Autor(es): Bettencourt, Célia ; Nunes, Alexandra ; VigLab-DM – Network for the Laboratory Surveillance of Meningococcal Disease ; Simões, Maria João
Data: 2023
Identificador Persistente: http://hdl.handle.net/10400.18/9054
Origem: Repositório Científico do Instituto Nacional de Saúde
Assunto(s): Invasive Meningococcal Disease; Epidemiology; Surveillance; Whole Genome Sequencing; Portugal
Backroud and aim: Surveillance of invasive meningococcal disease (IMD) is essential to monitor changes in the epidemiology of the disease and for more effective infection control. In Portugal, a surveillance system based on mandatory clinical and laboratory notifications was implemented in late 2002, with the laboratory component under the responsibility of the National Reference Laboratory (NRL) for Neisseria meningitidis. In addition, since 2017, whole genome sequencing (WGS) has been routinely implemented at the NRL as a reference typing method for IMD surveillance. This work aims to analyze both the epidemiology of IMD and the genetic diversity of Neisseria meningitidis strains during the last 11 years (2012-2022) in Portugal. Conclusion: Although the incidence of meningococcal disease has decreased over the past 11 years in Portugal, MenB meningococci are still an important cause of meningitis and septicaemia. While serogroup C IMD was rare and restricted to adults, serogroup Y IMD affected all age groups. On the other hand, serogroup W IMD has been increasing since 2017, initially in adults and later (2019) in children under 4 years of age. WGS analysis revealed a high genetic diversity among N. meningitidis isolates, especially in the population of MenB isolates. The increased circulation of MenB cc213 strains observed over these nine years is particularly important and deserves close monitoring, given the predicted low coverage of this strain by the 4CMenB vaccine [6]. In addition, the slight increase in IMD cases due to the MenW cc11 strains, previously identified as clustered into two sublineages the “Original UK” and “UK 2013” strains [7], should also be monitored, as these strains are associated with an unusual clinical presentation and a higher lethality rate compared to other IMD serogroups [8, 9]. Our results underline the need for continuous surveillance of N. meningitidis infections susceptible to changes in their pattern, in order to promptly adapt IMD control strategies in Portugal.
