Influenza-related complications more common in kids with neuropsychiatric comorbidities

Neurologic and psychiatric complications associated with influenza occurs rarely in the paediatric population, but such incidence can be severe and may even lead to hospitalization, suggests a study.

Moreover, children with underlying neurologic or psychiatric comorbid conditions are more likely to experience such complications than those without these conditions.

“Better recognition of these influenza-associated complications can lead to appropriate treatment along with targeted education in the clinical and public health settings,” the investigators said. “These findings emphasize the importance of mitigating influenza through prevention and vaccination efforts to prevent potentially life-altering influenza complications.”

This study involved a retrospective cohort of children aged 5–17 years with an outpatient or emergency department International Classification of Diseases, 10th revision influenza diagnosis and enrolled in Tennessee Medicaid from 2016 to 2020.

The investigators used a validated algorithm to identify serious neurologic or psychiatric complications requiring hospitalization. They then reported the incidence rates of complications expressed per 100,000 person-weeks of influenza and 95 percent confidence intervals (CIs).

Overall, 156,661 influenza encounters were included in the analysis. The overall incidence rate of neurologic complications was 30.5 (95 percent CI, 24.0–38.6). Such incidence was significantly higher among children with an underlying neurologic comorbidity, at 1,880.9 (95 percent CI, 971.9–3,285.5) per 100,000 person-weeks of influenza. [Pediatr Infec Dis J 2024;43:959-962]

For psychiatric complications, the overall incidence was 20.2 (95 percent CI, 15.1–27.0), while that among children with an underlying psychiatric comorbidity was 111.8 (95 percent CI, 77.9–155.5).

These findings on children with underlying neuropsychiatric comorbidities having a higher incidence of complications that require hospitalization are consistent with those of previous studies. [Clin Infect Dis 2020;71:e409-e414; J Pediatr 2021;239:32-38.e5]

Furthermore, antiviral treatment distribution was comparable between children with and without neurologic or psychiatric complications.

The most common neurologic complication was seizure (17.5, 95 percent CI, 12.8–23.9), while the occurrence of encephalitis was uncommon (0.5, 95 percent CI, 0.02–2.5). For psychiatric complications, the most frequent was mood disorder (17.5, 95 percent CI, 12.8–23.9) and the least common was self-harm events (0.9, 95 percent CI, 0.3–3.3).

Seizures can lead to long-term morbidity in children. Notably, a report by the Centers for Disease Control and Prevention highlights the association of cognitive impairment, development of significant anxiety or mood disorder, and other medication comorbidities with seizures in the paediatric population. [https://www.cdc.gov/flu/weekly/index.htm]

On the other hand, encephalitis, a severe neurologic complication of influenza, can progress quickly and result in death or serious neurologic impairment. [J Pediatric Infect Dis Soc 2022;11:533–540]

“Our findings reveal that neurologic and psychiatric complications related to influenza in the paediatric population are uncommon but can be severe and result in hospitalization,” the investigators said. [Eur J Pediatr 2023;182:2615-2624; Pediatrics 2024;153:e2023064800]

“These data emphasize the importance of awareness and recognition of neuropsychiatric complications of influenza in children, particularly in children with underlying neurologic or psychiatric comorbid conditions,” they added.