A New Normal for Influenza Illness

As a new era of influenza illnesses from the coronavirus disease 2019 (COVID-19) begins, health care professionals’ approach to diagnosing and treating the virus will be shifting in the years to come, according to a session at the virtual National Association of Pediatric Nurse Practitioners 2020 Annual Meeting.

Charles P. Vega, MD, FAAFP, health sciences clinical professor at the University of California Irvine, explained the history of influenza and the many milestones achieved since 1917 in this subject area. “We are all focused on pandemics at the moment, but pandemics aren’t new to the United States or the world,” Vega said.

When differentiating the symptoms of COVID-19 from other co-circulating respiratory illnesses or allergies, Vega emphasized that influenza is best classified by the abrupt onset of symptoms that patients experience, whereas COVID-19 is less abrupt and can be specified with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or influenza swab test.

Further, although the transmission of influenza and COVID-19 are similar, the incubation period is differentiated, with a range of 1 to 4 days for influenza and a range of 2 to 12 days for COVID-19.

When looking into the future of influenza trends, Paul G. Auwaerter, MD, MBA, FIDSA, clinical director, division of infectious diseases at John Hopkins University School of Medicine, predicts that clinical practices will be challenged.

“As we move into the next respiratory season, I think testing will evolve, but this is going to be impossible to accurately distinguish on clinical grounds,” Auwaerter said.

In Auwaerter’s review of the evidence on treatment for influenza, he mentioned the 4 recommended FDA-approved drugs for influenza A + B, including neuraminidase inhibitors oseltamivir phosphate (oral), zanamivir (inhaled), and peramivir (IV), and cap-dependent endonuclease inhibitor baloxavir marboxil (oral). Further, he did not recommend 2 adamantanes, amantadine and rimantadine, due to their high levels of drug resistance to circulating influenza A and ineffective for influenza B.

With baloxavir, it is approved as a single-dose therapy for acute, uncomplicated influenza in patients aged 12 years and older who have been symptomatic for no more than 48 hours or who are at high risk of developing flu-related complications. However, it must be given within the first 48 hours of symptom onset. Further, there are limited safety data on patients with renal dysfunction and advanced liver failure and no prospective data available on hospitalized patient length of stay, according to Auwaerter.

For pediatric patients, children are at a high risk of influenza as frequent spreaders of disease, which makes immunization the best option for prevention. However, Auwaerter recommends only oseltamivir licensed for high-risk children younger than 12 years of age and both oseltamivir and baloxavir licensed for high-risk children 12 years of age and younger.

Although baloxavir is effective and well-tolerated in adolescents based on clinical studies, Auwaerter mentioned it is a new agent and requires future study due to how it sheds the virus in children with high percentage mutations.

REFERENCE

Vega CP, Auwaerter PG. Influenza Update: Advanced Practice Pearls on Treatment. 2020 NAPNAP Virtual Conference.