Influenza and COVID-19 cases are spiking, raising concerns about a potential respiratory disease outbreak this fall.
Health authorities are reviewing their response strategies as flu cases among children aged 7-12 have nearly doubled in a week, while COVID-19 hospitalizations have surged by almost 80% since schools reopened.
According to the Centers for Disease Control and Prevention’s (CDC) Week 35 (August 23-29) surveillance report released on September 4, the rate of suspected flu cases at outpatient clinics jumped to 13.3 per 1,000 patients, a 44.6% increase from the previous week’s 9.2. This figure is more than double last year’s rate (6.4) and exceeds the previous season’s epidemic threshold of 9.1.
The flu virus detection rate also rose to 12.3% from 10.0% the week before. Over the past month, the patient rate has steadily climbed from 7.0 to 13.3.
The surge is particularly pronounced among school-age children. In Week 35, the patient rate for 7-12 year-olds hit 36.5, the highest of any age group, followed by 1-6 year-olds at 22.6. The rate for 7-12 year-olds more than doubled from 18.1 to 36.5, while 1-6 year-olds saw a 49% increase from 15.2 to 22.6.
Hospitalizations are also on the rise. Flu-related hospital admissions jumped 82% from 89 to 162, with 22 patients admitted to major medical centers.
COVID-19 cases are following a similar upward trend. Hospital admissions for COVID-19 increased by 78.7%, from 61 to 109 in a week. Over the past month, hospitalizations have risen steadily from 48 to 109. The number of patients in major medical centers remained stable at 13.
The COVID-19 detection rate also inched up to 11.7% from 11.3% the previous week. Over the past month, detection rates have shown a consistent increase from 5.7% to 11.7%. Samples tested at five specialized facilities nationwide showed a higher detection rate of 6.0%, up from 3.4% the week before.
The CDC noted that this simultaneous increase in flu and COVID-19 cases isn’t unique to the U.S. Dr. Lee, head of the CDC’s Infectious Disease Management Division, stated that while it hadn’t seen clear evidence of both diseases rising together in other countries until last week, it’s now observing similar trends in neighboring countries like China and Japan.
He added that in Japan, some experts suggest the flu season has started about a month earlier than usual, mirroring the experience with summer outbreaks of both COVID-19 and flu.
Given the concerning spread, health authorities are initiating joint inspections with relevant departments. On September 8, the CDC will host the 9th joint response meeting with the Department of Health and Human Services, Department of Education, Food and Drug Administration, and field experts to assess the situation and review response strategies for both influenza and COVID-19.
Dr. Lee noted that while this joint meeting is earlier than usual for flu season, it needs to discuss the response strategies given the current spread.
The CDC will launch its national flu vaccination campaign for the 2026-2027 season on September 21. Free vaccines will be available for children aged 6 months to 14 years, pregnant women, and adults 65 and older.
This season, the vaccination program for children has been expanded to include 14-year-olds, up from the previous limit of 13. Adults 65 and older can receive their flu shot on the same day as their COVID-19 vaccine, starting October 12, with the CDC recommending simultaneous vaccination.
Dr. Lee advised that if you have the flu, wait about two weeks after your symptoms improve before getting vaccinated. Even though the outbreak has started earlier this year, the peak typically occurs around year-end, so vaccination is still highly beneficial.