CDC: Flu Hospitalizations, Deaths on the Rise as Activity Increases

In today's CDC media briefing on the latest influenza activity data, CDC officials indicated that flu-associated hospitalization rates are on pace to hit record highs compared with past severe seasons.

CDC Acting Director Anne Schuchat, MD, RADM, USPHS, and Dan Jernigan, MD, MPH, CAPT, USPHS, director of the Influenza Division of the National Center for Immunization and Respiratory Diseases, provided an update on the current status of the 2017-2018 flu season. The update cited data reporting that overall influenza activity has increased over the past week, while hospitalizations and deaths continue to climb.

Influenza-related hospitalizations are at the highest that the CDC has tracked since 2010, Dr. Schuchat noted in the briefing. Overall, hospitalizations have reached a cumulative rate of 51.4 laboratory-confirmed flu-associated hospitalizations per 100,000 population.

If hospitalization trends continue, these rates will surpass hospitalizations in the 2014-2015 season, according to the briefing.

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“So far this year, the cumulative rate of hospitalizations is the highest since we’ve been tracking in this way, which goes back to 2010,” Dr. Schuchat said in the briefing. “In terms of the 2009-2010 pandemic year, it was very high for influenza activity but it wasn’t our peak for hospitalizations.”

Additionally, recent reports in the past week have indicated that activity in the western United States may be easing up, with Oregon as the one state reporting less activity. “However, we are by no means out of the woods,” she warned. Despite the possibility of relief in the west, US flu activity in the east has increased while southern states are continuing to see the same levels of high activity.

For this week, reported influenza-like illnesses have increased again, reaching 7.1% compared with the 6.6% reported in last week's briefing.

Only 2 seasons reported higher rates, Dr. Jernigan said, including the 2009 pandemic, which peaked at 7.7%.

The average flu season is typically 16 weeks, but can range from 11 to 20 weeks, suggesting that there may still be many more weeks left in the season.

An additional 16 influenza-related pediatric deaths have been reported this week, reaching a cumulative total of 53 children.

Adult mortality also increased from 9.1% to 9.7%.

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Despite reports of decreased effectiveness for the H3N2 virus, the CDC continues to recommend the flu vaccine, as other flu viruses are circulating this season as well.

References

1. 2017-2018 Influenza Season Week 4 ending January 27, 2018. Weekly US Surveillance Report. CDC’s website.https://www.cdc.gov/flu/weekly/index.htm#S6. Accessed February 2, 2018.