|Description||85% of clinical tuberculosis presents as pulmonary tuberculosis. Identification of the presence of mycobacteria provide diagnosis and treatment options. Initial indication of infection may be the identification of AAFB by microscopy. Culture for AAFB in the laboratory uses continuous automated bacterial culture but can take up to 8 weeks. Further identification and susceptibility testing are provided following referral to Birmingham PHL laboratory (currently the referral lab is not accredited for this test)|
|Indication||Patients who are too unwell to cough or have a peripheral lesion
on the chest x-ray may benefit from a BAL.|
|Additional Info||Please remember that tuberculosis is notifiable even on grounds of clinical suspicion alone. Selected patients might benefit from TB PCR which requires prior discussion with the microbiologist before testing.|
|Interpretation||Preliminary microscopy results will be reported negative or positive with a quantitative indication.
Initial culture results will be reported as AAFB isolated with confirmation of final identification and sensitivities reported later.|
|Collection Conditions||For initial diagnosis specimens should be fresh and where possible taken before anti-tuberculous treatment started. Other broad spectrum antibiotics such as fluoroquinolones or macrolides may also exhibit anti-mycobacterial activity so should ideally be avoided for at least 48 hours preceding specimen collection.
Performing a procedure for BAL collection for TB should be performed in a room with appropriate respiratory isolation ventilation conditions and staff should wear FFP3 masks.
Careful cleaning of instruments is required to prevent cross contamination of specimens or patients. Tap water should not be used as this may contain environmental mycobacteria species which can produce false positive results.
Please request clearly AAFB culture and microscopy on form. Samples should be marked as Danger of Infection. Do not send samples for AAFB via the airtube|
|Min. Vol||10 - 20 mL|
|Freq.||1 sample per affected bronchus|
|Ref. Range (Male)|| |
|Ref. Range (Female)|| |
|Ref. Range (Paed)|| |
|Ref. Range Notes||
|Units|| - Not Defined -|
|IP Acute TAT||See Turnaround Comment|
|IP Routine TAT||See Turnaround Comment|
|GP Acute TAT||See Turnaround Comment|
|GP Routine TAT||See Turnaround Comment|
|Turnround Comment||Microscopy for AAFB will be available within 24 hours for samples received Monday to Friday before 12pm. Microscopy TAT for samples received at weekends and bank holidays will be 3 days.
Culture 60 days
Turnaround time may be increased if prolonged incubation is clinically indicated.|
Originally edited by : Dr. H. Schuster. Review due on 14/11/2018 14:56:55. Published By K Roberts on 14/11/2017 14:56:55.