Recurrent invasive meningococcal infections – quantifying the risk, Germany, 2002 to 2018

INTRODUCTION: Invasive meningococcal disease (IMD) is a rare condition with a high case fatality rate. While most patients suffer from one single episode in life, there is anecdotal evidence for recurrent infection. AIM: The German National Reference Laboratory for Meningococci and Haemophilus influenzae (NRZMHi) analysed IMD cases from 2002 to 2018 to retrospectively quantify the risk of recurrent infection. METHODS: Recurrent IMD was defined as detection of Neisseria meningitidis in a sample of the same patient more than 30 days after the first episode of IMD. RESULTS: Among 5,854 patients with a median observation period of 9.4 years, 14 suffered a second IMD episode and one patient a third one. The risk of a recurrent IMD was 29.4 per 100,000 person-years for survivors of the first episode. Rare serogroups (Y, W, E and Z) were more common in patients with recurrent IMD (p < 0.0001). DISCUSSION: Patients surviving IMD were at least at a 50-fold risk of another IMD episode compared with the general population. The study most likely underestimated the risk of recurrent infection. Increased risk may be due to undiagnosed complement deficiencies. The high risk of re-infection argues for vaccination of patients who have survived IMD.