Rifampicin (RMP) resistance was compared with a culture-based
method and rpoB gene sequencing. We also assessed the limit of detection for mutant proportions and time savings in diagnosis.
RESULTS: The Xpert MTB/RIF assay detected M. tuberculosis in 71 (100%) specimens (32 smear-positive, 39 smear-negative). This assay showed 100% (62/62) concordance with drug resistance confirmed by culture and 98.4% (61/62) concordance with sequencing. A specimen containing approximately 50% of mutant p.His526Tyr was falsely interpreted as wild-type bacilli by this assay. The minimal detection ratio was 5:1 of mutant vs. wild-type cells. The median time saved was 18.5 days (range 9-30) for the diagnosis of M. tuberculosis and 81.5 days (65-136) for RMP susceptibility
in smear-negative, culture-positive GSK1210151A patients.
CONCLUSIONS: The Xpert MTB/RIF assay showed high sensitivity in detecting M. tuberculosis with information on RMP resistance, and had a more rapid time to diagnosis compared to conventional tests; however, the location and amount of mutation may affect test sensitivity.”
“SETTING: After the diagnosis of a case of tuberculosis (TB), contact tracing is directed by the risk of transmission, for which sputum acid-fast bacilli (AFB) staining results are highly relevant. Limited data are available on the effect of the degree of acid-fast positivity, of a polymerase chain reaction (PCR) result or of bronchoalveolar lavage (BAL) fluid
results on the risk of transmission.
OBJECTIVES: To investigate factors associated with TB transmission, p38 MAPK cancer focusing on quantitative sputum smear results.
DESIGN: Retrospective study of contact investigations performed over a period of 5 years in a Dutch Municipal Health Service among all index patients with TB, and the tuberculin skin test and chest radiography results in contacts. Three definitions of transmission were contacts.
RESULTS: The highest (+4/+5) sputum AFB grades were associated with the highest relative risk (>= 8) of extensive transmission or active TB among contacts. Novel risk factors observed were employment or school attendance, positive PCR of sputum and positive AFB staining of BAL fluid. Pulmonary symptoms, infiltrate or cavity and positive AFB sputum stain were also associated with transmission, confirming previous learn more studies.
CONCLUSION: The risk factors observed in this study may aid in the extension of contact investigations.”
“SETTING: Health care workers (HCWs) are at increased risk for tuberculosis (TB) infection. In China, surveys examining TB infection among HCWs have not studied general health care facilities, compared tuberculin tests conducted using local protocols against an internationally accepted test or characterised risk factors.
OBJECTIVE: To measure the prevalence of and risk factors for TB infection among HCWs in Inner Mongolia, China.