1/17. Tuberculosis on the flight deck.Tuberculosis in commercial aircraft has been a concern since a 1995 incident of possible transmission from an active case of tuberculosis to passengers in the cabin of a 747. Subsequently, commercial air carriers have been vigilant in cooperating with public health authorities in tracking all known exposures to tuberculosis. In 1998, a pilot of a commercial airliner was diagnosed with active tuberculosis. Company records demonstrated that in the previous 6 mo, the pilot had flown with 48 other pilots. Every exposed pilot was contacted and evaluated by skin testing (IPPD) or chest x-ray if previously positive. There were no skin test conversions and no changes on x-rays. This study demonstrates that transmission of tuberculosis in the aircraft cabin environment, even under close and continuous exposure to an active case, is a rare event.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
2/17. Transmission of mycobacterium tuberculosis from medical waste.CONTEXT: washington State has a relatively low incidence rate of tuberculosis (TB) infection. However, from May to September 1997, 3 cases of pulmonary TB were reported among medical waste treatment workers at 1 facility in washington. There is no previous documentation of mycobacterium tuberculosis transmission as a result of processing medical waste. OBJECTIVE: To identify the source(s) of these 3 TB infections. DESIGN, SETTING, AND PARTICIPANTS: Interviews of the 3 infected patient-workers and their contacts, review of patient-worker medical records and the state TB registry, and collection of all multidrug-resistant TB (MDR-TB) isolates identified after January 1, 1995, from the facility's catchment area; dna fingerprinting of all isolates; polymerase chain reaction and automated DNA sequencing to determine genetic mutations associated with drug resistance; and occupational safety and environmental evaluations of the facility. MAIN OUTCOME MEASURES: Previous exposures of patient-workers to TB; verification of patient-worker tuberculin skin test histories; identification of other cases of TB in the community and at the facility; drug susceptibility of patient-worker isolates; and potential for worker exposure to live M tuberculosis cultures. RESULTS: All 3 patient-workers were younger than 55 years, were born in the united states, and reported no known exposures to TB. We did not identify other TB cases. The 3 patient-workers' isolates had different DNA fingerprints. One of 10 MDR-TB catchment-area isolates matched an MDR-TB patient-worker isolate by DNA fingerprint pattern. DNA sequencing demonstrated the same rare mutation in these isolates. There was no evidence of personal contact between these 2 individuals. The laboratory that initially processed the matching isolate sent contaminated waste to the treatment facility. The facility accepted contaminated medical waste where it was shredded, blown, compacted, and finally deactivated. Equipment failures, insufficient employee training, and respiratory protective equipment inadequacies were identified at the facility. CONCLUSION: Processing contaminated medical waste resulted in transmission of M tuberculosis to at least 1 medical waste treatment facility worker. JAMA. 2000;284:1683-1688.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
3/17. Uncommon presentations of tuberculosis: the potential value of a novel diagnostic assay based on the mycobacterium tuberculosis-specific antigens ESAT-6 and CFP-10.SETTING: Leiden University Medical Center, Leiden, the netherlands. OBJECTIVE: To illustrate the potential value of a recently developed diagnostic assay for detection of tuberculosis (TB), based on T cell responses to the early secreted antigenic target 6 kDa protein (ESAT-6) and culture filtrate protein 10 (CFP-10). These antigens are mycobacterium tuberculosis specific because they are expressed by M. tuberculosis but absent from M. bovis bacille Calmette-Guerin (BCG) and most environmental mycobacteria. In recent studies, the assay had a high sensitivity and specificity for detection of active TB. DESIGN: We describe five patients with uncommon presentations of tuberculosis, in whom the diagnosis was delayed by negative or conflicting results of diagnostic procedures aimed at detection of M. tuberculosis and an uninformative tuberculin skin test. IFN-gamma production in response to ESAT-6 and CFP-10 by peripheral blood mononuclear cells from these patients was evaluated before and during anti-tuberculosis treatment. RESULTS: In all five patients, IFN-gamma responses to ESAT-6 and/or CFP-10 were above the cut-off level defined in a previous study. During treatment, IFN-gamma responses generally increased. CONCLUSION: These results indicate that T cell responses to M. tuberculosis-specific antigens have potential diagnostic value when TB is suspected and the results of other diagnostic tests are inconclusive, especially in BCG-vaccinated individuals.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
