LIMPACT DE LA VACCINATION ANTI-PNEUMOCOCCIQUE SUR LES MENINGITES A PNEUMOCOQUE A MARRAKECH

Introduction: Pneumococcal meningitis is a worldwide scourge in children under 5 years of age. The advent and introduction of pneumococcal conjugate vaccines has led to considerable progress in the prevention of PNO meningitis. In Morocco, a new 13-valent vaccine was introduced in February 2023 including pneumococcal polysaccharide of 13 serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) on a 4-dose vaccine schedule thus covering more serotypes and providing more protection. The objective of our study is to determine the impact of pneumococcal vaccination on pneumococcal meningitis in Marrakech and to identify new non-vaccinated serotypes. Patients and Methods: This is a retrospective and descriptive study carried out in children hospitalized in the pediatric department A at the Mohammed VI University Hospital Marrakech for pneumococcal meningitis over a period of 12 years from February 21, 2010 to December 21, 2022. Results: During this period, 140 confirmed pneumococcal meningitis cases were recorded. The mean age of the children was 3.5 years. Pneumococcal meningitis mainly affected children under 1 year of age in 46% of cases. The presenting signs of PNO meningitis in our series were predominantly acute fever, febrile meningeal syndrome and convulsions. Between 2010 and 2022, 95 strains isolated from CSF were serotyped. There was a significant regression of vaccine serotype meningitis between 2010 and 2014 and an increase in non-vaccine serotype meningitis starting in 2015. Serotypes 3,19 A, 6A were maintained between 2010 and 2022.The predominant serotypes in meningitis were serotypes 23F, 15, 19NV, 6B, 3, 19A, 11A. The evolution was marked by the occurrence of sequelae in 38% of cases, and 8% of death. Conclusion: Following the introduction of the 13-valent pneumococcal conjugate vaccine, a significant decrease in pneumococcal meningitis caused by the vaccine serotypes has been observed. However, efficacy data remain scarce warranting continued monitoring to assess the effectiveness of vaccination in improving protection against pneumococcal meningitis.