LITTLE ROCK-Arkansas received 15 more reports of flu fatalities in the past week, raising the death toll to 140 in what's already become the state's deadliest flu season in at least 17 years.
The 15 deaths were reported to the Health Department in a seven-day span ending Tuesday. Of those deaths, 10 were 65 years or older, the Arkansas Democrat-Gazette reported.
The rate of transmission remains high based on information from hospitals and doctor offices, said state epidemiologist Dirk Haselow. He said that influenza B surpassed influenza A last week for the first time this season. Influenza B is more common in children than in adults.
"In my history at the Health Department, I've never seen a season dominated by influenza B, or that switched from one strain to another," said Haselow, who started at the department in 2002.
Until last week, the dominant flu virus in Arkansas was H3N2, a type A virus that usually causes more illness than other viruses and mutates faster, making vaccines less effective against it. Type B viruses tend to hit children harder because they are less likely to have been exposed to them in past seasons, said Jose Romero, chief of infectious disease at Arkansas Children's Hospital.
The U.S. Centers for Disease Control and Prevention reported last week that the number of infected patients visiting doctors across the country has reached the level of the 2009 swine flu epidemic, when a new strain of H1N1, an influenza A virus, spread nationwide.
The CDC said the flu vaccine is usually more effective against type B viruses and H1N1 than it is against H3N2. County health offices offer the vaccine at no charge to those who are uninsured.
"Even if you've had the flu, it's not too late to get your shot," Haselow said.