4/17. Epidemiological and economical impact of tuberculosis in an adolescent girl in Lausanne (switzerland).patients with pulmonary tuberculosis (TB) can infect people in their environment but children and adolescents are rarely contagious. A recent case of an adolescent girl in Lausanne, however, proved to be infectious and required extensive contact tracing. SUBJECTS AND METHODOLOGY: The source case was a 15-years-old adolescent girl of African origin. Upon her arrival in switzerland in 1994 the tuberculin skin test was 14 mm. The patient did not receive preventive treatment. She developed smear-positive pulmonary tuberculosis in May 1999. contact tracing identified contacts in the surrounding population. The contact persons were divided into 3 groups according to their proximity. The first group consisted of close family and friends, the second of classmates and teachers and the third of more distant contacts. Costs were also evaluated. RESULTS: Of the 53 people examined, 24 (45%) were infected and required treatment. Eight out of 9 cases (88%) were infected in the first group (including another case of culture-positive pulmonary tuberculosis). Fourteen out of 33 cases (42%) in the second group and 2 of 11 (18%) to the third group. Passing from one proximity group to the next decreased the relative risk of infection 4 fold. The costs of contact tracing and treatment are estimated at over CHF 24,000. CONCLUSIONS: (1) Pulmonary TB can be contagious even in adolescents. (2) Subdividing contacts into proximity groups allows for better targeting of the people to be screened. (3) contact tracing and the high costs involved could have been avoided if the patient had received preventive chemotherapy upon her arrival in switzerland.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
5/17. mycobacterium tuberculosis transmission among high school students in greece.BACKGROUND: The aim of this study was to investigate the requirements and practical steps for screening of mycobacterium tuberculosis (MTB) transmission among high school student populations in two regional high schools of central greece. Case-matched control populations from other regional schools were included. methods: Case study of two indexed cases, 61 close contacts, 212 casual contacts and 369 controls were investigated. Detailed questionnaires, tuberculin-skin test (PPD test), chest radiography, medical evaluation and dna fingerprinting of sputum isolates were used. RESULTS: In case A, three (1.97%) of 152 close and casual contacts developed tuberculosis, and a further 25 (16.4%) were classified as infected. In contrast, none of the 121 close or casual contacts investigated for Case B developed tuberculosis or were classified as infected. None of the control populations contained infected individuals. Contacts of case A had a much higher risk (3.08 < RR = 22.29 < 161.69, P < 0.001) of being infected than contacts of case B. Two different strains of MTB were found responsible for these outbreaks. CONCLUSION: There was a considerable difference in the infectivity of the two cases presumably due to environmental and clinical factors, although two different MTB strains were responsible. It is proposed that the extent of case investigation should be individualized with particular emphasis placed among close contacts.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
6/17. The use of environmental factors as adjuncts to traditional tuberculosis contact investigation.SETTING: A 25-year-old university student was diagnosed with cavitary pulmonary and laryngeal tuberculosis following symptoms of underlying cough of 6 months' duration. OBJECTIVES: To estimate the hourly risk of infection (HRI) and examine the role of environmental factors, including room size and ventilation, in modulating this risk. methods: Contact investigation. RESULTS: Of 1100 contacts identified, 78.3% (n = 896) received a tuberculin skin test (TST), of whom 27.5% had a positive result. Among 634 Canadian-born contacts tested, 22.7% had a positive TST. The independent risk factors for a positive TST among Canadian-born university students were: > 35 h spent with the index case (adjusted OR 6.6, 95% CI 1.0-44.9) and smaller classroom size (aOR 5.0, 95% CI 1.4-10.0). In the first school term, the HRI among Canadian-born student contacts was 0.9%; in the second term, it was 1.6%. CONCLUSION: There are inherent limitations in generalising findings from an outbreak investigation, due to the considerable variation in the infectiousness of cases. Nevertheless, in situations where the index case has a high degree of infectiousness, and there are numerous contacts with low expected prevalence of infection, the HRI can, together with ventilation measurements, be useful in guiding the extent of contact investigation needed.- - - - - - - - - - ranking = 5keywords = environment (Clic here for more details about this article) |
