Hospital admissions linked to a potent seasonal influenza, dubbed the 'super flu', have risen sharply across the United States, with older adults and young children bearing the brunt of the surge, according to new public health data.
CDC Data Reveals Alarming Spike in Severe Cases
The latest figures from the US Centers for Disease Control and Prevention (CDC), covering the week ending January 3, show a worrying acceleration in severe outcomes. The weekly rate of influenza-associated hospitalisations jumped by 53% compared to the previous week, largely driven by the H3N2 subclade K strain. Cumulatively, hospitalisations for the season are 37% higher than the week before.
This translates to nearly 40,000 Americans being admitted to hospital with flu in a single week, a significant increase from 33,000 the prior week. The data indicates the virus is having a disproportionate impact on Americans aged over 50. Since the flu season began in October, hospitalisations in this age group have skyrocketed by 157%.
Vulnerable Groups Face Heightened Risk
The strain is proving particularly severe in care settings and among the very young. Hospitalisation rates for older adults in retirement and long-term care facilities increased by 53% in the last reported week. While outpatient visits for young children are declining, they still accounted for nearly 20% of all flu-related doctor visits, reflecting their continued vulnerability due to developing immune systems.
Tragically, the data also shows an increase in flu-related fatalities. The proportion of flu-related deaths overall rose from 0.9% to 1.9%, a 70% increase in a week. Eight paediatric flu deaths were reported in the week of January 3 alone, bringing the season's total to 17.
One of those victims was two-year-old Isaias Castillo IV from New Jersey, who died on January 6 from complications of the flu, as announced by his family. Acting New Jersey Health Commissioner Jeff Brown offered condolences and urged vaccination, stating: 'This flu season is already shaping up to be a very serious one... By getting vaccinated, we can each do our part in reducing the spread.'
Symptoms and Strain Characteristics
This season's dominant H3N2 strain is new to most people's immune systems, increasing the risk of severe, hospitalising illness. Experts warn that while symptoms mirror other flu types—including fever and cough—this variant is leading to more intense sickness, particularly in children, with reports of week-long fevers and breathing difficulties.
A case in point is two-year-old Sarah Lopez from Georgia, hospitalised for weeks after a flu infection led to a rare spinal cord inflammation called transverse myelitis. She required a ventilator and feeding tube, and though now improving, still faces rehabilitation.
Despite the rise in severe cases, some indicators suggest the peak may be approaching. The test positivity rate has begun to decline, and the number of states reporting 'very high' influenza activity dropped from 34 to 27. However, areas including New York, New Jersey, and several states across the Midwest and South remain at the CDC's highest activity level.
Health officials continue to stress the importance of recognising severe symptoms. Dr Neal Shipley of Northwell Health-GoHealth Urgent Care advised: 'If your symptoms worsen quickly, or you have trouble breathing, weakness, dehydration or symptoms that don’t improve after a few days, you should seek urgent care.'
