Incremental yield of bronchial washing for diagnosing smear-negative pulmonary tuberculosis

Abstract

OBJECTIVE:To assess the increased diagnostic yield for pulmonary tuberculosis using bronchial washing cultures compared with sputum cultures. METHODS:Study conducted with 61 adults in Lima, Peru, from January 2006 to December 2007. The yield of sputum cultures was compared with the yield of acid-fast bacilli smears and cultures of bronchial washing for diagnosing pulmonary tuberculosis in suspected cases of clinical tuberculosis with negative acid fast bacilli sputum smears. RESULTS:Twenty seven (95%CI 32;58) of the cases were eventually diagnosed with smear-negative pulmonary tuberculosis. Bronchial washing samples detected 23 (95%CI 72;99) of the smear-negative pulmonary tuberculosis cases compared with 15 (95%CI 37;74) for sputum cultures (p = 0.02). The incremental diagnostic yield of acid fast bacilli smear and culture of bronchial washing specimens over sputum culture was 44% (95%CI 25;65). CONCLUSIONS:In function of the epidemiological context and the resources available, bronchoscopy should be deployed as part of a comprehensive work up that optimizes smear-negative pulmonary tuberculosis diagnosis and minimizes risk and costs. 814Incremental yield of bronchial washing for TB Soto A et al According to World Health Organization (WHO), smear negative pulmonary tuberculosis (SNPT) is defi ned as a case with at least two negative sputum acid fast bacilli (AFB) smears and either a positive culture or radiographic abnormalities consistent with tuberculosis and failure to respond to an antibiotic trial. 5Microbiological tests on fl exible bronchoscopy samples are considered useful for the diagnosis of SNPT, but their indication is not standardized. The procedure is performed on the premise that the bacillary load is higher in samples from bronchial secretions than in sputum. However, bronchoscopy is not without risk for patients and may be associated with nosocomial transmission of tuberculosis.The reported sensitivity in patients with clinical suspicion of tuberculosis varies from as low as 6.5% to up to 77%. 2 However, evaluations of bronchoscopy are scarce, specifi cally for the detection of SNPT in prospective studies. Additionally, culture in liquid media is seldom performed. It is more sensitive than culture in conventional solid media of sputum and recommended by the WHO, 4 but whether this is also the case for bronchoscopy samples is less clear. RESUMO OBJETIVO:Avaliar o aumento do rendimento do diagnóstico de tuberculose pulmonar mediante cultura de lavado brônquico em comparação ao rendimento da cultura de escarro. MÉTODOS:Estudo realizado com 61 adultos da cidade de Lima, Peru, a partir de janeiro de 2006 a dezembro de 2007. Foi comparado o rendimento de culturas de escarro com o de esfregaço de bacilos ácido-resistentes e cultura de amostras de lavado brônquico para diagnóstico de tuberculose pulmonar, em casos suspeitos de tuberculose clínica, com esfregaço de escarro de bacilos ácido-resistentes negativo. RESULTADOS:Vinte e sete (IC95% 32;58) dos casos foram diagnosticados com tuberculos...

Evaluación en condiciones de campo de una prueba serológica rápida para detección de anticuerpos IgM e IgG contra SARS-CoV-2

“…Se obtuvo el porcentaje de pruebas positivas por cada uno de los métodos. El rendimiento diagnóstico adicional se calculó dividiendo el número de casos adicionales diagnosticados por las pruebas rápidas sobre el número total de casos detectados por ambos métodos, expresado en porcentaje (9) . Además, se realizó la estimación de la sensibilidad de la prueba serológica rápida usando el RT-PCR como estándar de referencia.…”

Indicators for prediction of Mycobacterium tuberculosis positivity detected with bronchoalveolar lavage fluid

“…In order to maximize the benefit of bronchoscopy while minimizing the cost to TB control programs, it is important to identify parameters to predict the yield of BALF for diagnosis of sputum- negative pulmonary TB [9]. In the present study, we compared the sensitivity and specificity of Mtb tests between sputum and BALF for diagnosis of pulmonary TB among 1539 sputum-smear-negative cases, and identified clinical parameters which are associated with the benefit of bronchoscopy in sputum-negative and non-sputum-producing pulmonary TB suspects.…”

Diagnostic Yield of Fiberoptic Bronchoscopy Washings among Patients of Sputum Smear Negative Pulmonary Tuberculosis

“…8 One study estimated that FOB samples has diagnostic yield of 85%. 9 Another study showed the overall diagnostic yield of FOB was 55% for diagnosis of disease in smear negative PTB cases. 10 Similarly, our results showed high diagnostic value of FOB thus in line with above mentioned studies.…”

“…8 One study estimated that FOB samples has diagnostic yield of 85%. 9 Another study showed the overall diagnostic yield of FOB was 55% for diagnosis of disease in smear negative PTB cases. 10 Our results helped us in making definitive diagnosis of PTB and to avoid injudicious administration of anti-tuberculosis treatment to patients.…”