Flu cases are surging across the United States, leading to a significant increase in hospitalizations. According to the Centers for Disease Control and Prevention (CDC), hospitalizations nearly doubled from the previous week, rising from 9,944 to 19,053 as of December 20, 2023. The latest data reveals that flu activity is classified as “high” or “very high” in 32 states, significantly up from 17 just a week prior.
Since the start of the flu season in October, at least 7.5 million individuals have reported illness, and around 3,100 deaths have occurred. The number of pediatric deaths has also risen, with five reported this season, up from two the previous week. Doctors anticipate that flu cases will continue to rise for several weeks, with no signs of levelling off until late January or February.
Impact on Young Children and Hospital Resources
Health professionals are particularly concerned about the impact of this flu season on young children. Infants and children aged four and under have been severely affected, although school-aged children and young adults are also presenting with flu symptoms. Dr. Lauren Siewny, medical director at Duke University Hospital in North Carolina, noted that older adults and individuals with chronic conditions are more likely to require hospitalization.
The influx of flu patients has strained hospital resources. Dr. Jennifer Goebel, an attending physician at South Shore University Hospital in New York, reported an unprecedented volume of flu cases, particularly following the Thanksgiving holiday. “I don’t remember seeing flu cases this early and in this many numbers,” Goebel stated.
Dr. Donald Yealy, chief medical officer of the UPMC health system, emphasized the rise in acute respiratory infections, largely attributed to influenza. He remarked, “The biggest set of those are people with suspected influenza, and of those, it’s disproportionately influenza A.”
Dominant Strain and Symptoms of Illness
The dominant strain circulating this season is Influenza A, specifically a mutated H3N2 strain known as “subclade K.” This strain has been associated with more severe illness, contributing to the spike in hospitalizations. Although some have labeled it a “super flu,” Dr. Wenqing Zhang of the World Health Organization noted that current data does not indicate an increase in disease severity.
Symptoms of this flu variant remain consistent with previous seasons, including high fever, chills, cough, and muscle aches. Dr. Molly Fleece, an associate professor at the University of Alabama at Birmingham, pointed out that complications can be more severe, particularly for unvaccinated individuals and older adults with existing health conditions. “If patients are having shortness of breath or high fever despite taking medications, we advise them to seek medical attention,” Goebel said.
Vaccination and Other Viral Infections
Health officials stress that it is not too late for individuals to receive their flu shot, which contains a component of H3N2. While the vaccine may not perfectly match the mutated strain, it is still considered effective in preventing severe illness, hospitalization, and death. Dr. Yealy stated, “This year’s seasonal vaccine can help provide protection.”
In addition to flu, other respiratory viruses are circulating. Data from WastewaterScan, a collaboration between Stanford University and Emory University, indicates a slow increase in Covid cases, particularly in the South, Northeast, and Midwest. Norovirus infections have also spiked, and respiratory syncytial virus (RSV) is beginning to rise, especially in southern regions.
The current flu season serves as a reminder of the potential severity of viral infections, particularly when multiple viruses are present. Dr. Yealy noted, “Having one respiratory virus can worsen another condition,” highlighting the importance of monitoring symptoms and seeking timely medical care.
