U.S. Influenza Activity Low This Season
Pneumonia and influenza-related mortality below epidemic threshold
TUESDAY, Dec. 18 (HealthDay News) -- Since the current U.S. influenza season began on Sept. 30, activity to Dec. 1 has been low, according to an article published in the Dec. 14 issue of the U.S. Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report.
M. Patton, of the CDC's National Center for Immunization and Respiratory Diseases in Atlanta, and colleagues write that during this period, 24,897 respiratory specimens were tested for influenza in the United States through surveillance system collaborating laboratories. Of these, 559 (2.2 percent) tested positive for influenza, including 515 (92 percent) cases positive for influenza A and 44 (8 percent) positive for influenza B virus.
There was only one case involving a novel influenza A virus when an 18-month-old girl was infected with swine influenza (H1N2) and has since recovered. According to mortality data from 122 cities, pneumonia and influenza caused 6.1 percent of all deaths this season, below the epidemic threshold of 6.4 percent for the period. A related editorial stresses the importance of influenza vaccination.
"How well the current vaccine strains will match the strains that circulate this season will be determined as more strains become available for analysis," the report states. "Even in years that the vaccine and circulating strains are not optimally matched, the vaccine still provides protection against related influenza viruses."