Dear Editor in Chief Timely response to health events such as emerging diseases and outbreaks are a major public health priority. Outbreak detection methods and algorithms as the main tools for public health surveillance systems are under the umbrella of temporal and spatial methods. “There are three different approaches which might be used by syndromic surveillance systems to examine the performances of outbreak detection algorithms including real data testing, fully synthetic simulation and semi-synthetic simulation.” The first approach, i.e. real data testing, provides the highest degree of validity. Nevertheless, surveillance data for many of disease outbreaks or bioterrorist threats are not existent.