Comparison of Viral Respiratory Pathogens Circulation Among Iranian Pilgrims During Two Large Religious Mass Gatherings: The Hajj and Arbaeen Walk 2025 Publisher



Ahmadi A S ; Zadheidar S ; Jamalvandi T ; Saadatmand F ; Shafiei Jandaghi N Z ; Moradi G ; Nasehi M ; Yavarian J
Source: Tropical Diseases, Travel Medicine and Vaccines Published:2026

Abstract

Background: The Hajj and Arbaeen walk pilgrimages are significant religious mass gatherings (MGs) among Muslims. Respiratory tract infections (RTIs) remain a major concern during such events. This study aimed to evaluate the prevalence of respiratory viral infections among Iranian pilgrims during the 2025 Hajj and Arbaeen walk. Methods: Throat swabs were collected from 110 symptomatic Iranian pilgrims returning from these MGs. Molecular techniques were used to detect respiratory viruses. Results: A total of 60 Hajj pilgrims and 50 Arbaeen walk pilgrims, with an age range 8 to 82 years for the combined groups, participated. Rhinovirus was the most common virus detected among symptomatic pilgrims in both MGs. Notably, the rate of SARS-CoV-2 infection was 1.7% in Hajj pilgrims and 32% in Arbaeen pilgrims. Co-infections of rhinovirus and SARS-CoV-2 were identified in 8% of Arbaeen pilgrims. Additionally, coronavirus OC43/HKU1, influenza A (H3N2), and influenza B virus were detected at low frequencies. No cases of MERS-CoV were found among the 2025 Hajj pilgrims. Conclusion: These findings provide preliminary data on the circulation of respiratory viruses during religious MGs in 2025. Continued surveillance is essential to reduce respiratory infection risks during such mass gatherings. © The Author(s) 2026.