Mayo Clinic's Division of Microbiology will be posting weekly updates throughout this year's flu season. Look for a new update each week until the end of February.
During the fourth week of 2014, influenza activity remained high in the United States, including Iowa, Minnesota and Wisconsin. However, the Mayo Clinic Virology Laboratory is continuing to see a decline in the percentage of outpatients presenting with an influenza-like illness. This number declined for the fourth consecutive week. Key points providers should know include:
- The 2009 H1N1 influenza A virus continues to be the predominant circulating strain, and the percentage of viruses found to be resistant to antivirals continues to be very low.
- The highest rates of hospitalization due to influenza occurred in adults aged over 65 years, followed by those within the age range of 50 to 64 years old. Young children aged 0 to 4 years old account for the third highest age group requiring hospitalization due to influenza infection.
- There are several underlying medical conditions that seem to be associated with hospitalization following influenza infection. Among hospitalized adults, the most commonly reported underlying conditions were obesity, metabolic disorders and heart disease. For young children, the most commonly reported underlying medical conditions have been found to be asthma, neurologic disorders and cardiovascular disease.
Graphs and Maps
Below are some key statistics about the flu this week. Click on each image for a larger view (opens in a new window).