Invasive meningococcal disease: completeness and timeliness of reporting of confirmed cases in Thames Valley, 2006-2007.

OBJECTIVES

Regular evaluation of disease surveillance systems is essential. This study assessed the completeness and timeliness of reporting of invasive meningococcal disease (IMD) in Thames Valley in 2006-2007.

STUDY

DESIGN

Retrospective review of two data sources used in disease surveillance: the list of notified cases to the Thames Valley Health Protection Unit (TVHPU) and the list of confirmed cases at the reference laboratory during 2006-2007.

METHODS

The datasets were compared by checking patient name, date of birth, sample date and date of onset of illness. Completeness was estimated using Tilling's capture-recapture method. Timeliness was assessed by calculating the difference between the date of admission and the date of notification to the TVHPU.

RESULTS

The estimated completeness of reporting of IMD cases was calculated as 90.5% (95% confidence interval 88.6-92.4). Thirty-six percent of cases were notified on the day of admission, 63% were notified within 1 day and 72% were notified within 2 days (range 0-36 days).

CONCLUSIONS

Timeliness and completeness of reporting of IMD was clearly suboptimal. It is critical to educate clinicians on the need to notify all suspected cases of IMD to public health authorities in a timely manner.