Meningococcal vaccination and travel health in Hajj pilgrims : a study of pilgrims to Mecca, Saudi Arabia

Abstract

Background: Hajj brings millions of pilgrims from different countries into a confined place. A number of outbreaks of meningococcal disease have been reported after the Hajj. All pilgrims are required to receive a quadrivalent meningococcal vaccine at least 10 days before the Hajj. They are also advised to follow travel health advice to reduce the risk of acquiring infections. We conducted a study to investigate the association between time of meningococcal vaccination and carriage of Neisseria meningitidis pathogenic serogroups A, C, W, and Y. Patterns of health problems encountered by pilgrims and preventive measures adopted during the Hajj were also investigated. Methods: A cross-sectional oropharyngeal carriage survey was conducted in 2973 Hajj pilgrims in 2017. A two stage sampling method was used to select departing flights. An electronic data collection tool (‘Open Data Kit’ (ODK)), was used to gather demographic, health and exposure data through questionnaires. Real-time polymerase chain reaction (rt-PCR) was used to identify N. meningitidis and serogroups. Results: The overall prevalence of N. meningitidis carriage was 4·6%. Meningococcal carriage of pathogenic serogroups A, C, W, and Y was not significantly associated with time of vaccination. A total 22·58 % were likely unvaccinated against meningococcal disease. 38.7% reported symptoms of upper respiratory tract infections and 5.4% of travel 4 diarrhoea. Compliance with facemask use was 50.2%. Changing facemask every 4 hours was found to be a significant protective factor for URTI’s. No significant association was found between having a chronic disease and seeking pre-travel advice. Conclusion: Whilst this study did not find any association between timing of meningococcal vaccination and carriage of N. meningitidis, it did highlight the issue of unvaccinated pilgrims and a need to strengthen compliance with the current vaccination policy. Early pre-travel health advice should continue to be enforced.