Bovine TB in badgers: a reappraisal of aetiology and pathogenesis.

I read with great interest the article of Miles et al. (1) about the performance of mini Wright peak flow meters after prolonged use. We performed a study (2) comparing the reliability of five new mini Wright peak flow meters before and after 10 000 compressed air impulses of about 4.50 1 min ’ flow, controlled by an electronically driven magnetic valve. There were no significant deviations of peak flow values read from the mini Wright peak flow meter before and after the 10 000 impulses compared to those controlled by a pneumotachograph. Comparing our observations with those of Miles et al., we conclude that changes in reading of mini Wright peak flow meters after 1 yr may not be due solely to multiple actuations or age of the devices, but probably also to other factors such as the influence of repeated and rigorous washing. I totally agree that checking patients’ peak flow meters after prolonged use is recommended. B. NIGGEMANN Childrens Hospital Virchow Clinic of Humboldt University Heubnerweg 6 D-14059 Berlin, Germany