Sputum microscopy for the diagnosis of HIV-associated pulmonary tuberculosis in Tanzania.
BMC Public Health
; 8: 68, 2008 Feb 21.
Article
em En
| MEDLINE
| ID: mdl-18289392
ABSTRACT
BACKGROUND:
In many resource poor settings only sputum microscopy is employed for the diagnosis of HIV-associated pulmonary tuberculosis; sputum culture may not be available.METHODS:
We determined the diagnostic accuracy of sputum microscopy for active case finding of HIV-associated pulmonary tuberculosis using TB culture as the reference standard.RESULTS:
2216 potential subjects screened for a TB vaccine trial submitted 9454 expectorated sputum specimens 212 (2.2%) were sputum culture positive for Mycobacterium tuberculosis (MTB), 31 (0.3%) for non-tuberculous mycobacteria, and 79 (0.8%) were contaminated. The overall sensitivity of sputum microscopy was 61.8% (131/212) and specificity 99.7% (9108/9132). Sputum microscopy sensitivity varied from 22.6% in specimens with < 20 colony forming units (CFU)/specimen to 94.2% in patients with > 100 CFU/specimen plus confluent growth. The incremental diagnostic value for sputum microscopy was 92.1%, 1.8% and 7.1% for the first, second and third specimens, respectively. The positive predictive value and negative predictive values for sputum microscopy were 84.5% and 99.1%, respectively. The likelihood ratio (LR) of a positive sputum microscopy was 235.1 (95% CI 155.8 - 354.8), while the LR of a negative test was 0.38 (95CI 0.32 - 0.45). The 212 positive sputum cultures for MTB represented 103 patients; sputum microscopy was positive for 57 (55.3%) of 103 patients.CONCLUSION:
Sputum microscopy on 3 expectorated sputum specimens will only detect 55% of culture positive HIV-infected patients in active screening for pulmonary tuberculosis. Sensitivity is higher in patients with greater numbers of CFUs in the sputum. Culture is required for active case finding of HIV- associated pulmonary tuberculosis.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Escarro
/
Tuberculose Pulmonar
/
Infecções por HIV
/
Infecções Oportunistas Relacionadas com a AIDS
/
Mycobacterium tuberculosis
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Female
/
Humans
/
Male
País como assunto:
Africa
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article