Trends in surveillance data of influenza virus in Tehran before decreasing dispatch of Iranian Hajj pilgrims to Mecca

Background: Respiratory infections, especially viral infections, are the most prevalent infection affecting Hajj pilgrims. Commonly 3 major human influenza viruses (A/H1N1, A/H3N2, and B) are responsible for these morbidities. The present study was conducted to develop a statistical report on human influenza in Hajj pilgrims.    Methods: Nasal and throat samples were collected from 232 returning Iranian pilgrims in hospitals of IUMS. All samples were kept in the refrigerator at 4 °C and stored at −70 °C until RNA extraction. RNA extraction was performed by QIAamp viral RNAmini kits (QIAGEN, Hilden, Germany) and influenza viruses were detected by TaqMan RT-PCR.    Results: Participants included 115 (49.5%) male and 117 (50.5%) female patients, with the age range of 10 to 93 years (mean: 53 years). The pandemic and seasonal influenza A (H1N1) virus were detected in 2 (0.8%) and 20 (8.6%) pilgrims, respectively, and also influenza B was identified in 1 person (0.4%).    Conclusions: Since the probability of an influenza pandemic has been anticipated for the coming years, it seems necessary to plan a continuous monitoring of large gatherings like Hajj and conduct statistical studies in the region. Moreover, material surveillance in humans needs to be boosted. Therefore, results of influenza research can be important for developing WHO reports.