It’s been a quiet flu season in North Carolina so far, but a report released by the state Department of Health and Human Services on Thursday suggests that may be changing.
The weekly flu report says there have been no documented deaths from influenza in the state as of Dec. 26. At this time a year ago, 26 people had already died from the flu, and the Centers for Disease Control and Prevention had declared a national flu epidemic.
But the number of flu-like illnesses reported by a network of health care providers in the state has begun to tick up. While still far short of last year’s season, which peaked right around New Year’s Day, the trend mirrors the 2013-2014 season in which 107 people died of flu in North Carolina.
The flu never fails to arrive, doctors warn, even when it’s behind schedule.
“It’s remarkably lower than other years,” Cameron Wolfe, an infectious disease specialist at Duke University Hospital, said about the illness so far this year. “Now that being said, it would be foolish to assume that won’t happen in January, February.”
Local hospital emergency rooms had barely seen a trace of flu patients earlier this week: A single case documented at UNC Hospitals in Chapel Hill, a pair of cases at UNC Rex Hospital in Raleigh, and two at WakeMed hospital in Raleigh.
“Not only no flu deaths, but no flu,” said David Weber, medical director for epidemiology at UNC Hospitals and a professor of infectious diseases at UNC-Chapel Hill. “This year is a late peak year.”
For the past three years, North Carolina’s annual flu outbreak peaked in January and February, which is generally considered late for the state. In prior years, the flu had done its greatest damage earlier, during the final weeks of the year. The reasons for the timing – and intensity – of each year’s flu season is more or less a mystery.
Still, the flu’s near-absence so far and the possible causes have not passed without commentary.
“Part of it may be the warm weather,” Weber said. “Part of it may be that we have had a very good match year between the vaccine and the flu (strain).
“And part of it is just – who knows?” he said.
Duke’s Wolfe blamed the flu’s hibernation on the springlike weather, among other factors.
“People don’t huddle and congregate nearly as much, so we don’t find influenza spreads as efficiently between people,” Wolfe said by email. “Also we’ve generally done a better job at getting folk vaccinated early.”
Vaccinations reduce the risk of flu illness by at least 50 percent among the general population, according to the CDC.
There are indications that the virus may be getting ready to make a belated appearance. A key early indicator of a flu outbreak is patients complaining to doctors of flu-like symptoms, and that measure has moved upward in the past two weeks, according to data collected from doctors and hospitals through the Outpatient Influenza-like Illness Surveillance Network compiled by the Centers for Disease Control and Prevention.
“We expect that it will continue to increase,” said Zack Moore, an epidemiologist in the state’s Division of Public Health. “We all know all three types of viruses are out there and are circulating.”
The impact of influenza can vary widely from year to year. Last season, flu claimed 218 lives in North Carolina, the most since authorities began tracking adult and pediatric flu death rates in 2009. Two years earlier, the flu season resulted in just nine deaths, Moore said.
Meanwhile, N.C. Children’s Hospital on Monday restricted visits from children ages 11 and younger. The cause: a spike in unrelated respiratory viruses, such as the rhinovirus, parainfluenza and RSV.
Weber said that in December, UNC Hospitals emergency doctors have seen a doubling of patients infected with these viruses, whose symptoms are nearly identical to influenza.
WakeMed Health and Hospitals has had similar visitation restrictions in place for several weeks. The system imposes them every year.