The recent outbreak in the United Kingdom reignites attention on meningitis B. The numbers remain low, but the disease is unpredictable and mainly affects young people and children. From the British experience, useful indications also emerge for Italy, where vaccination remains the main prevention tool.
In the space of a few days, in a university town in Kent, in the south-east of England, they concentrated 20 cases of maeningitis B, with two deaths. Small numbers in absolute terms, but sufficient to bring the disease back to the center of European public debate. The dynamics is that already observed in other contexts: a limited cluster, which develops rapidlyprobably starting from a “social” event between students. British health authorities speak of an “explosive” episode, but cautiously avoid the term epidemic. And it is a distinction that is anything but semantic. In the United Kingdom, in fact, meningococcal meningitis remains a rare disease. In the last year they have registered approximately 378 cases in totalof which over 80% attributable to serogroup B. After the collapse during the pandemic, when social distancing had drastically reduced bacterial circulation, the numbers gradually began to rise again, approaching previous levels. The point, also underlined by British epidemiologists, is that these episodes do not indicate a generalized spread, but the ability of the meningococcus to generate sudden and localized outbreaksespecially in environments with high relational density. Universities, colleges, nightclubs: contexts in which transmission, while remaining rare, can accelerate rapidly.
Recognize symptoms (from initial to more serious signs)
One of the most insidious aspects of meningitis B is its initial presentation not very specificwhich can easily be confused with the flu or a seasonal viral infection. In the first hours, and sometimes even in the first 1-2 days, the most common symptoms are fever, general malaise, intense tiredness, headache and nausea. In some cases, vomiting, muscle pain and a widespread feeling of “strong flu” also appear. It is precisely this phase that makes early recognition difficult: at the beginning there is no obvious distinctive sign. However, as the infection progresses, the clinical picture tends to change rapidly. The most typical signs of meningitis appear when inflammation involves the meninges: neck stiffness (difficulty bending the head forward), strong sensitivity to light (photophobia), confusion or difficulty concentratinguntil marked drowsiness. Convulsions or alterations in the state of consciousness may also be associated. In the case of the most severe form, the meningococcal sepsisthe process can be even quicker. In these situations they can appear red-purple skin spots (petechiae or purpura) which do not disappear under pressure, a sign of systemic involvement of coagulation. It is a late but particularly significant wake-up call. In young children and infants, symptoms can be even more subtle and difficult to interpret: inconsolable crying, irritability, difficulty eating, drowsiness or, on the contrary, agitation. In some cases, tension in the fontanelle (the soft part of the skull in newborns) is also observed. The element that clearly emerges from the clinical literature is the speed of evolution: Meningococcal meningitis can get worse within a few hours. For this reason, beyond the rarity of the disease, the guiding criterion remains one: do not underestimate a sudden worsening of symptomsespecially if associated with neurological or cutaneous signs.
Young people and children: who is more exposed and why.
The distribution of cases follows a well-defined pattern. Meningitis B strikes most young children and young adultstwo groups that for different reasons are more vulnerable. In infants the main factor is biological: the immune system is not yet fully developed. In young people, however, social dynamics come into play: coexistence, close contact, frequent exchange of saliva, a daily life that favors, even unconsciously, the transmission of the bacterium. The British case also highlighted another element, less visible but relevant: a possibility generational vaccination gap. The meningococcal B vaccine was introduced into the UK children’s calendar in 2015. This meant that many of the students involved in the outbreak had not been vaccinated as children. It is an aspect that helps to understand the dynamics of clusters: the disease does not circulate continuously, but can find favorable terrain when two conditions meet, i.e. a population with little immunity and an intense social network. However, a central and often overlooked fact remains: meningococcal meningitis rarebut when it occurs it can evolve very quickly and seriously. It is this combination of low incidence and high severity that makes it a pathology that requires constant attention, without however slipping into alarmism.
Italy: limited numbers and the decisive role of vaccination
If we look at Italy, the picture appears more stable but not too different. Here too, serogroup B is the most frequent, especially in children, and here too the incidence remains low: approximately 0.2 cases per 100,000 inhabitants in the latest available data. After the years of the pandemic, even in our country we are observing a slow return of casesconsistent with the resumption of social interactions. The main difference compared to the United Kingdom concerns the vaccination strategy. In Italy the vaccine against meningitis B is recommended and offered to newbornswith generally high coverage in the first years of life. This has helped to significantly reduce the risk in the most vulnerable groups. However, a critical issue remains similar to that observed across the Channel: protection tends to decrease with age and is not uniform among adolescents and young adults. Precisely the categories that, in the case of clusters, may be most involved.
How meningitis B is transmitted (and why it’s not like Covid)
The first distinction to clarify is that between perception and reality. There meningitis B is not a “highly contagious” disease in the common sense of the term. The responsible bacterium, Neisseria meningitidisis transmitted through close and prolonged contactin particular through respiratory secretions and saliva. This means that contagion occurs above all in very specific conditions: kissing, sharing glasses or cutlery, living together in closed environmentsor close and continuous contacts such as those that occur between family members or in student communities. This is where the substantial difference emerges with viruses such as SARS-CoV-2, responsible for COVID-19. The latter spreads extremely easily even through aerosols and microdroplets suspended in the airmaking contagion possible even without direct contact and in a very short time. In the case of meningitis B, however, transmission is much less efficient: it’s not enough to be in the same roomnor share spaces for short periods. More intense and close contact is needed.
Daily prevention: what is really needed
If the infection requires close contact, prevention starts with simple but often overlooked behaviors. In risk contexts such as schools, universities and community environments it is fundamental avoid sharing personal items that can carry saliva, such as glasses, bottles, electronic cigarettes or cutlery. An attention that may seem trivial, but which represents one of the main transmission factors. Hand hygiene and good ventilation of rooms remain useful, but have a less decisive impact than what is observed with respiratory viruses such as influenza or Covid. This is precisely because meningitis B it does not spread easily through the air. When a confirmed case occurs, health prevention comes into play: close contacts are identified and can receive a preventive antibiotic prophylaxiscapable of drastically reducing the risk of developing the disease. It is a crucial step that allows any outbreaks to be quickly contained. And it is also one of the elements that distinguishes the management of meningitis from that of widespread viral infections: this is where the intervention is targeted and selectivenot generalized.
Meningococcal B vaccine: who should do it and why remains decisive
In adolescents, vaccination against meningococcal B is not always included in free programs, but it is recommended especially in the presence of community lifesuch as student residences or colleges. This age group, in fact, combines high sociality and uneven vaccination coverageconditions that favor possible clusters. Protection is not permanent, but can significantly reduce the risk of invasive forms.
