Google Scholar Adoption of these measures, as well as the declining incidence of TB in the United States, are associated with decreased nosocomial TB transmission. 3 Maloney SA Pearson ML Gordon MT et al. Efficacy of control measures in preventing nosocomial transmission of multidrug-resistant tuberculosis to patients and health care workers.. Ann Intern Med. 1995; 122: 90-95 Crossref PubMed Scopus (159) Google Scholar , 4 Stroud LA Tokars JI Grieco MH et al. Evaluation of infection control measures in preventing the nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis in a New York City hospital.. Infect Control Hosp Epidemiol. 1995; 16: 141-147 Crossref PubMed Scopus (63) Google Scholar , 5 Centers for Disease ControlTuberculosis morbidity – US 1996.. MMWR. 1997; 46: 695-699 PubMed Google Scholar I believe, however, that the decreased risk to health-care workers is at least equally the result of a massive TB education effort targeting health-care workers. Without the increased TB awareness that results in the rapid identification of contagious TB cases, no institutional control measures would be successful. In this issue of CHEST (see page 681), Divinagracia and colleagues describe an unintended but perhaps predictable financial liability that arose in concert with the success of the education effort. Overly aggressive TB diagnostic efforts can be viewed, in fact, as a hard won victory over the previous lack of TB awareness. If there were no excessive costs associated with the aggressive evaluation of all conceivable TB suspects, then there would be no problem. There is a problem, of course, because aggressive evaluation of TB is expensive, but the results of this study also demonstrate how cooperation between primary care providers and TB specialists can reduce unnecessary expenditure of medical resources without compromising patient care.

Transmission of a Highly Drug-Resistant Strain (Strain W1) of Mycobacterium tuberculosis

Nosocomial transmission of multidrug-resistant tuberculosis (MDR TB) has been reported primarily in New York State and has generally been presumed to occur via respiratory aerosols. To assess nosocomial transmission of MDR TB. In 1995, 8 patients with MDR TB were identified in South Carolina; all were resistant to 7 drugs and had matching DNA fingerprints (strain W1). Community linkswere identified for 5 patients (Patients 1-5). However, no links were identified forthe other 3 patients (Patients 6-8) except being hospitalized at the same hospital as 1 community patient. Outbreak investigation. Community and hospital. Eight patients whose MDR TB isolates had DNA fingerprint patterns matching strain W1. Clinical characteristics of patients with strain W1 Mycobacterium tuberculosis isolates. Patient 5 (community patient) and Patient 8, diagnosed April 1995 and November 1995, respectively, had clinical courses consistent with MDR TB, with smear-positive and culture-positive specimens and cavitary lesions on chest radiograph; both died of MDR TB less than 1 month after diagnosis. Patients 6 and 7 (diagnosed May 1995) each had 1 positive culture for MDR TB; specimens were collected during bronchoscopy. Patient 6 had a skin test conversion after bronchoscopy. Neither Patient 6 nor Patient 7 had a clinical course consistent with MDR TB, neither was treated for MDR TB, and both are alive and well. No evidence of laboratory contamination of specimens, transmission on inpatient wards, or contact among patients was found. All 4 received bronchoscopies in May 1995; Patients 6, 7, and 8 had bronchoscopies 1, 12, and 17 days, respectively, after Patient 5. Observations revealed that bronchoscope cleaning was inadequate, and the bronchoscope was never immersed in disinfectant. Inadequate cleaning and disinfection of the bronchoscope after the procedure performed on Patient 5 led to subsequent false-positive cultures in Patients 6 and 7 and transmission of infection to Patient 6 and active MDR TB to Patient 8.

A Death Associated With Therapy for Nosocomially Acquired Multidrug-Resistant Tuberculosis

Treatment of multidrug-resistant tuberculosis is difficult and has been associated rarely with severe side effects. We report the nosocomial transmission of multidrug-resistant tuberculosis to a health-care worker who was seronegative for HIV infection. She died because of liver failure associated with treatment for active multidrug-resistant tuberculosis.

Prospective Evaluation of the Utility of Molecular Techniques for Diagnosing Nosocomial Transmission of Multidrug-Resistant Tuberculosis

To compare molecular techniques with conventional diagnostic methods for evaluating nosocomial transmission of multidrug-resistant tuberculosis (MDR-TB). We conducted a 12-week postexposure inception cohort study of health-care personnel who had been exposed to a patient with MDR-TB. In addition to baseline and follow-up tuberculin skin tests and chest roentgenography, weekly pulmonary specimens were evaluated by (1) auramine-rhodamine fluorescent staining, (2) culture for mycobacteria, and (3) polymerase chain reaction (PCR) to amplify IS6110, a nucleic acid insertion sequence unique to the Mycobactrium tuberculosis complex. The index patient's isolate of M. tuberculosis showed a mutation in codon 531 of the RNA polymerase beta subunit (rpoB) gene of M. tuberculosis, which is associated with rifampin resistance and considered a marker for this MDR-TB strain. All pulmonary and gastric specimens from study participants had negative auramine stains and cultures for mycobacteria, One person, however, had separate specimens with repeatedly positive PCR results for IS6110 sequences, but the specimens contained a wild-type M. tuberculosis rpoB codon 531 dissimilar from the index patient's strain. Although both molecular and conventional testing showed that no exposed person was infected with the MDR-TB strain, molecular test results were available sooner and seemed more sensitive for detecting M. tuberculosis in one exposed person, presumably in a preinfection or "colonized" stage. Molecular methods provided information that helped distinguish this person's M. tuberculosis strain from the index patient's MDR-TB strain. Additional prospective studies should assess the value of these molecular techniques in similar clinical settings.

