CDC says US flu season has likely peaked

The Centers for Disease Control and Prevention (CDC) said today in its weekly influenza surveillance report that influenza has likely peaked in the United States. Last week marked the 12th consecutive week of elevated flu levels in a season dominated by the influenza A strain H3N2.

Eight more pediatric deaths

The CDC confirmed 8 more pediatric deaths last week, bringing that total to 48 children this season. Five of the deaths were in children infected with influenza B, which typically heightens its presence at the end of the flu season. As reported last week, the CDC said there are more hospitalizations for influenza-like illness (ILI) than during the same period in 2012-13, another flu season dominated by H3N2.

The hospitalization rate among children younger than 5 years is 28.8 per 100,000, up from 25.7 per 100,000 the previous week. During the 2012-13 flu season, the hospitalization rate for people in that age-group for the same week was 56.9 per 100,000.

Hospitalization rates for patients 65 and older rose again last week. The rate is now 198.8 per 100,000, up from 180.2 per 100,000 population and the highest of any age-group. The hospitalization rate for people 65 and older for the same week during the 2012-13 flu season was 170.2 per 100,000.

Through last week, the cumulative overall rate for ILI hospitalizations was 43.5 hospitalizations per 100,000 people in the United States. This compares with 39.4 per 100,000 at this time during the 2012-13 flu season.

Fewer states reporting high flu activity

According to the CDC, only 39 states and Puerto Rico are reporting widespread flu activity compared with the previous week's 43. Eight states and Guam are reporting regional activity, and 3 states plus Washington D.C. were reporting local or minimal activity.

Despite the downward trend of flu activity, the CDC still recommends that anyone over the age of 6 months who has not yet gotten a flu shot do so. The flu vaccine is approximately 48% effective this year.

More influenza B

Influenza A constituted 68.6% of positive lab samples sent to the CDC, with influenza B accounting for 31.4%. This continues the trend of more influenza B cases in the second half of the flu season. Last week, influenza B accounted for 28% of lab specimens.

Of the influenza A samples subtyped, 97.3% were H3N2 viruses and 2.7% were H1N1.

See also:

Mar 10 CDC FluView

Mar 10 CDC summary of FluView findings

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