Early and Increased Influenza Activity Among Children - Tennessee, 2022-23 Influenza Season

Abstract

Influenza seasons typically begin in October and peak between December and February (1); however, the 2022-23 influenza season in Tennessee began in late September and was characterized by high pediatric hospitalization rates during November. This report describes a field investigation conducted in Tennessee during November 2022, following reports of increasing influenza hospitalizations. Data from surveillance networks, patient surveys, and whole genome sequencing of influenza virus specimens were analyzed to assess influenza activity and secondary illness risk. Influenza activity increased earlier than usual among all age groups, and rates of influenza-associated hospitalization among children were high in November, reaching 12.6 per 100,000 in children aged <5 years, comparable to peak levels typically seen in high-severity seasons. Circulating influenza viruses were genetically similar to vaccine components. Among persons who received testing for influenza at outpatient clinics, children were twice as likely to receive a positive influenza test result as were adults. Among household contacts exposed to someone with influenza, children were more than twice as likely to become ill compared with adults. As the influenza season continues, it is important for all persons, especially those at higher risk for severe disease, to protect themselves from influenza. To prevent influenza and severe influenza complications, all persons aged ≥6 months should get vaccinated, avoid contact with ill persons, and take influenza antivirals if recommended and prescribed.

FIGURE

Influenza-associated hospitalizations and influenza intensity thresholds among persons aged <18 years — Tennessee, 2019–20 and 2022–23 influenza seasons* * Medium, high, and very high thresholds are based on the probability distribution of peak weekly influenza-associated hospitalization rates for persons aged <18 years in Tennessee in the nine most recent seasons. The 2019–20 season is also shown for comparison because it had the highest peak rate for this age group in Tennessee in recent seasons.