Carriage of Neisseria meningitidis Among Umrah Pilgrims: Circulating Serogroups and Antibiotic Resistance.

Background: Meningococcal disease and outbreaks are a risk during mass gatherings such as the Umrah religious pilgrimage to the Kingdom of Saudi Arabia (KSA). We aimed to investigate the carriage of Neisseria meningitidis among the 2019 Umrah pilgrims and determine the circulating serogroups and their antibiotic susceptibility profiles. Methods: We conducted a cross-sectional study among adult Umrah pilgrims from 17th to 29th April 2019 in Mecca city, KSA. A questionnaire was administered to each participant, and an oropharyngeal swab was obtained. Microbiological techniques were used to isolate, identify and serogroup N. meningitidis from the swabs. E-tests were used to determine the susceptibility of the isolates to nine antibiotics. Results: The study enrolled 616 pilgrims from 17 countries with a mean age of 53.8 years (±13.1, range = 19-91) and a male-to-female ratio of 1.1:1. Nearly 39% of the respondents had no formal education, 32.5% declared having an underlying health condition and 17.2% were current or past smokers. During their Umrah stay, most pilgrims reported sharing accommodation (98.5%) and never using a face mask (98.5%). Also, 34.6% reported suffering from influenza-like symptoms and 11.8% used antibiotics. N. meningitidis was isolated from three pilgrims (carriage rate of 0.49%), two were serogroup A and one was serogroup B. Antibiotic susceptibility results were available for one isolate (serogroup B) which showed resistance to ciprofloxacin and decreased susceptibility to trimethoprim-sulfamethoxazole. Conclusion: Carriage of N. meningitidis among Umrah pilgrims was low. However, invasive serogroups were identified, including an isolate resistant to ciprofloxacin used for chemoprophylaxis. Meningococcal disease preventive measures for Umrah should be regularly reviewed and updated accordingly to reduce the risk of the disease and future pilgrimage-associated outbreaks.