Jan. 17 (UPI) -- Despite a significant uptick in flu cases during the first week of the New Year, it seems the United States is not on the verge of a pandemic after all.
According to the latest FluView report from the Centers for Disease Control and Prevention, 4.7 percent of all visits to healthcare professionals during the week ending January 11th were linked with flu-like symptoms -- down from 5.7 percent the previous week.
In all, 6 percent of deaths across the country during the most recent surveillance period were attributable to pneumonia and influenza, far below the agency's pandemic threshold of 6.9 percent.
Still, the CDC estimates that at least 13 million Americans have been sickened by the virus so far this flu season -- with 3 million during the most recent seven day period reported alone. To date, the flu has caused more than 120,000 to be hospitalized across the country.
In all, more than 6,600 have died from the virus, including 39 children.
Based on lab testing, approximately two-thirds of confirmed cases of influenza nationally are type B, the less virulent -- and contagious -- form.
During the week ending January 11, "high" flu activity was reported by New York City, Puerto Rico and 32 states -- Alabama, Arkansas, California, Colorado, Connecticut, Georgia, Illinois, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Mississippi, Nebraska, New Jersey, New Mexico, New York, North Carolina, North Dakota, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, Wisconsin and Wyoming.
The relatively mild flu season in 2019-20, at least to date, is likely down to the relative effectiveness of the vaccines currently in use. The vaccines available for this winter cover at least two of the virus strains reported to be in circulation, which experts told UPI appear to be having some positive effect.
Vaccines are developed based on virus surveillance data and projections by epidemiologists. Earlier this week, research published in the journal The Lancet Digital Health found that data from "wearable devices" -- like Fitbit-- may be able to assist in influenza surveillance. The authors noted that resting heart rate tends to spike during infectious episodes, a trend that may be spotted by smartwatches and other fitness trackers, that track heart rate.
Using data from 47,249 Fitbit users over a 60-day period, they were able to spot elevated resting heart rate and changes to routine sleep patterns, which may be indicators that they had fallen ill.
The data was compared to weekly estimates for influenza-like illness rates reported by the CDC, and the "closest alignment" was found when abnormal resting heart rate was defined as half a standard deviation above normal and sleep more than half a standard deviation below.
"Responding more quickly to influenza outbreaks can prevent further spread and infection, and we were curious to see if sensor data could improve real-time surveillance at the state level," study co-author Jennifer Radin, Scripps Research Translational Institute, said in a press release. "We demonstrate the potential for metrics from wearable devices to enhance flu surveillance and consequently improve public health responses. In the future as these devices improve, and with access to 24/7 real-time data, it may be possible to identify rates of influenza on a daily instead of weekly basis."