While COVID-19 rampaged through the state, flu cases dramatically decreased in the 2020-2021 flu season in Illinois and Champaign County compared to last flu season.
The previous season saw 4,457 positive flu tests statewide, while only 27 people tested positive this season so far, with only four weeks remaining. Nine pediatric deaths were linked to the flu last season, and zero pediatric deaths have been reported this season. COVID has caused over 22,000 deaths in Illinois and 146 deaths in the county.
Influenza-like illnesses, commonly referred to as the flu, is defined as fever higher than 100°F with a cough and/or sore throat.
Flu activity began to decrease in mid-November 2020, according to Illinois public health officials. The previous year the activity began to spike. The lowest flu activity Illinois experienced this season was in March 2021. The flu season generally ranges from October to May.
The highest flu rate in Illinois in the past few seasons was in mid-February of 2020 at 7.4%. Compared to February 2021, there was a 93.2% decrease in flu activity, resulting in the lowest rates in the past five years.
Awais Vaid, deputy administrator and epidemiologist at the Champaign-Urbana Public Health District, said the data provided by the Illinois Department of Public Health is reliable. It is standardized for all states and counties where the Centers for Disease Control and Prevention has sentinel surveillance sites for influenza-like activity that is done every year, according to Vaid.
Vaid said last year’s flu season data were not skewed by misidentifying COVID-19 as the flu.
“When people go to see their doctors for flu-like illness, they are being tested for the respiratory panel, which includes flu as well,” Vaid said. “So, if that would have been the case, then [people] would have been diagnosed.”
Although influenza is not a reportable disease in Illinois, the public health department examines reports from health care sites statewide.
“These sites include physician offices, emergency departments, and other clinics that report acute illness with influenza-like illness, and institutional settings such as nursing homes and prisons that report outbreaks,” the website states. “Accordingly, IDPH monitors disease trends and influenza activities as they occur on a weekly basis.”
The Champaign region began to experience a decrease in flu activity in January at 1.0%. Its lowest activity rate was in March at 0.5%.
Vaid said there was one death in 2019, and three deaths in 2020 in Champaign County related to the flu.
Christopher Brooke, professor of microbiology at the University of Illinois at Urbana-Champaign, said the benefits of getting vaccinated against COVID-19 are gaining attention. He said that the flu has been controlled due to vaccination.
“The age profile of people who are dying, is starting to lower and that’s because the first people to get vaccinated were those who are most vulnerable due to age,” Brooke said. “And so we are now seeing the benefits of that and lowered mortality rates amongst, you know, older people, because so many of them have been vaccinated.”
The Centers for Disease Control and Prevention (CDC) flu vaccine distribution numbers indicate more people got vaccinated near the start of this flu season compared to the previous one. By the first week of March, around 194 million people in the U.S. got a flu vaccine this season, while only around 175 million did last season. According to CDC data, about half of the U.S. population gets vaccinated for the flu.
Vaid said continuing to social distance, using face masks and disinfecting items will help prevent both flu and COVID-19. A healthy food diet and exercise can also help, according to Vaid.
Yet, Vaid said it is to be determined whether or not the activity will remain the same for the upcoming flu season.
“If all the preventive measures that people have been taking continue, then we should see a reduction in the number of cases,” Vaid said. “The one other concern that scientists also have is viruses compete for dominance. Flu was not able to dominate this year.”