Meningitis: MenB strain may have evolved to be more transmissible, say experts

What has led to such a large spike in cases when compared with previous outbreaks?“This is the most fascinating question that has arisen from this outbreak,” says Emma Wall, clinical professor of infectious diseases at Queen Mary University of London. She tells The BMJ, “Meningitis A outbreaks in the Sahel [semi-arid region extending from Senegal in West Africa to Sudan and Eritrea in East Africa] can comprise thousands of cases, but MenB has never caused an outbreak of this size before.”While the UK has previously seen meningitis outbreaks caused by the bacterial strain B of meningitis (MenB), case numbers have been small—as with the two cases seen in nursery in 20231—or have occurred over many years, as happened in Gloucestershire in the 1980s.2“It’s speculation, but whether this strain has acquired the ability to spread more rapidly is something under investigation,” Wall explains. “Otherwise, I suspect this is due more to...