The state of Idaho and the nation have settled into what has historically been the peak of flu season, bringing numbers that health officials have described as being more similar to flu numbers observed prior to the onset of the COVID-19 pandemic.

According to Idaho Department of Health and Welfare (IDHW) data, the predominant strain in Idaho is influenza A, with south and central Idaho reporting very high and high influenza activity, respectively. Though north Idaho’s flu labels have been labeled as “minimal” to this point, Idaho State Epidemiologist Dr. Christine Hahn said the expectation is for flu activity across the state to “catch up” with the regions seeing higher infection rates today.

IDHW data also shows emergency department and urgent care visits are slightly elevated compared to this time last year, with influenza accounting for 11.5 percent of these visits compared to 10.1 percent last year. As for health care visits, influenza accounts for 8.6 percent of these visits across the state as of Jan. 3. Hahn noted that other respiratory diseases, including respiratory syncytial virus (RSV) and COVID have been relatively “quiet” to this point, accounting for 0.2 percent and 2.5 percent of health care visits across the state in the same period.

Hahn said what we’re seeing now is influenza “reclaiming its spot” among respiratory illnesses after more limited caseloads in 2019 and 2020, around when COVID-19 was first circulating in the U.S.

According to the U.S. Centers for Disease Control and Prevention (CDC), influenza illness was particularly high around the 2017-2018 season, with an estimated 45 million people falling ill with influenza and 79,400 dying from the disease. This contrasts sharply with the 2020-2021 flu season, when the CDC reported flu activity as being the lowest since reporting began in 1997 with an estimated 11 million flu illnesses.

Influenza numbers today are more similar to what they have been in seasons prior to COVID and in the week ending Dec. 27, the CDC classified the season as being “moderately severe” based upon the number of influenza-like illness visits, flu-related hospitalizations and the number of deaths resulting from the flu seen nationwide. The CDC currently estimates there has been at least 15 million illnesses, 180,000 hospitalizations and 7,400 deaths from flu to this point in the season, which typically peaks between December and February and tapers off in March.

The reason for this return to pre-COVID numbers is not necessarily known, but Hahn said a number of COVID-era practices, such as social distancing, masking and heightened immunization rates may have contributed to the more muted influenza seasons surrounding the past pandemic.

Dr. Jessica Kroll, Saint Alphonsus Medical Group’s urgent care medical director, said across the past dozen flu seasons, this year is consistent with what she described as the virus’s “cyclical” nature that would bring more significant case loads about every five years, often resulting from more virus mutation through the season.

Regardless of the cause, southwest Idaho is feeling the impact of the flu season in terms of case numbers.

In a Wednesday release, Dr. Ann Weiss, clinical director for Primary Health Medical Group, described the state as having an “explosion of flu in recent weeks,” with the southwest Idaho medical group seeing 525 weekly cases around the first of this year. For the greater Treasure Valley, influenza positivity test rates have neared 50 percent and wastewater levels are also high for influenza A, the release said.

“Within the regions St. Luke’s serves, we are predominantly seeing cases of influenza A, with confirmed infections rising sharply in early December,” Christine Myron, a spokesperson for St. Luke’s medical system, said in an emailed statement. She added the health centers’s clinics have been observing “gastrointestinal symptoms and dizziness, features that differ somewhat from what we’ve seen in recent flu seasons.”

Myron noted, however, that what the health system is seeing is not a clear uptick in the severity of cases this year.

As is the case with past flu seasons, those most susceptible to the virus are the young, pregnant women and the elderly and the proven preventive measure to avoid more severe instances of the disease continues to be the flu vaccine. Prescription options such as Tamiflu can also help decrease the duration of the illness, Kroll said.

With past experience in emergency care and current work in urgent care, Kroll underscored health clinics frequently see complications stemming from a depressed immune system often met with people not eating or drinking as much. Anyone who doesn’t get better within seven days, or starts to feel worse, should seek emergency medical care for a reevaluation, especially if breathing issues or fatigue introduce themselves after infection.

“My biggest thing, that I really try to emphasize to people is, you know, whether it’s this year, next year, five years from now,” Kroll said, “It’s always bad that people die, you know, from a virus that we have a vaccine for.”