Bettencourt, CéliaMartins, João VieiraRamos, MarinaMachado, Rita SáSimões, Maria João2020-05-152020-05-152019-07-09http://hdl.handle.net/10400.18/6665Introduction: Since October 2002 the surveillance of invasive meningococcal disease (IMD) in Portugal includes a mandatory laboratory notification in addition to the clinical notification, which had been mandatory since 1939. The Directorate-General of Health manages the epidemiological information and the interventions. Data from surveillance is therefore the basis for prevention and control policies. Vaccination against MenC started in 2002 and, in 2006, the vaccine was introduced in the national immunization programme, aimed to children under one year of age. Since 2007 the number of invasive C strains became residual. In April 2014, the multi-component vaccine 4CMenB was introduced in the market. The aim of this study is to perform a descriptive analysis of laboratory-based surveillance of IMD from 2016 to 2018 (data from 2018 are preliminary). Methods: The case definition of IMD is in accordance with ECDC guidelines. Hospital laboratories send meningococcal isolates to the reference laboratory for genotyping, as well as negative culture clinical samples from suspected cases for lab confirmation and genotyping. Probable and possible cases were confirmed by real time PCR targeting ctrA and sodC. Groups were identified by PCR; porA, FetA and MLST characterization was performed through amplicon-based Sanger sequencing (clinical samples) or WGS (isolates). Results: In the 3-year period, 154 cases of IMD were reported (150 confirmed and 4 possible/probable). The incidence rate ranged from 0.41 cases per 100,000 inhabitants in 2016 to 0.47 in 2017 and 0.58 in 2018. Group B was the most frequent (76.2% in 2016, 62.5% in 2017 and 70.0% in 2018), presenting a large genetic diversity. The most common subtypes within B strains were P1.7-2,4, mostly belonging to cc162 and cc41/44, and P1.22,14 (13.3%), almost all belonging to cc213. Serogroup Y was the second most frequent (14.3% in 2016, 8.3% in 2017 and 10.0% in 2018), mostly belonging to cc23. Serogroups W and C represented 5.3% and 4.7%, respectively, of all invasive strains from the 3-year period. None of the patients with IMD due to MenC was vaccinated. One serogroup Z strain was identified in 2017. Conclusions: The incidence rate of IMD in Portugal has been low in the 3-year period from 2016 to 2018, under the average of incidence rate in the European countries (0.63-0.62 per 100,000 people). Group B has been the most frequent, mostly belonging to cc41/44 and cc213. It is important to continue the IMD surveillance in order to evaluate the need of policies regarding current vaccines.engInvasive Meningococcal DiseaseMeningococciEpidemiologyPortugalInfecções Respiratóriasconference object