Health systems across multiple American states are grappling with a severe influenza outbreak, described by doctors as one of the worst seasons they have ever witnessed, driven by a so-called 'super flu' strain.
Record-Breaking Hospitalisations in Key States
The situation is particularly acute in Colorado, where the week ending December 27 saw 831 residents hospitalised with the flu – the highest number recorded in two decades of tracking. Although there was a 12% decline in the week to January 3, figures remain elevated compared to the same period last year. Approximately one in four flu tests in the state returned positive that week.
According to the latest Centres for Disease Control and Prevention (CDC) data, Colorado is one of 14 states experiencing the agency's highest level of flu activity, classified as 'very high' or level 13. This group includes New York, New Hampshire, Massachusetts, New Jersey, Ohio, Michigan, Missouri, Tennessee, the Carolinas, Georgia, Louisiana, and New Mexico.
California's Battle with the H3N2 'Super Flu'
California is facing parallel pressures, with health officials confirming the presence of the H3N2 subclade K variant, termed 'super flu'. Statewide hospitalisations have increased, with a current rate of four per 100,000 people, up from three per 100,000 the previous week. In the week to January 3, 15% of influenza tests were positive.
While this marks a drop from last year's peak, viral activity is still listed as 'high' by the CDC. Tragically, California reported its second paediatric flu-related death of the season last week, an unvaccinated adolescent from San Mateo County.
Dr Monica Gandhi, an infectious disease specialist at the University of California San Francisco, warned that cases in California may continue to rise due to holiday gatherings and subsequent incubation periods.
National Picture and Severe Patient Impact
Nationally, the CDC reports a significant surge. Weekly flu hospitalisations jumped by 53% in early January, from 31.3 to 54.1 per 100,000 people. The cumulative seasonal hospitalisation rate also rose 37% to 40.6 per 100,000.
Medical professionals on the front lines are sounding the alarm. Dr Jean Hoffman, an emergency medicine physician at the University of Colorado, wrote, "In my 18 years of practicing clinical medicine, this year is one of the worst I have seen." She attributed record emergency department visits partly to the flu, noting this strain is causing not only respiratory symptoms but also vomiting and diarrhoea, making patients feel "much worse."
The severity is starkly illustrated by cases like two-year-old Sarah Lopez from Georgia. Hospitalised with flu, she later developed a rare spinal cord inflammation called transverse myelitis. She required a ventilator and feeding tube and, though improving, now faces rehabilitation.
Experts attribute the severity to a dominant strain that is new to most people's immune systems, increasing vulnerability. The annual flu vaccine remains the best defence, with an efficacy typically between 30% and 75%. As of mid-December, 42% of American adults had received their seasonal jab.
