Internet Surveillance Systems for Early Alerting of Health Threats

Abstract

In order to gather a comprehensive picture of potential epidemic threats, public health authorities increasingly rely on systems that perform ¿Epidemic Intelligence¿ (EI). EI makes use of information that originates from official sources such as reports from national public health surveillance systems as well as from informal sources such as reports from electronic media and web-based information tools. More and more national and international public health agencies employ systematic event detection systems using informal sources (news wires, media sources or websites) on the internet to monitor the perceived threat of emerging and re-emerging infectious diseases. Such web-based event detection is the first step in ¿Epidemic Intelligence¿ systems designed to provide early warning signals to public health agencies. A number of different systems have been developed for this purpose. There is, however, still the need to emphasise some fundamental differences between the available systems and to identify the challenges that lie ahead.