Trends in viral meningitis hospitalisations and notifications in the North Eastern Health Board (1997 - 2001): a cause for concern?

This study aimed to compare trends in both hospital admissions and notifications of viral meningitis in the North Eastern Health Board (NEHB). Hospital admissions from 1997 to 2001, involving NEHB residents with an infectious disease diagnosis, were examined and viral meningitis cases were analyzed. During this period 265 NEHB residents were admitted to hospital with viral meningitis--an increase of 429% between 1997 and 2001 with the bulk of this increase during 2000 and 2001. A total of 1,234 bed days were taken up by this cohort and the mean length of stay was 4.5 days (95% CI 4.2 - 4.9). The number of viral meningitis notifications in the NEHB was 38 (ranging from 4 in 1997 to 11 in 2001). This number is much lower than expected given the corresponding number of hospital admissions for the same period. Thus, most cases were not notified which means that current surveillance systems under-estimate the disease burden of viral meningitis. Such under-reporting has implications for infectious disease policy in Ireland.