A bad flu season was forecast Thursday by the Centers for Disease Control and Prevention, blamed mainly on this year’s vaccine not being a good match for the virus hitting hardest across the U.S.
Still, local and federal health officials are urging people to get a flu shot as soon as possible.
“Most of the other [flu] viruses identified are the same as the viruses covered by the vaccine,” said Dr. Tom Frieden, the CDC’s director.
During a national media briefing, Frieden explained that the H3N2 flu strain appears to be causing more flu cases this year than any other strain. It was first seen in 2011 among people who had close contact with infected pigs.
However, the H3N2 strain has mutated enough in recent years that it’s not covered well by the flu vaccine manufactured for this flu season.
When such flu strains circulate, “we tend to have seasons that are the worst flu years, with more hospitalizations from flu and more deaths,” Frieden said. “Unfortunately, about half of the H3N2 viruses that we’ve analyzed this season are different from the H3N2 virus that’s included in this year’s flu vaccine.”
So far this year, Dallas County has confirmed 507 flu cases, of which 85 percent were a type A strain that includes both H3N2 strains. Earlier this week, the first flu-related death was reported in the county, an unidentified adult.
“The H3N2 virus tends to be more severe on young and elderly people and those with underlying health issues,” said Dr. Christopher Perkins, medical director of Dallas County Health and Human Services.
Influenza activity is increasing in Dallas County, with 18.9 percent of tests returning positive for the week ending Nov. 22. Nationally, 9.3 percent of specimens reported to the CDC were positive for influenza during that week.
Daily numbers of emergency department visits for influenza-like illness and numbers of new influenza-associated hospitalizations are increasing in Dallas County, although the outbreak is starting slowly.
Officials are urging people who develop flu symptoms — fever, chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches and fatigue — to see their doctors and be tested. Anyone testing positive for the flu should get a prescription for antiviral medication.
In the United States, all circulating influenza viruses have been susceptible to neuraminidase inhibitor antiviral medications oseltamivir and zanamivir. However, rare sporadic instances of oseltamivir-resistant 2009 H1N1 and H3N2 viruses have been detected worldwide.
Perkins said the flu vaccine is still widely available from doctors, pharmacies and many grocery stores. The health department’s shot clinics also are well stocked.
Adult vaccine is available in the county’s adult immunization clinic on the first floor of the main health department building at 2377 N. Stemmons Freeway in Dallas. Children’s vaccine is available at all county immunization clinics.
Clinic hours are from 8 a.m. to 4 p.m. Monday through Friday. Appointments are not necessary. For more information, call 214-819-2162.