Abstract
SETTING: Royal Free Hospital, London.
OBJECTIVE: To investigate the relationship between
sputum mycobacterial load, assessed by time to positivity
(TTP) in liquid culture, radiological cavitation and
change in sputum bacterial load in response to antit
uberculosis treatment.
DESIGN: The study was conducted on 95 patients
treated for sputum culture-positive pulmonary tuberculosis
(TB), with pre-treatment TTP and baseline chest
X-ray (CXR). Of these, 31 had chest computed tomography
scans assessed for number and volume of cavities.
The microbiological treatment response was measured
in 56 patients with serial TTP, and related to baseline
radiological cavitation.
RESULTS: Cavitation was present in 48% of patients,
and was associated with a shorter TTP at baseline (P <
0.001). Patients with more cavities and greater total cavitary
volume had a shorter TTP (P < 0.001 for both).
No difference was demonstrated in the rate of change in
TTP on treatment (P = 0.36) between patients with and
without cavities.
CONCLUSION: This study confi rms that cavitation is
associated with higher baseline sputum mycobacterial
load. The rate of decline in bacterial load in response to
treatment is similar in patients with and without radiologically
demonstrable cavities, suggesting that response
to, and hence duration of, effective treatment may be
predicted by the initial number of organisms present in
the sputum.
KEY WORDS: BacT/ALERT® 3D Mycobacteria detection
systems; time to culture positivity; sputum mycobacterial
load; chest X-ray; chest CT
OBJECTIVE: To investigate the relationship between
sputum mycobacterial load, assessed by time to positivity
(TTP) in liquid culture, radiological cavitation and
change in sputum bacterial load in response to antit
uberculosis treatment.
DESIGN: The study was conducted on 95 patients
treated for sputum culture-positive pulmonary tuberculosis
(TB), with pre-treatment TTP and baseline chest
X-ray (CXR). Of these, 31 had chest computed tomography
scans assessed for number and volume of cavities.
The microbiological treatment response was measured
in 56 patients with serial TTP, and related to baseline
radiological cavitation.
RESULTS: Cavitation was present in 48% of patients,
and was associated with a shorter TTP at baseline (P <
0.001). Patients with more cavities and greater total cavitary
volume had a shorter TTP (P < 0.001 for both).
No difference was demonstrated in the rate of change in
TTP on treatment (P = 0.36) between patients with and
without cavities.
CONCLUSION: This study confi rms that cavitation is
associated with higher baseline sputum mycobacterial
load. The rate of decline in bacterial load in response to
treatment is similar in patients with and without radiologically
demonstrable cavities, suggesting that response
to, and hence duration of, effective treatment may be
predicted by the initial number of organisms present in
the sputum.
KEY WORDS: BacT/ALERT® 3D Mycobacteria detection
systems; time to culture positivity; sputum mycobacterial
load; chest X-ray; chest CT
| Original language | English |
|---|---|
| Pages (from-to) | 1596-1602 |
| Number of pages | 7 |
| Journal | International Journal of Tuberculosis and Lung Disease |
| Volume | 14 |
| Issue number | 12 |
| Publication status | Published - Dec 2010 |
