Epidemiology and diagnosis of meningitis: results of a five-year prospective, population-based study.

Implementation of the advice to give penicillin prior to admission, a fall in the lumbar puncture rate and the introduction into routine use of the meningococcal polymerase chain reaction (PCR) test are factors that have led us to reassess the way meningitis is diagnosed. We examined data for the period 1994-98 from a health district of 800,000 population. Of the 355 cases of meningitis reported, 258 (73%) had either confirmed, probable or possible meningococcal disease. Only 28% of meningococcal cases had received pre-admission benzylpenicillin. The proportion of suspected meningitis cases undergoing lumbar puncture fell over the period. It was 79% in 1994 and 61% in 1998 (p < 0.001). After meningococcal PCR was introduced in 1996, 73 (68%) meningococcal cases were microbiologically confirmed, compared to 72 (48%) before 1996 (p = 0.001). In all cases, age was an independent predictor of meningitis mortality, and for meningococcal cases, age and serogroup were independent predictors. Advice to general practitioners (GPs) to give preadmission benzylpenicillin to any suspected case of meningitis or meningococcal septicaemia should be reinforced regardless of age or whether a rash is present.