A large study in the UK concludes that the incidence of complement abnormalities is so low that screening all children after meningococcal disease (MCD) is unnecessary, contradicting the blanket screening advocated in some paediatric textbooks. The researchers also say, though, that testing is warranted when children have had previous suspicious infections, complications of infection, infection with unusual meningococcal serogroups, recurrent infections with Neisseria, or have coexisting autoimmune or connective tissue disease.

Out of nearly 300 survivors of MCD tested for classical and alternative complement components, only one child, aged 4 years, showed a deficiency—in C2. She had MCD with a complicated course—septicaemia with Group B meningococcus, disseminated intravascular coagulation, and coexistent bacterial and viral infections— and a made slow recovery. When 4 months old she had had a pneumococcal infection and while convalescing had contracted a respiratory syncytial virus infection. None of her immediate family were prone to recurrent infections or autoimmune disease.

The study was based on an unselected series of 824 children known to the Regional Paediatric Infectious Diseases Unit or the Paediatric Intensive Care Unit Retrieval Service in North East region between 1996 and 1999 with suspected or confirmed MCD. In total, 212 of 352 children with laboratory confirmed MCD and 85 of 96 with clinically diagnosed MCD were tested for components of the classical and alternative complement pathway at a review six to eight weeks after discharge.