Over the last few months, the medical community has warned of an impending flu season more severe than the U.S. has seen for several years. That prediction has started to materialize, with Maryland and the nation now grappling with what could be the worst season for influenza and other respiratory illnesses since the H1N1 pandemic in 2009.
“This year is unfortunately tracking to be one for the record books when it comes to respiratory illnesses in general,” said Dr. Omoyemi Adebayo, an emergency department physician at the University of Maryland Baltimore Washington Medical Center in Glen Burnie.
What’s different about this flu season, Adebayo said, is the numbers of cases and hospitalizations occurring now, in early November, match those usually seen at the peak of flu season, which typically hits between two and four months later.
This premature spike in cases and hospitalizations is starkly displayed on the Maryland Department of Health FluWatch website, where infographics show colored lines skyrocketing across virtually every measure of flu and respiratory illness since early October, when tracking started.
The positivity rate, or number of flu cases relative to tests administered, in Maryland currently stands at 25% for the week ending Nov. 5 — having shot up nearly 20 points since Oct. 8. MDH uses data voluntarily reported by providers.
A 25% positivity rate is “significantly high,” said Adebayo, especially considering rates of just 5% to 6% were benchmarked to trigger COVID-19 precautionary measures, such as masking, earlier in the pandemic.
During the last comparable flu season, between fall 2019 and spring 2020, this same percentage of positive cases was not reached until mid-December. (Flu seasons over the last couple of years have generally been mild, due to large-scale masking and other precautions taken during the COVID pandemic.) The positivity rate peaked at 34% in early February of that same season.
One hundred and seventy three people are hospitalized for flu statewide, per the most recent data, and that number is in line with what is typically seen months later, at the peak of flu season, said Adebayo. No flu-associated deaths in either adults or children have been reported yet this season.
The current percentage of respiratory illness-related outpatient visits in Maryland — 7% of all visits for the week ending Nov. 5 — was not reached until late January of the 2019-2020 flu season, while emergency department and urgent care visits reached current levels (also about 7%) in late December that same season.
The reasons behind the early surge in flu cases are multifaceted, Adebayo said, and “it’s going to be very difficult to pin down any particular thing.”
While the lack of masking certainly contributes to the spread of respiratory illness, he says, the absence of a corresponding surge in COVID-19 cases — beyond some expected uptick with the cold weather — suggests that other factors may be more important. Natural viral mutations that occur across years can result in more contagious strains, Adebayo said, leading to unusual spikes in terms of severity or timing, such as the one the country is currently facing.
Chase Cook, acting director of communications for the state health department, said the agency has responded to the current surge by “urging Marylanders to practice basic health hygiene and to get vaccinated” and by launching a webpage dedicated to Respiratory Syncytial Virus, or RSV — another respiratory illness primarily affecting children that has made headlines for filling up pediatric hospital beds around the country.
Gov. Larry Hogan has also directed hospitals to use $25 million in newly allocated funds to increase staffing and available beds, Cook said.
Adebayo agrees that the trajectory of current outbreaks will be determined in large part by the public’s behavior over the next few months, including such routine practices as handwashing and staying home when sick. Vaccination is also key, he said, noting the assumptions of many of his patients that flu season would occur months down the road has led some of them to postpone getting the shot. They end up contracting flu and visiting the emergency department as a result.
“I think that if more people were to get themselves vaccinated, there is great opportunity to decrease or plateau” the rise of influenza cases, Abedayo said.
The state flu vaccination rate in Maryland is currently 21%. Among counties, Howard has the highest vaccination rate at 29%, with Baltimore County at 22% and Baltimore City at 18%.