Risk factors for meningococcal disease in children and adolescents: a systematic review and META-analysis.

Invasive meningococcal disease (IMD) remains a major cause of mortality and morbidity in children worldwide. A systemic review in PubMed and Cochrane Controlled Trials Register was performed for articles on risk factors for IMD in children and adolescents published during a 20-year period (19/09/1998 to 19/09/2018). Inclusion and exclusion criteria were established and applied. The data were meta-analyzed using random-effect model and the results were presented on forest plots separately for each risk factor. We identified 12,559 studies (duplicates removed). Titles, abstracts, and full texts were screened and finally, six studies (five case-control and one cohort study) were included in qualitative synthesis, five in meta-analysis. The median age of meningococcal disease (MD) cases was 72.2 months (0-19 years). Household crowding, smoking exposure, close relationships, and recent respiratory tract infections conferred a more than twofold risk for IMD in exposed individuals compared to controls [overcrowded living OR 2.52 (95% CI 1.75-3.63), exposure to smoke OR 2.10 (95% CI 1.00-4.39), kissing OR 2.00 (95% CI: 1.13-3.51), and recent respiratory tract infection OR 3.13 (95% CI 2.02-4.86)]. Attendance of religious events was associated with a decreased risk [0.47 (95% CI, 0.28-0.79)].Conclusion: Our review highlights the importance of individual characteristics as risk factors for IMD in childhood and adolescence. Preventive policies may consider individual as well as social-environmental factors to target individuals at risk.What is Known:• Close relationships, household crowding, and recent respiratory tract infections are major risk factors for IMD.• Passive smoking is a major risk factor for IMD.What is New:• Intimate kissing, household crowding, and passive smoking were found to double the risk of IMD.• Recent respiratory tract infections almost tripled the risk for IMD.