Meningitis: “An unprecedented rebound” in France after the Covid epidemic

Meningococcal meningitis, potentially fatal, has experienced an “unprecedented rebound” in France after the cessation of health measures put in place during Covid-19, warned the Pasteur Institute on Tuesday, which calls for extending the vaccine to adolescents, particularly affected.

Meningitis is an infection of the coverings surrounding the brain and spinal cord. In most cases, they are viral, but can also be of bacterial origin: this is the case with meningococcal meningitis. Transmission occurs from person to person through close, prolonged contact.

Around one in ten people in the general population (but one in three adolescents) carry meningococci without any symptoms of the disease appearing. However, after infecting the respiratory tract, meningococci can spread through the body through the bloodstream.

High fever, severe headache, vomiting, neck stiffness, photosensitivity, red or purplish spots (purpura) are the main symptoms. Unpredictable and devastating, this disease can cause death in less than 24 hours, without rapid treatment. Properly treated, mortality remains 10%.

During the Covid-19 epidemic, barrier gestures such as wearing a mask and social distancing had positive consequences on respiratory infections, recalls the Pasteur Institute. This was the case for meningococcal meningitis, which saw its number of contaminations drop by more than 75% in 2020 and 2021.

Scientists have closely studied the evolution of the disease between 2015 and 2022 and observed a rapid resumption of bacterial activity. “Meningococcal meningitis experienced an unprecedented rebound in the fall of 2022, with today, in the fall of 2023, a number of cases higher than the period which preceded the Covid-19 pandemic,” summarizes Samy Taha , researcher in the Invasive Bacterial Infections Unit at the Pasteur Institute.

If 298 cases were recorded between January and September 2019, 421 cases have already been recorded between January and September 2023, an increase of 36%, “even though the winter peak has not yet occurred,” points out Pasteur. Levels “never reached” in France, underlines Muhamed-Kheir Taha, head of the National Reference Center for Meningococci.

There are two main explanations for this, according to the research institute: a decrease in general immunity following the drop in the circulation of strains, but also the drop in vaccination, which fell by 20% for vaccination. against meningococcus C during the first confinement for example.

This alarming resurgence of meningitis could increase in the coming months with the seasonal flu epidemic which creates a “favorable context for the development of meningococcal bacteria”, in particular by increasing circulation and exposure to respiratory pathogens. Another point of vigilance: large gatherings conducive to contamination such as the Olympic Games.