a single - page questionnaire ( technical appendix ) was sent to the lead cf physician in all uk pediatric and adult cf centers identified by the principal uk cf charity , the cystic fibrosis trust , in 2009 .
results were tabulated and basic statistical analysis performed by using microsoft excel 2007 ( microsoft , redmond , wa , usa ) . because m. chelonae and m. abscessus have common phenotypic characteristics and not all samples were fully sequenced by a reference laboratory , we combined these for reporting as mabsc .
twenty - three adult and 29 pediatric uk cf centers , with 8,513 cf patients , were sent questionnaires .
responses were received from 19 ( 83% ) and 24 ( 83% ) of these centers respectively , comprising 7,122 patients ( 3,805 adults , 3,317 children ) , or 84% of the uk cf population . as expected , the prevalence of any ntm isolate was higher in the adult ( 5.0% ) than in the pediatric ( 3.3% ) population ( table ) .
fifteen adult and 17 pediatric centers cultured samples for ntm yearly ; most remaining centers tested for ntm only if there was a specific clinical indication
. the ntm pathogens most frequently cultured were the rapidly growing mabsc ( 62% of adults , 68% of children who were ntm - positive ) , followed by mac ( 28% of adults , 27% of children ) .
other species ( m. gordonae , kansasii , xenopi , fortuitum , simiae , malmoense , mucogenicum , perigrinum ) together made up 8% of the total .
wide geographic variation was noted , increasing from northwest to southeast , manifesting lowest prevalence in northern ireland ( 1.9% ) and highest in south east england ( 7.5% ) ( figure ) .
regional variation in percentage of cystic fibrosis patients in whom nontuberculous mycobacteria were isolated , united kingdom , 2009 .
nineteen of 23 adult and 24 of 29 pediatric cf centers , accounting for 7,122 of 8,513 ( 84% ) cf patients , participated in the survey .
most centers required clear clinical or radiologic deterioration in addition to positive cultures , but a significantly higher proportion of adult centers ( 42% ) than pediatric centers ( 21% ) were prepared to commence treatment on the basis of repeated culture or smear positivity alone . despite this , similar proportions of ntm - positive adults and children had received specific treatment for ntm in the 2 years preceding the survey : 44% of adults and 47% of children with any ntm isolate were treated , and 62% of adults and 70% of children in whom > 2 isolates were found were treated .
six adults and 2 children who had cf had been refused a lung transplant on the basis of persistent ntm infection .
our results differ from a 2003 multicenter us survey ( 9 ) in 2 crucial ways .
first , the overall prevalence of ntm of 4.2% during the study period in the united kingdom was much lower than the 13% reported for the study done in the united states .
this could be caused in part by lower sampling frequency , occurring annually in most uk clinics , compared with 3 times annually as reported in the us study .
the proportion of patients having > 2 positive cultures was similar : 3.9% for the us study and 3.0% for our study .
furthermore , the denominator used for prevalence estimation may have been overestimated in this study : it may have included some patients missed for annual culture ; and particularly for pediatric clinics , the denominator would include non  sputum producers ( cough swabs are normally not cultured for ntm ) .
the questionnaire we used did not specify which source documents respondents used ; therefore , recall bias may be an issue .
however , all uk centers extract and report ntm data to a national database annually .
the second striking difference between this study and the us study was that rapid - growing mycobacteria ( especially mabsc ) predominated in this survey while mac predominated in the us study .
our results are more in keeping with subsequent european and middle east prevalence studies ( 7,10,12 ) . rapid - growing mycobacteria such as mabsc
are now recognized to be of greater clinical importance in cf than mac ( 1 ) , and a recent us single - center survey ( 13 ) has shown m. abscessus to be the current dominant ntm and to be associated with evidence of clinical decline . as in previous studies , we found marked geographic variation in prevalence : olivier et al
. found higher rates in coastal centers in the united states ( 9 ) , and roux et al . found the highest prevalence in west and southwest france ( 10 ) .
the higher prevalence in the south of the united kingdom could be caused by different sampling rates , but we found no systematic difference in screening policy between different uk regions .
climatic differences are relatively small across a small temperate island such as the united kingdom .
geology could be another factor ; ntm acquisition has been linked with water from aquifers ( 12,14 ) which are present mainly in the younger rocks in southeastern united kingdom .
the varied threshold for instigating ntm treatment is perhaps not surprising in view of the lack of evidence to guide this .
although there is no clear evidence to justify treatment on positive cultures alone , some centers may have lowered their threshold in the hope that ( by analogy with pseudomonas aeruginosa ) aggressive early treatment might lead to eradication .
refusal of lung transplantation is clearly an issue and appears to affect the threshold for treatment , though the rationale for refusal by transplant centers remains controversial ( 15 ) .
this survey highlights the growing importance of ntm as a cf pathogen , the importance of routine , standardized surveillance , and the need to find out how best to manage ntm in cf .
this will require further research into environmental , microbial , and host factors influencing acquisition and disease progression of ntm in the cf population .
 incidence of pulmonary infection with nontuberculous mycobacteria ( ntm ) is increasing among persons with cystic fibrosis ( cf ) . 
 we assessed prevalence and management in cf centers in the united kingdom and found 5.0% of 3,805 adults and 3.3% of 3,317 children had recently been diagnosed with ntm . 
 of those , 44% of adults and 47% of children received treatment . 
The Study
Conclusions
None