Influenza Activity Remains Sporadic Across United States

Centers for Disease Control and Prevention

Sporadic influenza activity continued across the United States in the 2021-2022 flu season, with increasing rates observed in some areas.

Data from the weekly flu update from the Centers for Disease Control and Prevention (CDC) show 4.2% of patients show 1,807 positive specimens (4.2%) from 43,078 specimens tested for the week ending February 19. The most prevalent positive specimens was once again Influenza A, making up 1,770 (98.0%) of positive tests.

The current estimates from the CDC for this flu season have been:

• at least 2.4 million flu illnesses
• 23,000 hospitalizations
• 1,400 deaths from flu

Reports from public health laboratories show a total of 366 positive specimens from 18,582 tested. The majority of viruses detected in public health labs are influenza A(H3N2). Those identified thus far are closely related genetically to the virus

Additionally, of the 7,560 influenza positive cases reported by public health labs this season and also tested for SARS-CoV-2, 456 (6.0%) tested positive for SARS-CoV-2.

The number of hospital admissions reported to the Department of Health and Human Services (HHS) Protect system has increased the past 3 weeks with 1,420 patients admitted to hospitals with influenza this week.

Meanwhile, the cumulative hospitalization rate in the FluSurv-NET system is higher than the rate for the entire 2020 - 201 season (4.9 per 100,000). However, this is lower than the rate at this time during the four seasons preceding the COVID-19 pandemic.

Further data show the percentage of outpatient visits due to respiratory illness remained stable nationally at 1.5% compared to last week and is considered below baseline. The report noted that influenza is contributing to levels of respiratory illness, while other respiratory viruses are additionally circulating.

According to the activity map, 2 jurisdictions experienced moderate activity and 0 jurisdictions experienced high or very high activity for influenza-like illness.

A single influenza-associated pediatric death was reported this week, marking it the sixth death reported this season.

The CDC noted that an annual flu vaccine is the best way to protect against flu and its potentially serious complications, recommending that every person aged 6 months and older should get a vaccine as long as activity continues. Vaccination coverage for flu has remained lower this season in comparison to the last.

The report was made available on the weekly CDC FluView resource.