Bar graph demonstrates the epidemic curve of infectious syphilis in a north Queensland district 2009-2012 by national definition, clinician derived expanded case definition and Interim Guidelines case definition. There is a gradual increase in cases notified from the first quarter of 2010, reaching a peak in the second quarter of 2010, with a considerable drop in the last two quarters of 2012. From the first quarter of 2011, the curve is steeper and reaches a peak almost twice as high for cases identified using the expanded case definition or Interim Guidelines case definition compared with the national case definition curve.