Burkholderia infection and survival in CF.

survival in CF We read with interest the paper by Jones et al indicating the experience of the Manchester Adult CF Unit in the survival of patients with cystic fibrosis (CF) in the first 5 years following chronic infection with the B cepacia complex (Bcc). The authors appear to have shown that 31 patients with B cenocepacia had a worse prognosis than Pseudomonas aeruginosa infected patients. Despite the title of the paper, they had insufficient patients chronically infected with B multivorans to draw any similar conclusions. Although these are not new findings, we congratulate them on their attempt to throw light on a difficult topic within the microbiology of CF. However, there are several anomalies in the study that cause concern. Firstly, they state that the 5 year survival in the B cenocepacia group was 66.6%, yet the figure (which incidentally contains data for 7 years) clearly shows the rate to be around 30%. Also, table 2 states that 19 (of 31) of these patients (61%) died within the study period, a value that fits with neither of the two previous statements. Secondly, although there were significantly more deaths in the B cenocepacia group, these patients apparently did not have increased treatment requirements or diminution in spirometric parameters compared with the matched group. This implies deterioration in respiratory function that was rapid enough to not affect the statistical calculation, but that falls short of the ‘‘cepacia’’ syndrome, which seems unlikely. We wonder whether a different statistical method may have produced more meaningful results. Finally, the authors state in the discussion that the only other studies of outcome of Bcc infection are in CF patients following transplantation. We are surprised that they appear to be unaware of the well conducted study by Ledson et al from our unit, published in this journal in 2002, which showed the outcome for 37 CF patients chronically infected with B cenocepacia, none of whom were listed for transplantation. This study used a more robust method of statistical analysis to show that B cenocepacia infected patients had an accelerated loss of lung function with a fourfold increased risk of mortality and a trend towards worsening nutrition—results in keeping with those produced by the US CF Foundation. However, we do agree with the authors that further work needs to be done to assess the effect of infection by other genomovars (including B multivorans) on morbidity and mortality in patients with CF.