Trend of diseases among Iranian pilgrims during five consecutive years based on a Syndromic Surveillance System in Hajj.

Background: Every year more than 2 million people depart from Iran to Saudi Arabia for Hajj ritual whichcan be faced with some different diseases. There are not much information about frequencies and trend of diseasesin Hajj. The main objective of this study was to determine the trend of prevalent diseases during five consecutiveHajj rituals among Iranian pilgrims.