Arizona flu rates are highest recorded this early in season

Arizona is seeing more influenza cases than the state has ever recorded this early in the season.

Nearly 18,000 cases have been reported so far, significantly more than the state’s five-year cumulative average for this time of year, which is 1,448, state Health Department data shows.

In comparison, 2017-2018 had a large number of reported influenza cases — 35,610 over the entire season — but only 1,865 by this time in December 2017.

“The number of influenza cases in Arizona is concerning to public health as well as the clinical health care system,” said Dr. Theresa Cullen, director of the Pima County Health Department.

Influenza will continue to make people sick through the holidays and for the next few months, she said.

“If you are vaccinated (for influenza), thank you for keeping yourself and the community healthy,” she said. “If people are not yet vaccinated against the flu, please consider getting the vaccine as soon as possible.”

Vaccine effectiveness varies, but the Centers for Disease Control and Prevention reports that flu vaccination typically reduces the illness risk by between 40% to 60% among the overall population when the virus is well-matched with the vaccine.

This year’s vaccine is working well, said Michael Worobey, who heads up the University of Arizona’s Department of Ecology and Evolutionary Biology.

“The vaccine is a good match to this season’s strains and will keep about half the people who would have ended up in the hospital after an infection healthy and protected,” Worobey said.

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The efficacy rate reported by the CDC for this year’s vaccine is about 50%. Efficacy refers to the vaccine’s ability to produce its intended result, in this case minimizing influenza infections and symptoms.

In a 2021 CDC study, it was determined that of adults hospitalized with influenza, vaccinated patients had a 26% lower risk of ICU admission and a 31% lower risk of death from the virus compared with those who were unvaccinated.

The high number of cases has brought on a national shortage of the influenza antiviral medication, Tamiflu. Cullen said the county will distribute the medication if it’s made available through the federal distribution center.

The surge in flu cases has prompted the Arizona Local Health Officers Association and hospital administrators to ask for the public’s help in reducing the spread of not only influenza, but also COVID-19 and respiratory syncytial virus, or RSV.

COVID-19 continues to be classified as high transmission in Pima County, with over 200 cases per 100,000 residents being reported in Pima County. RSV appears to be leveling off, but Cullen said it’s too soon to say whether it will continue to improve.

Emergency departments are experiencing lengthy wait times because of the spread of the flu, RSV and COVID-19, the Arizona Hospital and Healthcare Association reports.

While mild to moderate cases of flu and other respiratory illnesses can be very uncomfortable, many people can get testing and treatment at medical providers other than emergency rooms.