EDITOR,—As M R Workman and colleagues state, the high susceptibility to salmonella infection among patients with sickle cell disease remains unexplained. Because there is no evidence to link this with hyposplenism the guidelines do not refer to the problem.

Our guidelines are part of the drive to increase the education of health professionals, and A A Palejwala and colleagues' study indicates that this need is greatest in general practice. Palejwala and colleagues and Helen Howie and Ann F Bisset point out the advantages of computerised data systems. We are aware of several regional registers and acknowledge the usefulness …