Of the 1,528 people hospitalized during the 2012-13 flu season, about 40 percent were people aged 65 and older, according to data collected by the Colorado Department of Public Health and Environment.
“We know seniors don’t benefit as much as we would like from immunizations, due to their naturally weakened immune systems,” said Dr. Rachel Herlihy, interim deputy director for the department’s Disease Control & Environmental Epidemiology Division. “Despite this, it is critically important that seniors get vaccinated against influenza because research shows the flu vaccine is highly effective in preventing severe illness, including hospitalizations among seniors.”
Five Colorado children died during the 2012-13 flu season, with four of the five children either unvaccinated or only partially vaccinated. This mirrors national data showing 90 percent of pediatric deaths were among unvaccinated children. The five pediatric deaths in Colorado were the most since the 2009-10 flu season, when there were 12 pediatric deaths. That flu season was particularly devastating due to the H1N1 pandemic.
The 1,528 flu-related hospitalizations that occurred in Colorado (between Oct. 7, 2012, and May 11, 2013) represented the highest number of hospitalizations since reporting began in the 2004-05 flu season – with the lone exception of the 2009-10 pandemic flu season. By comparison, there were 543 hospitalizations during the mild flu season Colorado experienced in 2011-12.
The 2012-13 flu season began unusually early, with hospitalizations peaking during the week of Dec. 29. Flu seasons typically don’t peak in Colorado until well after New Years. The flu season started with a dominant B type of flu, but ended with an A type being dominant. Both types of influenza can cause hospitalization and death.
The influenza virus getting the most attention now is the avian H7N9 virus that has caused 131 human cases and 36 deaths in China. Human infections with this new virus have declined in the last few weeks, with no new cases reported since May 17. Most patients had contact with infected poultry or contaminated environments prior to their illness. Sustained person-to-person transmission of the H7N9 virus has not been identified. No cases of H7N9 outside China have been reported. The new H7N9 virus has not been detected in people or birds in the United States.
Click here for more information about influenza and to view the weekly Colorado flu surveillance report.