It’s been a mild flu season in North Carolina, but experts aren’t sure it will stay that way.
This week’s flu report from the state Department of Health and Human Services showed that far fewer patients have flu-like symptoms than at this time last year. The state has seen two flu-related deaths so far this season compared with 163 at this point last year.
So is it a light year for the flu? Or is the worst yet to come?
“People postulate about all these things,” said Dr. Cameron Wolfe, an infectious disease specialist at Duke Medicine. “But they are very much postulating.”
Nationally, the flu often peaks in February, according to the federal Centers for Disease Control and Prevention. Unlike North Carolina, the nation saw a slight increase in flu activity in the week ending Jan. 30.
Wolfe said the flu’s peak is usually delayed in Northern states. In North Carolina, the flu has peaked in late December or early January for the past three years.
“We got a little bit of an uptick around December, when we usually do,” said Wolfe, leading him to believe that the state won’t see a surge of flu virus in February.
The DHHS report showed a slight decrease in patients with influenza-like illnesses across the state in the week ending Jan. 30. WakeMed Hospital in Cary saw just one confirmed flu case last week.
But David Weber, an infectious disease expert and professor at UNC School of Medicine, said he expects flu cases to increase in coming weeks – but cautions that he’s just guessing. UNC Medical Center saw a boost in flu patients last week even as patients with other respiratory viruses decreased.
“Flu season can peak as early as November or as late as May,” said Weber. “Nobody really knows.”
Experts also don’t know exactly why the season has been mild so far.
“People often want to say it was a warmer winter or drier winter or wetter winter,” said Dr. Zack Moore, an epidemiologist with the N.C. Department of Health and Human Services. “But we don’t understand all the factors well enough to say that.”
Moore said there is a correlation between a mild flu season and having a mix of flu strains. “When we have a bad year, there is usually one strain that really takes off,” said Moore.
As for the warm weather, Weber said experts are aware that countries near the equator, which enjoy warm weather year round, have no sharp spike in the flu at all.
An especially effective flu vaccine may also be contributing to the less intense flu season. Last year, the U.S. Centers for Disease Control and Prevention said a mutation in the most prevalent flu strain made the vaccine less effective, contributing to a national flu epidemic.
“This year the viruses circulating are very similar if not identical to the strains in the vaccine,” Weber said.
The CDC recommends an annual vaccine for everyone older than 6 months. Infants, pediatric patients and elderly adults are most likely to experience severe flu-like symptoms.
Moore said although it is better to get the vaccine early, it is still not too late.
“The flu is still out there, and that is our best defense against it,” he said.