farzin sadeghi cellular and molecular biology research center, health research institute, babol university of medical sciences, babol, ir iran mostafa salehi-vaziri department of arboviruses and viral hemorrhagic fevers, institute pasteur of iran, tehran, ir iran amir almasi-hashiani medical ethics and law research center, shahid beheshti university of medical sciences, tehran, ir iran mohammad gholami-fesharaki department of biostatistics, faculty of medical sciences, tarbiat modares university, tehran, ir iran reza pakzad department of epidemiology and biostatistics, school of public health, tehran university of medical sciences, tehran, ir iran seyed moayed alavian baqiyatallah research center for gastroenterology and liver diseases, baqiyatallah university of medical sciences, tehran, ir iran; baqiyatallah research center for gastroenterology and liver diseases, baqiyatallah university of medical sciences, tehran, ir iran