Transmission of Mycobacterium tuberculosis from patients smear-negative for acid-fast bacilli.
Background The microscopic examination of sputum for acid-fast bacilli, is a simple and rapid test that is used to provide a presumptive diagnosis of infectious tuberculosis.
While patients with tuberculosis with sputum smears negative for acid-fast bacilli are less infectious than those with positive smears, both theoretical and empirical evidence suggest that they can still transmit Mycobacterium tuberculosis.
We aimed to estimate the risk of transmission from smear-negative individuals.
Methods As part of an ongoing study of the molecular epidemiology of tuberculosis in San Francisco, patients with tuberculosis with mycobacterial isolates with the same DNA fingerprint were assigned to clusters that were assumed to have involved recent transmission.
Secondary cases with tuberculosis, whose mycobacterial isolates had the same DNA, were linked to their presumed source case to estimate transmission from smear-negative patients.
Sensitivity analyses were done to assess potential bias due to misclassification of source cases, unidentified source cases, and HIV-1 co-infection.
Findings 1574 patients with culture-positive tuberculosis were reported and DNA fingerprints were available for 1359 (86%) of these patients.
Of the 71 clusters of patients infected with strains that had matching fingerprints, 28 (39% [95% Cl 28-52]) had a smear-negative putative source. (...)
Mots-clés Pascal : Tuberculose, Mycobactériose, Bactériose, Infection, Frottis, Expectoration, Mycobacterium tuberculosis, Mycobacteriaceae, Mycobacteriales, Actinomycetes, Bactérie, Transmission, Epidémiologie, Evaluation, Risque, Homme
Mots-clés Pascal anglais : Tuberculosis, Mycobacterial infection, Bacteriosis, Infection, Smear, Sputum, Mycobacterium tuberculosis, Mycobacteriaceae, Mycobacteriales, Actinomycetes, Bacteria, Transmission, Epidemiology, Evaluation, Risk, Human
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0136334
Code Inist : 002B05B02O. Création : 16/11/1999.