Headlines - Invasive meningococcal infections in France in 2012

In 2012, 559 invasive meningococcal infections (IMI) were reported, including 547 in mainland France. The estimated incidence rate, after adjustment for underreporting, was 0.94 per 100,000 inhabitants, comparable to that of 2011. The incidence rate was higher among infants under 1 year of age (9.02 per 100,000) and among those aged 15–24 (1.87 per 100,000). As in most previous years, the seasonal peak in incidence was observed in March (74 cases), with the lowest incidence in August (26 cases). The serogroup identified for 539 cases (96%) was predominantly B (68%), followed by C (18%), W (7%), Y (6%), and rarer serogroups (1%). The estimated incidence rates were 0.60, 0.16, 0.06, and 0.05 per 100,000 population, respectively. Fulminant purpura was reported in 22% of patients. The case-fatality rate was highest (8%) among people aged 50 and older and was higher for IIM C cases than for IIM B cases. Twelve clusters of cases were reported: 7 clusters of IIM B, 4 clusters of IIM C (including a cluster of 2 cases in Saône-et-Loire that was the subject of a vaccination awareness campaign by the ARS), and one cluster of IIM W. Following a significant decrease in the IIM C notification rate between 2002 and 2010 (from 0.41 to 0.13 per 100,000 inhabitants) and a continuation of this trend between 2010 and 2012 for the age groups targeted by vaccination—particularly those aged 1–14—an increase in incidence was observed in 2012 among age groups not targeted by vaccination (under 1 year and over 25 years). According to data from the EGB (general sample of beneficiaries) at the end of 2013, vaccination coverage against meningococcal C in the age groups targeted by the vaccination schedule recommendations was 50% among 1- to 4-year-olds, and then decreased in the other age groups (30% among 5- to 9-year-olds, 22% among 10- to 14-year-olds, 13% among 15- to 19-year-olds, and 3% among 20- to 24-year-olds). This vaccination coverage appears insufficient to establish herd immunity.