Perinatal and neonatal mortality

with source traced only 13 arose from the lungs. That isolations of Pseudomonas aeruginosa have become less frequent in certain hospitals in the USA does not necessarily imply the same to be true or even likely in hospitals elsewhere-this organism was the second commonest cause of Gram-negative bacteraemia in patients with neutropenia in Addenbrooke's Hospital in the last three years. Further aspects of this article are open to similar criticism; we do not wish to labour the point, but simply to emphasise the importance for those who treat leukaemia of working in close collaboration with their own microbiological colleagues and establishing patterns of practice in conformity with their own local needs.