SALT LAKE CITY – Flu rates in Utah and the United States remain low, a trend seen a few months ago in the southern hemisphere of the world.
Although flu infections are low, COVID-19 cases across the country continue to rise, with at least nearly 1,000 reports daily in Utah since late September.
For some, the numbers don’t make sense: if public health measures protect people from the flu and COVID-19, why do new coronavirus cases and such low flu cases increase?
The answer is really simple, according to Intermountain Healthcare’s infectious disease specialist, Dr. Eddie Stenehjem.
“You had little flu in the United States, you had everyone wearing masks, you had social distances, and you had high (flu) vaccination rates,” Stenehjem said in a Questions and Answers this week. “We really hope this allows us to get out of the flu season without seeing any significant flu activity.”
As for why COVID-19 cases have not dropped? This is what Stenehjem said.
The new coronavirus is more contagious than the flu.
Scientists use a mathematical term called R0 (pronounced R-naught) to indicate how easily a disease or virus spreads from person to person in a community.
Experts have calculated that the average R0 of COVID-19 ranges from 2 to 4, which means that an infected person can spread the disease to two or more people, according to the World Health Organization in a June report. In comparison, the mean R0 of influenza in the 1918 Spanish flu pandemic was approximately 1 to 2, according to an article published in BMC Medicine.
The number can vary widely even between different areas and states and depending on the outbreak.
R0 is fluid and does not present a complete picture of how contagious it is a disease, but it does provide a starting point, despite its many limitations. One thing, however, is clear: COVID-19 is more contagious than the flu.
I was already in the community
COVID-19 has been spreading to communities since spring, meaning when winter came, the virus was already widespread, Stenehjem explained.
The flu, on the other hand, is usually carried to a community in the southern hemisphere. But with low flu cases, he never got here, he said.
This time last year, Intermountain saw between 80 and 100 cases of flu a day. This year, the health system has only reported a handful of cases in recent months.
Intermountain hospitals are actively looking for flu cases with comprehensive testing, Stenehjem said.
“It’s not for lack of a look, it’s that we don’t see flu,” he said.
The Utah Department of Health keeps track of flu cases in the state, and as of the week of Dec. 13-19, cases remained low. So far this flu season, which began in early October, a total of seven people have been hospitalized with the flu.
“We don’t really see many other viruses circulating in Utah,” Stenehjem said. “COVID-19 is by far the most important respiratory viral infection we are seeing here in Utah.”
We do not have a population vaccinated against COVID
In recent weeks, vaccines against COVID-19 are being rolled out across the state for those eligible to receive it in the first phase, but the population is not even close to herd immunity.
Influenza vaccines, on the other hand, have largely been developed across the country.
U.S. Centers for Disease Control and Prevention reported that 192.3 million doses of influenza have been distributed since last week and it is possible that up to 198 million doses may be distributed during the 2020 season. 21. These figures increase significantly compared to 2019, where 174 million were distributed over the 2019-2020 flu season.
According to the Utah Department of Health, several age groups appeared to have a higher number of flu vaccines this year compared to last year.
However, it is important to note that some age groups did not follow the pattern and reported a lower number of flu vaccinations than in 2019, such as the 6-4 year age group.
Overall, flu vaccines across the country appear to have increased over the past year, which Stenehjem said contributes to low flu.
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Lauren Bennett