Like Strasbourg and Chambéry, cases linked to a new variant of meningococcal B have been identified in Auvergne-Rhône-Alpes, in eastern Lyon, especially among 16-21 year olds. Rather mild, this infection can sometimes cause life-threatening meningitis or septicemia.
[Mis à jour le 21 avril 2023 à 11h00] After more than two years of low incidence, an upsurge invasive meningococcal infections (IMD or meningococcal B) was observed during the 2022-2023 season. Cases related to a new meningococcal B variant. On April 20, 2023, theRegional Health Agency (ARS) d’Auvergne-Rhône-Alpes reports the occurrence of recent cases in the east of Lyon. Most of those involved were between the ages of 16 and 21 and had attended one of these two sectors. One of the patients died and several remained in intensive care for ten days, with a risk of sequelae for some. In January 2023, 6 cases of invasive group B meningococcal disease related to the same bacterial strain occurred in Alsaceannounces the ARS Grand Est in a communicated. Five live in the Strasbourg conurbation and 1 case in the city of Colmar. In April 2022, the ARS announced cases linked to this variant around Chambery. Meningococcus B is a bacteria which can be found in the throat, and sometimes in the nose, many people say “meningococcal carriers“, particularly infants and the young children. Most of the time, this bacterium does not cause symptoms or is responsible for mild symptoms. But sometimes it can cause serious diseases like meningitis Or sepsis, potentially fatal. Moreover, in How is this bacterium caught? What are symptoms ? Does it exist a vaccine to protect yourself from it? Is it compulsory for the baby?
Definition: what is meningococcus B?
Meningococcus B is a bacterium commonly found in the throat and sometimes in the noses of several people. “A bacterium that is found in 5 to 50% of the population depending on age at the level of the nasopharynx“, specifies Dr Belenotti, an internist contacted by the Journal des Femmes in February 2021. In most cases, meningococcus B is asymptomatic and does not cause any particular illnesses. But sometimes it can trigger a serious condition called invasive meningococcal disease with complications meningitis Or sepsiswhich are potentially fatal or which can leave serious sequelae. Meningitis occurs when meningococcus infects the fluid and membranes that surround the brain and spinal cord. Meningococcal sepsis (whose most severe form is purpura fulminans) is a generalized infection of the blood and various organs, which occurs when the meningococcus spreads throughout the body. Vaccination is the only effective way to prevent meningococcus B and its complications.
What is the number of cases of meningococcal infections in France?
In France, serious meningococcal infections affect approximately 600 people per year (two thirds meningitis, one third sepsis). But during the 2022-2023 season, an upsurge in cases was observed:
► In Alsacebetween November 2022 and January 2023: 6 cases of invasive group B meningococcal disease related to the same bacterial strain occurred in Alsaceannounced the ARS Grand Est in a communicated. Five live in the Strasbourg conurbation and 1 case in the city of Colmar.
► In Auvergne-Rhône-Alpes since September 2021: 17 cases IIM linked to this new meningococcal B variant, including cases in April 2022 around Chambery and recent cases in theEast of Lyon in 2023. The 10 most affected municipalities are: in Isère: Villette-d’Anthon, Janneyrias, Anthon, Chavanoz, Charvieu-Chavagneux, Pont-de-Chéruy, Tignieu-Jameyzieu, Saint-Romain-de-Jalionas, Leyrieu and in the Rhône : Pusignan. Vaccination strongly recommended for children aged 0-2 years and young people aged 16-24 in 90 towns in eastern Lyon (list on the ARS website). As part of this campaign, the vaccine is subject to 100% reimbursement (65% health insurance and 35% mutual insurance) when purchased in pharmacies.
The rebound of IMI is not an unexpected phenomenon after two years of low meningococcal circulation. Two hypotheses can be put forward to explain this marked resurgence of IIMs, reports Public Health France in its press release of April 20, 2023:
- A higher risk of infection resulting from reduced immunity in the population having been less exposed to meningococci between 2020 and 2022 (barrier gestures, distancing)
- A more marked season in connection with the scale of the epidemics of seasonal viral infections in 2022/23, in particular infections by the influenza virus, which can lead to a risk of invasive bacterial infection (meningococci, streptococci).