7/17. High incidence of pulmonary tuberculosis in pathologists at Tokai University Hospital: an epidemiological study.Between 1935 and 1950 tuberculosis was the most common cause of death in japan. Subsequently, the mortality rate, incidence, and prevalence of tuberculosis have decreased remarkably due to socioeconomic improvements and development of specific chemotherapy. It has been suspected that the incidence and prevalence of pulmonary tuberculosis in hospital workers, particularly those employed in pathology divisions, may be higher than those for other health care workers. However, there have been no reports on this subject. We conducted a questionnaire survey to assess and compare the incidence of pulmonary tuberculosis in pathologists at Tokai University Hospital with that in other employees of the University. Data on history of treatment for tuberculosis were obtained. The incidence of pulmonary tuberculosis in pathologists was significantly higher than that in other university employees, including clinical doctors who see patients with tuberculosis. These findings suggest that specific environmental conditions in the pathology Division represent an occupational hazard although the infection might be contracted from other hospital staff.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
8/17. Pulmonary sporotrichosis: review of treatment and outcome.Four culture-documented cases of pulmonary sporotrichosis, three primary infections and one with multisystem involvement, are presented. Two of these patients are the first reported cases of primary lung disease treated with ketoconazole. This antifungal agent appears to be ineffective in eradicating this infection. The four cases, as well as a review of the literature, illustrate several important aspects of this rare disease. Pulmonary sporotrichosis is most commonly found in males with a history of alcohol abuse who are between the ages of 30 and 60. The infection is usually confined to the parenchyma of the lung but can involve hilar and mediastinal lymph nodes, pleura, skin, subcutaneous tissue, and joints. All but two cases have been reported in the united states, and the majority reside within states bordering the missouri or mississippi rivers. Direct occupational or environmental exposure appears to be an important predisposing risk factor. The onset of the disease is insidious, presenting in a manner similar to many other granulomatous or neoplastic diseases. Tuberculosis is the most common suspected diagnosis before confirmation of sporotrichosis. The chest radiograph most commonly demonstrates upperlobe cavitary disease with surrounding parenchymal infiltrates. The diagnosis can be suspected with high serologic titers or skin-test positivity, but needs to be confirmed by culture. The organism can usually be grown from sputum, as well as routine bronchoscopic procedures, open-lung biopsy specimens or pleural fluid. Histologic examination shows granulomas of both the caseating and noncaseating varieties. Frequently, organisms can be seen in necrotic areas of the lung tissue by diastase-modified GMS or PAS staining. Staining by direct fluorescent antibody technique can also be done and appears to be highly specific. Treatment is controversial, but total surgical resection of diseased lung as well as a perioperative regimen of SSKI or amphotericin b appears to be the most efficacious therapy. Medical therapy alone with SSKI or amphotericin b may be useful in selected cases but has been disappointing in the majority of reports. The imidazoles are usually ineffective, and the search for more effective medical therapy continues.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
9/17. Neonatal tuberculosis.Tuberculosis rarely presents in the neonatal period. Though treatable, it may be fatal despite modern treatment. The diagnosis of congenital tuberculosis should be considered in any neonate with pneumonia that fails to respond to conventional treatment, particularly in a child from an ethnic or socioeconomic environment where tuberculosis is prevalent.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
10/17. Indoor infection in a modern building.Outbreaks of tuberculosis (TB), which are of a type rarely experienced in the past, have recently increased in japan. An example of such an outbreak, which occurred in a modern building with fixed sash windows, will be described. The occurrence of four TB cases, which had been found during the period between May 1979 and June 1980 among company employees working in the same building in downtown tokyo, motivated the conduct of epidemiological and environmental surveys on this episode. The first case, a 36-year-old male with a positive smear and cavities in both lungs, was considered to have been in an infectious state for about one year before his admission to a TB hospital in June 1979. Follow-up investigation of 99 contacts until March 1982 revealed the occurrence of 16 secondary cases. The secondary attack rate was highest among those working on the same floor of the building as this first case, but no case was found among employees of another company that occupied this building. The desks of secondary cases were aggregated near and around that of the first case. Although this building had central air-conditioning, ventilation was often closed for energy conservation purposes. This resulted in the increase of carbon dioxide concentration in the air up to a level of more than 1,000 ppm during working hours and to as high as 2,000 ppm when the ventilation was closed. It was thus concluded that the indoor infection of TB in this episode was attributable to the insufficient ventilation in the building.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
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