Montana has seen zero influenza cases this season- largely because of COVID-19 prevention

Posted at 9:04 PM, Jan 21, 2021
and last updated 2021-01-21 23:04:48-05

BILLINGS — The state of Montana has seen zero lab-confirmed cases of influenza this season, which could be largely contributed to COVID-19 mitigation procedures like masking and physical distancing, said Nancy Iversen, Billings Clinic director of patient safety and infection control.

“Billings Clinic has not confirmed any type A or B in either any of our hospital patients or our outpatients. We do test for it. We’re not testing a lot, but that is true and even for the United States, we are not seeing the normal pattern of influenza that we’ve seen in prior years," Iversen said Wednesday.

Iversen is a registered nurse and has been doing infection prevention work for 26 years. She serves on the Yellowstone County incident management team that's handling the pandemic and served a similar roll when the community faced anthrax in the early 2000's, and later small pox and H1N1 influenza.

Montana's flu season generally begins in late November with the peak in February. During the 2019-2020 influenza season, there were 11,255 cases, 514 hospitalizations, and 41 deaths due to influenza in Montana, according to the state Department of Public Health & Human Services (source). By way of comparison, there have been 1,122 deaths in Montana due to COVID; 91,041 positive COVID cases in Montana; and 4,049 hospitalizations in Montana due to COVID since March 2020.

Over the past five years, Yellowstone County has averaged a total of five flu deaths per year, according to data presented by Yellowstone County Health Officer John Felton to the Billings City Council on Monday.

Yellowstone County data presented by the county health officer to the Billings City Council Monday night comparing the last five flu seasons to the past 10 months of COVID-19.

At the Council meeting, Felton said there are three likely contributing factors to the state's lack of flu cases. First, COVID-19 and the flu are both respiratory diseases transmitted person-to-person in the same way. Therefore, all of the protocols like masks, social distancing and sanitation have worked to slow the spread of flu too, Felton said.

Iversen said much the same, emphasizing the health officer orders requiring masking and other procedures worked as intended, to minimize the risk of infection from respiratory disease.

"For the last 10 or 11 months, part of our role has been setting policies and guidelines for people so that they are not affected or to minimize their risk. Much of the public health recommendations, including vaccination, are to reduce risk. iI’s not to eliminate risk. So we’re watching this (lack of flu). It’s just an interesting observation. None of us have seen this before," Iversen said.

Another possible reason for the state's lack of flu cases is that COVID-19 is the more predominant virus circulating in the community. Iversen said generally, the flu has a yearly cycle of traveling from the southern hemisphere north, eventually reaching Montana, but in this season, doctors haven't seen it in patients.

"It’s pretty striking. Generally influenza comes to us via the southern hemisphere and it circulates from the south generally making its way up and then across the United States," Iversen said.

The third possible reason has to do with testing. If someone has flu-like symptoms, they are encouraged to be tested for COVID-19. If the COVID-19 test comes back negative, it's likely people haven't been going back to the doctor to have them run a test specifically for the flu.

Iversen said the testing reason isn't as likely to factor into the lack of flu cases, at least at Billings Clinic. One of the hospital's testing machines looks for COVID-19, influenza types A and B and RSV (Respiratory Syncytial Virus). Of the tests ran through that machine thus far, none have come up positive for the flu, Iversen said.

"The other respiratory viruses, we’re not seeing. We are seeing an occasional rhinovirus and earlier this fall, we saw some adenovirus, which would be one of your worst colds. But for the large part, the other large respiratory viruses just aren’t circulating right now," Iversen said.

Not every COVID-19 or flu test is ran through the machine that can detect the wide range of viruses. Iversen said there are other machines that doctors can use if they suspect the patient doesn't have COVID-19.

“Certainly if we have people that have clinical symptoms or they test negative, the medical staff are very astute to look for other causes. Then we have infectious disease physicians that can be consultants to the other medical staff to really look for other causes of their potential symptoms," Iversen said.

Just because the COVID-19 vaccination has arrived doesn't mean the community can let its guard down with virus prevention measures like masking and social distancing, Iversen said. The vaccine, like the other measures, is intended to limit risk. While the technology behind the vaccine is safe, health experts don't know how long it will protect you. Iversen advocated for the community to stay the course with virus prevention and get the vaccine when it's available.

"There were really amazing scientific advances to bring us this technology messenger RNA vaccines. The vaccine is a risk reduction. Vaccines continue to limit your risk and reduce your risk. It’s not to say if I’m vaccinated, then I don’t have to do anything because people are going to respond differently to this vaccine. Some are going to be more protected than others. We definitely have a responsibility, in my opinion, to protect the vulnerable members of our community," Iversen said.

By the numbers, COVID-19 is far more deadly than influenza. In the past 10 months, COVID has killed 175 Yellowstone County residents. Compare that to the past five years of flu deaths, which total 23. That makes COVID-19 7.6 times more deadly than influenza in the county.

This is all according to data presented by Felton to the Billings City Council.

RELATED: With COVID-19 cases on decline, Yellowstone County health officer rescinds health orders