Automated, laboratory-based system using the Internet for disease outbreak detection, the Netherlands

Abstract

Rapid detection of outbreaks is recognized as crucial for effective control measures and has particular relevance with the recently increased concern about bioterrorism. Automated analysis of electronically collected laboratory data can result in rapid detection of widespread outbreaks or outbreaks of pathogens with common signs and symptoms. In the Netherlands, an automated outbreak detection system for all types of pathogens has been developed within an existing electronic laboratory-based surveillance system called ISIS. Features include the use of a flexible algorithm for daily analysis of data and presentation of signals on the Internet for interpretation by health professionals. By 2006, the outbreak detection system will analyze laboratory-reported data on all pathogens and will cover 35% of the Dutch population.

Figure 1

Flow diagram showing flow and processing of laboratory data in the Infectious Disease Surveillance Information System (ISIS) and means by which signals generated by the ISIS database and the Salmonella database are created and handled. RIVM, National Institute for Public Health and the Environment, Bilthoven, the Netherlands.

Figure 2

View of Webpage listing surveillance diagnoses (“onderwerp”) flagged on week 9 of 2002. The asterisks in the columns labeled “verheffingsweek” indicate the week of sampling when the number of a particular surveillance diagnosis exceeded the threshold defined by an historical algorithm (“historische drempel”). The surveillance diagnosis for syphilis (“syphilis, vroege”) is flagged at the end of 2001 (weeks 51 and 52) and 2002 (weeks 4–9).

Figure 3

Graph showing sharp increase of weekly totals (week of sampling) of syphilis diagnoses (black line) exceeding the 99% threshold (red line). Arrow (week 9) marks when submitted laboratory reports resulted in signal generation and subsequent investigation.