Respiratory Carriage of Methicillin-Resistant Staphylococcus aureus-Encoding Gene in Hajj Pilgrims.

OBJECTIVES: To assess the carriage of methicillin-resistant Staphylococcus aureus-encoding genes (MRSA) among French Hajj pilgrim cohorts. METHODS: A prospective cohort study was conducted on pilgrims from Marseille during the 2014 to 2018 Hajj. Respiratory samples were collected before and after the pilgrimage. S. aureus and then MRSA-encoding genes were identified using real-time PCR. RESULTS: A total of 606 pilgrims were included with a sex ratio of 1:1.3 with a median age of 61 years (interquartile = 56-66 years, range = 21-88 years). A total of 511/606 (84.3%) pilgrims presented at least one respiratory symptom during their pilgrimage. Cough was the most frequent symptom occurring in 76.2% of pilgrims, followed by sore throat (57.6%), rhinitis (54.6%), and voice failure (36.3%). 87 (14.4%) were positive with S. aureus before travelling. On return, 130/606 (21.4%) participants were positive. The acquisition rate of S. aureus was 13.0% (79/606). The prevalence of MRSA pre- and post-travel and acquisition rate was 4.1% (25/606), 10.6% (62/606), and 8.2% (50/606), respectively. All MRSA were positive with mecA gene. No case was positive with mecC. CONCLUSION: Our study highlights the importance of surveillance and infection control measures during mass gatherings such as the Hajj to mitigate the spread of infectious pathogens, including antimicrobial-resistant bacteria like MRSA. Further research is warranted to elucidate the specific factors contributing to S. aureus and MRSA transmission during the pilgrimage and to inform targeted interventions aimed at reducing the burden of MRSA infection among pilgrims.