Invasive meningococcal disease is a notifiable disease in France. Health professionals must inform the Regional Health Agencies, responsible for implementing the necessary management measures.
The transmission is human-to-human, that is to say from human to human, reports the Ministry of Health. Meningococcal B contamination can occur through close (less than 1 meter) and prolonged contact with a person who is a carrier of the bacteria (whether a healthy carrier or a sick person), by airway or by saliva, for example by cough Or the postillions (droplets of saliva). This bacterium does not survive in the external environment, neither on objects nor on surfaces.
At what age does it catch?
People most affected by meningococcal B are children under one year old, children between 1 and 4 years old and unprotected young adults between 15 and 24 years old.
What are the symptoms of meningococcus B?
Most often, meningococci do not cause any particular diseases. But in some cases, they can lead to an invasive meningococcal B infection which is most often manifested by:
- A fever
- Of the severe headaches
- Of the vomiting
- purpura : red and purplish spots that can appear and grow very quickly (their characteristic: they do not fade or disappear when pressed)
- Sometimes disturbances of consciousness
- A pale or even gray face
- diarrhea
- Intolerance to noise or light
- A stiff neck
- Strong body aches
- A great tiredness
- Significant drowsiness
- eye paralysis
- Seizures
When should you consult?
The action to take is to contact his attending physician in the event of the appearance of the signs mentioned above. It is urgent to contact the Emergencies (15) in the event of a very high, poorly tolerated fever or the rapid onset of purpura, a sign that the infection has spread throughout the body.
Who are the people most at risk?
- Immunocompromised people.
- People who have been in close contact with someone with invasive meningococcal disease.
- Research laboratory staff working on meningococcus.
- Travelers, under certain conditions (see with their doctor).
- The entourage of these people at risk.
What is the treatment for invasive meningococcal B infection?
According to‘Pastor Institutethe seriousness and the risk of rapid development of invasive meningococcal infections requires the very rapid establishment of a antibiotic treatment. It is done intravenously and usually needs to be taken for 4 to 7 days. In France, first-line treatment is used 3 cephalosporinse generation (cefotaxime, ceftriaxone).
What is the meningococcal B vaccine?
The vaccine mainly used for vaccination in France is Bexsero® from the GSK Vaccines laboratory, the first anti-meningococcal vaccine targeting serogroup B pathogenic strains to have obtained marketing authorization in Europe, in January 2013, indicates the High Authority for Health (HAS). It is indicated for the elderly 2 months or more and it is reimbursed up to 65% by Health Insurance within the framework of the recommendations, then by mutual insurance companies. It is a vaccine composed of several antigens found on the surface of the bacteria, which will lead to the production of protective antibodies against invasive meningococcal B infections.
In France, vaccination against type B meningococcal infections is not compulsory, but recommended (unlike the meningococcal C vaccine which is mandatory). In June 2021, HAS recommends vaccinating all infants, which constitute the age group most vulnerable to these invasive meningococcal B infections, using BEXSERO® according to the MA scheme (first dose at 3 months of age, second dose at 5 months of age and a booster dose at 12 months of age). Namely that a second vaccine – TRUMENBA® – has marketing authorization, but it is only indicated for children from the age of 10 and for the prevention of invasive meningococcal disease caused by Neisseria meningitidis serogroup B.
► The 1er February 2023, the ARS ended the vaccination campaign in the Chambéry sector, as no case linked to this variant had been detected in this area since April 2022. On the other hand, the campaign is still ongoing in eastern Lyon: the occurrence of recent cases suggests that the strain is still active in this sector. Vaccination remains strongly recommended for children aged 0-2 and young people aged 16-24 in 90 municipalities in the east of Lyon. In these municipalities, two populations at increased risk of IIM B have been identified:
- Young people aged 16-24 who reside or occasionally visit these municipalities (home, employment, studies, outings);
- Children 0-2 years old: the new variant can also be transmitted to this age group and this vaccination being integrated into the vaccination schedule since 2022.
Sources:
– New meningococcal B variant in eastern Lyon: Vaccination still highly recommended for 0-2 year olds and 16-24 year olds, Auvergne-Rhône-Alpes Regional Health Agency
– Epidemiological situation of invasive meningococcal infections in France. Update as of March 31, 2023, Public Health France
– Pasteur Institute website
– Ministry of Health
– ARS Grand Est.