Recent cases of acute necrotizing encephalopathy (ANE) and influenza-associated encephalopathy have raised concerns over the potential for severe complications following flu vaccination.
A new study published in JAMA details a case series of 41 children diagnosed with ANE across 23 US hospitals between October 2023 and May 2025. The majority of cases had no prior significant medical history, and most patients had not received age-appropriate immunization against influenza.
Symptoms included mental status changes, seizures, and focal neurologic deficits, with all patients testing positive for Influenza A subtype H1 2009 and H3. Genetic analysis revealed a gene variant in RANBP2 in 11 patients.
Management typically involved dual antiviral and immunotherapeutic strategies, including oseltamivir and intravenous methylprednisolone. However, mortality was high at 27%, with most deaths occurring shortly after admission due to cerebral herniation.
The study highlights the potential for influenza to lead to ANE even in previously healthy children, emphasizing the importance of seasonal vaccination as a preventative measure.
Meanwhile, other outbreaks have been reported, including a case of H5N1 avian flu-related encephalitis in Vietnam and a 3-year-old girl who died after contracting the virus in Mexico. A new outbreak of Nipah virus has also been reported in Kerala State, India, with 4 confirmed cases between May 17 and July 12, 2025.
Source: https://wfneurology.org/activities/spotlight-on-current-global-neuro-infections/neuro-covid-updates/neuro-id-update-august-25