A report from the Center for Disease Control and Prevention (CDC) shows that influenza is still persistent despite the winter season is going to end soon. It is not eliminated completely, however, its severity is low these days. CDC added in the report that the indicators used for tracking the flu activity still show high values. The rate of flu activity fell during the first two weeks of January, but it again increased in the last three weeks of the month. Indicators for tracking the overall severity i.e. hospitalization and deaths do not show a high rate at this point of the season.
Every year 22 million people got sick due to influenza, 210,000 admitted to the hospitals and 12000 died due to flu. A recent clinical observation says that the percentage of respiratory cases tested positive for influenza rose from 28.4% to 28.8%.
A strain of virus known as influenza B/Victoria viruses prevailed during the earlier days of this season. However, recently the other strain of virus influenza A (H1N1) pdm09 viruses predominate. Now the two strains are equally present during this season. Different strains predominate among different age groups.
According to a report during this season, the influenza B strain is the most commonly reported strain among the children and young adults having age between 0 to 4 years (56% of reported cases) and 5 to 24 years (73 percent of reported cases). On the other side A(HINI)pdm09 viruses are the most commonly reported strain that predominated among age groups between the years 25 to 64 years (53 percent of reported viruses) and 65 years or older than this (60 percent of reported viruses).
At the national level, the outpatient visits due to influenza viruses rose to 6.7% that is much more than the national baseline value of 2.4%. At the regional level, the percentage value rose to10.9% from 4.0%.
The activity of influenza was high in Puerto Rico, New York City, and 45 states and moderate in the US Virgin Islands, Nevada, District of Columbia and New Hampshire. And low in Delaware and Alaska and minimize in Idaho.
During the fourth-week death % due to influenza and pneumonia fell from 7.2% to 7.1%. This percentage is below the percentage (7.2%) of the epidemic threshold for the fourth week.
This season out of a total of 78 deaths,10 pediatric deaths due to influenza were reported for the fifth week. 52 deaths were related to influenza B viruses.26 deaths were seen due to influenza A viruses.
In 2009 during the influenza pandemic, 260 children died between 30 August 2009 and 16 January 2010. During the season at this point, the pediatric death rate was rose to 80 into the 2014-2015 season from 2 two in the 2011-2012 season.
10,314 hospitalized influenza cases were reported confirmed by laboratory tests. Out of these cases, 6416 (62.2%) were related to influenza A virus, 3835 were linked to influenza B virus 32 (0.3%) cases were related to undetermined type of influenza and 31 (0.3%) were linked to co-infection with influenza B and influenza A. Out of influenza A viruses 1397 (92.6%) cases were A(H1N1) pdm09 virus and 112 (7.4%) cases were A (H3N2).
CDC writes in the report that a week ago the hospitalization rate rose from 29.7 to 35.5 per 100,000 population. The rate of hospitalization during this season remains the same as in recent seasons. But these rates were seen high among children and young adults as compared to recent seasons.
The hospitalization rate was highest among individuals aged 65 years and older (85.1 per 100,000), followed by children younger than 5 years (56.9). Among adults aged 18 to 49 years, the hospitalization rate was 20.2 per 100,000.
According to the CDC, vaccination is the best way of protecting against influenza viruses and their complications. Anti-viral medications are recommended for those who have influenza. These medications synergistically control influenza along with the vaccine. Four medications approved by FDA are used in the U.S. for treating almost all (> 90%) the influenza viruses’ cases during this season.