Institutional Control Measures for Tuberculosis in the Era of Multiple Drug Resistance: ACCP/ATS Consensus Conference

Institutional Control Measures for Tuberculosis in the Era of Multiple Drug Resistance: ACCP/ATS Consensus Conference

Multidrug-Resistant Tuberculosis in Patients With AIDS

In a large retrospective study, Weltman and Rose 1 found that the vast majority of multidrug-resistant (MDR) tuberculosis (TB) cases observed at a New York City hospital in the years 1991 and 1992 were diagnosed in patients with acquired immunodeficiency syndrome (AIDS). Prior episodes of nosocomial transmission of MDR TB, in which some of the patients investigated were involved, may well account for the association between AIDS and MDR TB that they described. 2,3 The latter may thus be interpreted as a temporal and spatial clustering of subjects that belong to a group that is at high risk for TB. On the basis of the current literature on MDR TB, however, it seems that the association between MDR strains of Mycobacterium tuberculosis and subjects with human immunodeficiency virus (HIV) infection goes beyond both the recognized vulnerability of these patients to TB and some circumstantial episodes of exposure to such resistant

Efficacy of control measures in preventing nosocomial transmission of multidrug-resistant tuberculosis to patients and health care workers.

To assess the efficacy of control measures in decreasing nosocomial transmission of multidrug-resistant tuberculosis. Retrospective cohort study. A teaching hospital in New York City. 40 patients hospitalized with multidrug-resistant tuberculosis (case-patients) and health care workers receiving tuberculin skin testing. Centers for Disease Control and Prevention (CDC) 1990 guidelines for preventing transmission of tuberculosis, including 1) prompt isolation and treatment of patients with tuberculosis; 2) rapid diagnostic techniques for processing Mycobacterium tuberculosis specimens; 3) negative-pressure isolation rooms; and 4) molded surgical masks for health care workers. Proportion of case-patients with nosocomially acquired tuberculosis and rate of tuberculin skin test conversion among health care workers before and after implementation of control measures. The proportion of patients with multidrug-resistant strains of M. tuberculosis decreased after the interventions (10 of 70 [14%] compared with 30 of 95 [32%] patients before the intervention; relative risk [RR], 0.5; 95% CI, 0.2 to 0.9). Before onset of multidrug-resistant tuberculosis, case-patients in the intervention period were as likely to be hospitalized on high-risk wards containing patients with tuberculosis (4 of 10 compared with 17 of 30 patients; RR, 0.7; P = 0.5) but were less likely to be exposed to another case-patient with tuberculosis (1 of 10 compared with 20 of 30 patients; RR, 0.2; P = 0.003). Tuberculin skin test conversion rates for health care workers assigned to wards housing patients with tuberculosis were lower in the intervention period than in the preintervention period (4 of 78 [5%] compared with 15 of 90 [17%] conversions; P = 0.02), decreasing to levels observed for workers assigned to other wards (4 of 78 [5%] compared with 9 of 228 [4%] conversions; P = 0.7). Implementing control measures reduced nosocomial transmission of multidrug-resistant strains to patients and health care workers.

Transmission of multidrug-resistant Mycobacterium tuberculosis among persons with human immunodeficiency virus infection in an urban hospital: epidemiologic and restriction fragment length polymorphism analysis.

From January 1990 to December 1991, 16 patients with multidrug-resistant tuberculosis (MDR-TB) caused by Mycobacterium tuberculosis resistant to isoniazid, rifampin, and streptomycin were diagnosed at Elmhurst Hospital. Compared with other TB patients, MDR-TB patients were more likely to have human immunodeficiency virus (HIV) infection (14/16 vs. 21/204, P < .001) and a prior admission (10/16 vs. 3/204, P < .001). HIV-infected patients hospitalized for > 10 days within three rooms of an infectious MDR-TB patient had higher risk of acquiring MDR-TB than did HIV-infected patients with shorter hospitalizations or locations further from the MDR-TB patient(s) (6/28 vs. 2/90, P < .001). Isolates of 6 of 8 MDR-TB patients in a chain of transmission were identical by restriction fragment length polymorphism DNA typing. Ambulation on the wards of inadequately masked TB patients and lack of negative pressure in isolation rooms probably facilitated transmission. This report documents nosocomial transmission of MDR-TB and underscores the need for effective isolation practices and facilities in health care institutions.

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

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. A retrospective case-control study and tuberculin skin test survey. 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. A large, teaching hospital in New York City. Mycobacterium tuberculosis isolates from case patients and controls were typed by restriction fragment length polymorphism analysis. 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. 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.