U.S. health officials say the flu outbreak this winter is on track to be one of the most severe in the past 15 years.
In their latest weekly report Friday, the Centers for Disease Control and Prevention (CDC) said the flu is now widespread in every U.S. state except for Hawaii. The CDC said at this rate of infection, by the end of the flu season, around 34 million people will have come down with the flu.
Officials say last week, 1 in 15 doctor visits across the country was for symptoms of flu.
Health officials say more people are seeking care for flulike illness than at any other time since the 2009 swine flu pandemic that swept the country. Apart from that outbreak, the last time the country experienced such high levels of seasonal flu was in 2003-04.
The CDC said the virus this winter has caused nearly 12,000 people to be hospitalized and killed 37 children. Officials say the death toll of children is likely to rise as pediatric deaths must first be reported to a medical examiner and can take longer to be documented.
Differences this year
The flu typically affects children and the elderly the most. However, hospitalization rates for people 50 to 64 — those who mostly fall under the baby boomer demographic — has been unusually high this season. Officials say the rate of hospitalization for baby boomers is 44.2 per 100,000 people, which is nearly triple what it was last season.
The CDC does not track adult flu deaths directly.
This year's flu strain, mostly the H3N2 flu virus, is the same main bug from last winter, which did not have as severe an outbreak. Experts say that they are not sure why the pandemic is so bad this year and that flu seasons are notoriously hard to predict.
Dr. Dan Jernigan, director of the influenza division at the CDC, told reporters on a conference call Friday that one notable difference in this year’s flu outbreak is that the pandemic hit almost all states in the country at the same time. “We often see different parts of the country light up at different times, but there is lots of flu all at the same time” this year, he said.
Jernigan said a surge of cases in January could have been caused by children returning to school after the Christmas break and spreading the virus.
The flu season usually peaks in February. Influenza activity has already begun to taper off in some parts of the United States, particularly in California, which has been one of the hardest-hit states. Officials say this flu season also began early and so could end earlier.
Flu is a contagious respiratory illness that causes such symptoms as fever, cough, muscle aches, headaches and fatigue. Most people who get the flu get better within a week or two. However, some people develop serious complications caused by viral infection of the nasal passages and throat and lungs.
The CDC recommends a flu vaccine for everyone older than 6 months. However, officials say this year's vaccine is only about 30 percent effective in preventing infection.