Recurrent infections in homozygous sickle cell disease

The characteristics of 214 episodes invasive bacterial infection among 176 patients with homozygous sickle cell (SS) disease were examined. Streptococ cus pneumoniae occurred in 81 episodes, Salmonella spp in 70, Haemophilus i nfluenzae type b in 30, Escherichia coli in 24, and Klebsiella spp in nine. The cumulative incidence showed that S pneumoniae and H influenzae occurre d predominantly before 5 years of age and were uncommon thereafter, Salmone lla spp increased almost linearly with age, and Klebsiella spp and E coli p redominated in patients over 10 years of age. Escherichia coli had a differ ent epidemiology-it was found in older children, almost entirely girls. Exc luding this organism from an analysis of recurrent bacterial infections, th e standardised incidence rates for second and third infections were 4.8 and 15.8 times greater, respectively, than the SS population average. This imp lies that the susceptibility: to infection is characteristic of a subgroup of patients with SS disease and that sick patients with previous bacteraemi a should be investigated early and aggressively for further infection.