Increased Incidence of Non Tuberculous Mycobateria in Gloucestershire Region – Is Liquid Culture to Blame?.

According to the Health Protection Agency's report of 1995−2006, the total number of nontuberculous mycobacteria (NTM) infections has increased since 1995, concomitant with an increase in the proportion of mycobacterial lung disease due to NTM. This is in contrast to the decline in the prevalence of tuberculosis (TB). The occurrence of NTM in patients was investigated from NTM cultures from Gloucestershire Hospitals NHS Foundation Trust, and incidence and treatment of NTM was audited again the British Thoracic Society (BTS) Guidelines 2000. 65 patients were identified from a list of 88 atypical mycobacterial cultures from April 2004 to December 2007. Their notes were reviewed retrospectively using a self−generated data collection proforma.[figure1]The majority of instances of NTM were found from June 2006 onwards following the introduction of liquid culture. Most specimens (80%) were sputum. The most common organism identified was Mycobacterium avium−intracellulare (MAI) (30% of instances). The key question now is how to cope with this increased incidence. Of the 13 patients treated from this study, only 4 followed BTS Guidelines (where documented). Clinicians should be more aware of these Guidelines and build a close relationship with microbiologists to determine whether treatment is required. Laboratory reorganisation could have affected these results, and a re−auditing study will be helpful to identify the increasing trend of NTM isolates.