Pediatricians at a Dallas hospital say they have also noticed this year's early start to the flu season.
Doctors at Children's Medical Center said they have noticed a dramatic rise in flu cases since November. The hospital had seven positive cases the week of Nov. 10, 23 cases the week of Nov. 17 and 32 cases the week of Nov. 24. But the hospital had 96 cases in the first week of December.
"This is definitely much earlier than we typically see," said Dr. Tess Barton, who specializes in pediatric infectious diseases. "Our flu season tends to begin and peak in January timeframe."
Barton said it is not clear what is causing the uptick.
"We don't know yet why flu is coming early -- if it’s something about the strain or immunity," she said.
Virginia Ramirez said she made sure her kindergartner was vaccinated as early as she could.
"If they go to school sick, then they get other children sick," she said. "At least she has her shots; she won’t get sick as much."
Last week, another Dallas pediatrician also reported seeing a spike in cases. Dallas County last week also reported a dramatic spike in the number of flu cases in November, and Tarrant County said it was already seeing widespread influenza activity.
Children's Medical Center doctors say this is the earliest start of the flu season in 10 years.
"Parents should always be concerned about the flu," Barton said. "The flu can really range from a reasonably mild fever illness like a cold to very severe illnesses, and every year there are deaths related to influenza in children."
Barton said many, but not all, of the strains now circulating are covered by available vaccines.