RESUMO
BACKGROUND: Clinical data with use of serial interferon-γ release assay (IGRA) testing in US health-care workers (HCWs) are limited. METHODS: A single-center, retrospective chart review was done from 2007 to 2010 of HCWs who underwent preemployment QuantiFERON-TB Gold In-Tube testing. Demographic data, bacille Calmette-Guérin history, prior tuberculin skin test result if done, and baseline and serial IGRA values were obtained. The number of IGRA converters and reverters and their subsequent management by infectious disease physicians were reviewed. Quantitative IGRA-negative values were not available. RESULTS: A total of 7,374 IGRAs were performed on newly hired HCWs. Of these tests, 486 (6.6%) were positive at baseline, 305 (4.1%) were indeterminate, and 6,583 (89.3%) were negative. From 2007 to 2010, 52 of 1,857 HCWs (2.8%) with serial IGRA tests were identified as converters, with a serial IGRA median value of 0.63 IU/mL. Seventy-one percent of HCWs with IGRA conversion had values ≤ 1 IU/mL. None of the converters had active TB or were part of an outbreak investigation. CONCLUSIONS: Clinical significance of most QuantiFERON-TB Gold In-Tube conversions in serial testing remains a challenging task for clinicians. The use of a single cutoff point criterion for IGRA may lead to overdiagnosis of new TB infections. Clinical assessment and evaluation may help to prevent unnecessary therapy in these cases. The criteria for defining conversions and reversions by establishing new cutoffs needs to be evaluated further, especially in HCWs.
Assuntos
Pessoal de Saúde , Testes de Liberação de Interferon-gama/normas , Programas de Rastreamento/métodos , Tuberculose/diagnóstico , Adolescente , Adulto , Feminino , Humanos , Transmissão de Doença Infecciosa do Profissional para o Paciente/prevenção & controle , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Teste Tuberculínico , Tuberculose/epidemiologia , Adulto JovemRESUMO
A real-time PCR assay for the mip gene of Legionella pneumophila was tested with 27 isolates of L. pneumophila, 20 isolates of 14 other Legionella species, and 103 non-Legionella bacteria. Eight culture-positive and 40 culture-negative clinical specimens were tested. This assay was 100% sensitive and 100% specific for L. pneumophila.