Carrageenan Nasal Spray and Probiotic Lozenges to Prevent Flu-Like Illness in Healthcare Workers: A Pragmatic Field Study at the Arbaeen Mass Gathering

Background: The Arbaeen pilgrimage is among the world’s largest mass gatherings and is associated with a high burden of respiratory and gastrointestinal infections. Practical, low-cost prophylactic measures suitable for crowded, resource-constrained settings are needed. Oral probiotics and nasal barrier agents may offer a feasible approach.Methods: We conducted a pragmatic, open-label field intervention study across ۱۰ health centers (Mawkibs) in Najaf, along the Najaf–Karbala walking route, and in Karbala during Arbaeen ۲۰۲۳. Healthcare workers aged ۱۶–۷۰ years received carrageenan nasal spray, Streptococcus salivarius lozenges (K۱۲/M۱۸), the combination, or no intervention (control), according to operational feasibility at each site. Self-reported gastro-respiratory symptoms (GIRS: fever, cough, sore throat, runny nose, diarrhea, vomiting) were collected by telephone on day ۲۵ to capture symptoms within the Arbaeen target period. Analyses used Chi-square/Fisher’s exact tests, Kruskal–Wallis, and age- and sex-adjusted logistic regression (two-sided p≤۰.۰۵).Results: A total of ۲۲۲ participants were included and analyzed (control n=۱۰۶; intervention n=۱۱۶: lozenge n=۱۹, spray n=۶۰, combination n=۳۷). Mean reported product use was ۵.۳۶ days. Compared with control, the combination arm showed lower odds of fever (OR ۰.۱۱۴; ۹۵% CI ۰.۰۴۵–۰.۲۹۱), cough (OR ۰.۱۸۳; ۹۵% CI ۰.۰۷۵–۰.۴۴۶), and sore throat (OR ۰.۱۷۴; ۹۵% CI ۰.۰۷۴–۰.۴۰۶). Diarrhea and vomiting were not significantly different. No serious adverse events were reported.Conclusions: In this real-world setting, combined carrageenan spray and S. salivarius lozenges were associated with lower odds of flu-like symptoms among healthcare workers. Findings are exploratory and should be confirmed in larger placebo-controlled studies.

کلیدواژه ها:

Mass gathering ، Arbaeen ، infection prevention ، Field intervention ، respiratory infection ، Travel Medicine