Incidence of Influenza-Associated Neuropsychiatric Events in Pediatric Patients
Influenza infection and treatment with antivirals has been associated with a range of serious and nonserious adverse events. Among those adverse events include serious neuropsychiatric symptoms such as behavior changes, altered mental status, and more.
While increased awareness and discussion of influenza-associated neuropsychiatric events has been observed in the literature in recent years, questions remain on just how common these events are.
To examine the incidence of serious neuropsychiatric events associated with influenza in children and adolescents, researchers conducted a retrospective cohort study of 156,661 influenza diagnoses. The researchers found that the overall incidence rate was 51 per 100,000 person-weeks and that older age and risk factors for influenza complications were associated with a higher incidence rate.
Lead study author James W. Antoon, MD, PhD, MPH, answered questions about these study results. Dr Antoon is an Assistant Professor of Pediatrics and Hospital Medicine in the Department of Pediatrics at Vanderbilt University Medical Center.
Consultant360: What prompted your team to conduct this study?
James W. Antoon, MD, PhD, MPH: Influenza is a common and sometimes life-threatening illness and about 1 in 10 children get symptomatic influenza each season. Influenza is known to have many complications, including encephalitis and encephalopathy, and can also exacerbate underlying conditions. The influenza antiviral oseltamivir has a black box warning for neuropsychiatric adverse events. However, it remains unclear whether oseltamivir or underlying influenza causes these events, partly because the incidence of influenza associated neuropsychiatric events is unknown. We sought to determine the incidence of serious neuropsychiatric events associated with influenza, meaning events resulting in hospitalization.
C360: Your study found that while the incidence of influenza-associated serious neuropsychiatric events was low, the incidence varied with age and risk factors. Is this a result that surprised you? Does this result align with similar research in adult populations?
JWA: The primary findings of low incidence overall was expected. We know that influenza is generally a self-limited illness in the pediatric population. The markedly increased risk in those with underlying conditions was somewhat surprising; rates were 10 times higher in those with underlying psychiatric conditions and 100 times higher in those with neurologic conditions. Importantly, we saw neuropsychiatric events in otherwise healthy children with no underlying conditions as well.
C360: Could you discuss some of the patient populations that are at an increased risk of serious influenza-associated neurologic and psychiatric complications?
JWA: Incidence rates of serious neuropsychiatric events were highest in adolescents compared with younger children, those with a risk factor for influenza complications as defined by the Infectious Diseases Society of America (primarily those with specific underlying co-morbidities or pregnancy), and in those with underlying neurologic and psychiatric co-morbidities.
C360: What are some common pitfalls when it comes to managing neuropsychiatric events in pediatric populations, and how can these pitfalls be avoided?
JWA: I think the biggest pitfall related to this topic is prevention and early identification. Most practitioners probably do not consider neuropsychiatric events when thinking about influenza. Our study quantifies the incidence of these events in the pediatric population and allow providers to identify high-risk patients in which to counsel families or follow closely.
C360: As influenza season approaches, what are some key takeaways you can provide health care practitioners for identifying and managing influenza-associated neuropsychiatric events in pediatric patients?
JWA: Every year parents discuss with their primary care providers the risks and benefits of vaccinating their child for influenza. The risk of neuropsychiatric events from influenza should be part of that discussion. For example, the risk of serious reactions to the influenza vaccine are about 1-2 per million. In our study the risk serious neuropsychiatric events from the flu itself was about 500 per million.
Our findings are also important because the antiviral oseltamivir that is commonly used to treat influenza is very much underutilized in children, partly because of the black box warning for neuropsychiatric events. We found that the rate of neuropsychiatric events was the same for children who received oseltamivir and those were not treated. Families and providers should be aware that these events can happen just as often from influenza itself.
Reference:
Antoon JW, Williams DJ, Bruce J, et al. Population-based incidence of influenza-associated serious neuropsychiatric events in children and adolescents. JAMA Pediatrics. 2023;177(9);967-969. doi:10.1001/jamapediatrics.2023.2304.