Epidemiology of invasive meningococcal disease and its sequelae: a population-based study in Italian primary care, 2000-2019.

ABSTRACT

BACKGROUND: Invasive meningococcal disease (IMD) is a severe infectious disease. Although effective preventive and therapeutical strategies are available, the fatality rate remains high in the general population, with an occurrence of meningococcal-related severe sequelae involving 10-20% of survivors. Given the crucial role of general practitioners in recognizing and preventing IMD and its related sequelae, we aim to assess the burden of these conditions in primary care. METHODS: Using an Italian primary care database, the incidence rate of IMD was calculated in the period 2000-2019 by capturing the first diagnosis registered during follow-up. As far as meningococcal-related sequelae are concerned, we identified and clinically evaluated each potential sequela during the first 3 months, from 3 to 12 months, and up to 36 months. RESULTS: Among 508 patients diagnosed with IMD, 403 (incidence rate 0.24 per 10,000 person-years) comprised those diagnosed with IMD in patients aged 15 years or older. We ascertained 104 sequelae (20.4%); 76% of them occurred in those aged 25 or older; 42, 27, and 35 were assessed as short-, medium-, or long-term sequelae, respectively. Overall, 4.7% of IMD patients reported physical sequelae, while 12.2% and 5.7% of patients reported neurological and psychological sequelae, respectively. CONCLUSION: Our study showed that a substantial proportion of IMD and related sequelae occur in individuals aged over 25, with a non-negligible burden for healthcare systems. As for the paediatric population, effective communication on the relevance of meningococcal vaccination in adults should be proficiently fostered.