The Association of Acute Watery Diarrhea in Iranian Pilgrims of Iraq with Cholera Cases in Iranians

BACKGROUND: Despite the advances in the control of infectious diseases like cholera, they can potentially cause epidemics, especially in mass gathering events. One of the most important countries on the walking way of the Arbaeen religious event is Iran, which requires health system preparedness. The aim of this study was to predict the cholera epidemic in Iran by using the syndromic surveillance system of Iranian pilgrims in Iraq. METHODS: The data of the Iranian pilgrims with acute watery diarrhea in Iraq during the Arbaeen religious event and the confirmed cholera cases of pilgrims after returning to Iran were analyzed. We used the Poisson regression model of the relationship between the numbers of cases to evaluate acute watery diarrhea and cholera. Spatial statistics and hot spot analysis were used to identify the provinces with the highest incidence. SPSS software Version 24 was used for statistical analysis. RESULTS: The frequency of acute watery diarrhea cases was 2232 and the frequency of cholera in pilgrims after returning to Iran was 641. The results of spatial analysis for acute watery diarrhea cases showed a high number of acute watery diarrhea cases in the Khuzestan and Isfahan provinces, located in hot spots. Using Poisson regression, the relationship between the number of acute watery diarrhea reported in the syndromic surveillance system and the number of cholera cases was confirmed. CONCLUSION: The syndromic surveillance system is useful to predict the outbreak of infectious diseases in large religious mass gatherings.