The prescribing of antiviral drugs for US children and adolescents receiving treatment for influenza was less than 60% in the 2023-24 respiratory virus season, down from 70% to 86% in 2017-18, with only 31% of high-risk patients receiving the drugs, a new Centers for Disease Control and Prevention (CDC)–led study finds.
The researchers calculated rates of antiviral prescribing or receipt using data from two flu surveillance networks for children and teens receiving flu treatment during the 2017-18 to 2023-24 respiratory virus seasons.
The networks were the Influenza Hospitalization Surveillance Network (FluSurv-NET) and the New Vaccine Surveillance Network (NVSN). Antiviral treatment was defined as documentation of a prescription for or receipt of baloxavir (Xofluza), oseltamivir (Tamiflu), peramivir (Rapivab), or zanamivir (Relenza).
The findings were published yesterday in Morbidity and Mortality Weekly Report.
"Annually, seasonal influenza virus infections among children and adolescents in the United States are estimated to result in millions of medical visits, tens of thousands of hospitalizations, and hundreds of deaths," the investigators wrote. "Influenza vaccination and early initiation of antiviral treatment can reduce the risk for influenza complications."
"Prompt antiviral treatment has also been associated with lower odds of intensive care unit (ICU) admission and death among hospitalized children and adolescents with influenza," they added.
Prescribing highest for infants younger than 6 months
In the 2023-24 flu season, the research team analyzed the 573 flu-related outpatient visits and 283 hospitalizations documented by NVSN and 1,846 hospitalizations from FluSurv-NET. The largest proportion of patients in NVSN and FluSurv-NET were 5 to 11 years old (42% and 39%, respectively) and White (36% and 33%).
During the 2017-18 respiratory virus season, 70% (NVSN) to 86% (FluSurv-NET) of hospitalized children with flu received antivirals, declining to 52% to 59% in 2023-24. In the latter season, 31% of high-risk patients in this age-group seen outside of the hospital were prescribed antivirals.
Among nonhospitalized patients, the largest groups of infected children (42%) were 2 to 4 years old and Black (43%). Within NVSN and FluSurv-NET, 58% and 47% of hospitalized children, respectively, had no underlying medical conditions. Asthma or reactive airway disease was common among children in both networks and settings (21% in NVSN; 26% in FluSurv-NET).
The proportion of prescriptions (all for oseltamivir) for nonhospitalized children was highest among children younger than 6 months (49%) and lowest among those 2 to 4 years old (21%).
Among hospitalized patients, 16% (NVSN) and 19% (FluSurv-NET) were admitted to an ICU, and 7% to 13% (NVSN) and 4% to 7% (FluSurv-NET) required invasive or noninvasive mechanical ventilation. Antiviral treatment prevalence in this group was highest among those younger than 6 months (68% in NVSN; 73% in FluSurv-NET) and lowest among those 2 to 4 years old in NVSN (43%) and 12 to 17 years in FluSurv-NET (49%).
Nearly all hospitalized antiviral recipients (99%) were given oseltamivir, most of them (68% in NVSN; 60% in FluSurv-NET) received the drug on the day of admission, and 29% (NVSN) and 34% (FluSurv-NET) began therapy 1 or more days later.
Underprescribing may be due to adverse-event worries
The proportion of participants in both settings who received antivirals rose with an increasing number of comorbid conditions, from 28% of those with none to 57% among those with three or more (outpatient) and, among hospitalized patients, from 45% to 75% (NVSN), respectively, and from 55% to 77% (FluSurv-NET), respectively.
Treatment of any person with suspected or confirmed influenza who is hospitalized; has severe, complicated, or progressive illness; or is at higher risk for influenza complications should not await laboratory confirmation.
Among children with asthma or reactive airway disease, 34% were prescribed antivirals in outpatient settings, and 64% (NVSN) and 62% (FluSurv-NET) received them in the hospital.
In hospitalized participants, a higher percentage of those admitted to an ICU received antiviral therapy (84% in NVSN; 82% in FluSurv-NET), and 81% were treated on the day of or after ICU admission. Among those who received noninvasive or invasive ventilation, 89% to 94% in NVSN and 82% in FluSurv-NET were given an antiviral.
"These findings demonstrate that influenza antiviral treatment is underutilized among children and adolescents who could benefit from treatment," the authors wrote. "Antiviral treatment is recommended as soon as possible, and treatment of any person with suspected or confirmed influenza who is hospitalized; has severe, complicated, or progressive illness; or is at higher risk for influenza complications should not await laboratory confirmation."
The researchers said the underprescribing may be partially due to concerns about antiviral-linked adverse events. In its flu antiviral guidance, however, the CDC says, "Parents, if your child gets sick with flu, antiviral drugs offer a safe and effective treatment option."
"Increasing access to timely care, identifying potential barriers to antiviral treatment in the hospital setting, and increasing provider education concerning the benefits of timely treatment might lead to increases in antiviral treatment of persons who are recommended to receive it," they concluded.
