Meningococcal infections in England and Wales: 1991.

There were fewer reports of cases of meningococcal infection in England and Wales during 1991 than in 1990. The number of isolates received at the Meningococcal Reference Laboratory decreased by 102 (7%), largely due to fewer strains being received from South West Thames, North East Thames and North Western regions. Group C infections showed a greater decrease than group B, with 16% fewer strains reported in 1991 than in 1990. Eight per cent of the strains received during 1991 showed reduced susceptibility to penicillin (MIC > 0.16mg/l).