"That's a signal of how very intense this flu season has been". Schuchat noted that overall hospitalizations are now significantly higher than what has been seen for this time of year since CDC's current tracking system began almost a decade ago in 2010, and "the rate is approaching the final rate of hospitalizations that we observed at the end of the active 2014-2015 flu season".
Although deaths among children - at 63 kids - and adults have not been extremely high, it is possible they could increase in line with hospitalization rates, she said. The Centers for Disease Control and Prevention Friday reported 42 states had heavy flu-related patient traffic last week, up from 39 the week before.
The dominant flu strain this season, influenza A (H3N2), is especially potent, linked with severe disease and death, particularly among children and the elderly.
Flu-related hospitalizations rose to about 60 people out of every 100,000 in the fifth week of 2018, the CDC said Friday in its weekly surveillance report.
"The previously recorded high for that was 7.6 percent for a non-pandemic year in 2003-2004", Schuchat said.
"This season is a wake-up call about how severe influenza can be and how we can never let our guard down", she said. They say they haven't seen numbers this high since 2009, the year of the swine flu pandemic.
"We found the smart thermometer data are highly correlated with information obtained from traditional public health surveillance systems and can be used to improve forecasting of influenza-like illness activity, possibly giving warnings of changes in disease activity weeks in advance", Aaron Miller, a postdoctoral scholar at University of Iowa in the U.S., was quoted as saying in global media outlets. The CDC does not require national reporting of flu deaths in adults. The CDC uses this data to determine the timing and intensity of flu activity. "In recent weeks, the percent of specimens testing positive for influenza A has been decreasing, while the percent positive for influenza B viruses has continued to increase".
The prevalent flu strain is still the Influenza A or the H2N2 but the CDC also noted rising strains of Influenza B and H1NI virus.
There are four types of influenza viruses: A, B, C and D. Human influenza A and B viruses cause seasonal epidemics of disease nearly every winter in the United States. Of the 978 influenza A viruses that were subtyped, 834 (85.3%) were H3N2 viruses and 144 (14.7%) were (H1N1) pdm09 viruses.
The proportion of deaths attributed to pneumonia and influenza (P&I) is high again at 10.1% for the week ending January 20, 2018 (week 3). It's the fourth week that the system has been above the epidemic threshold this flu season. The most frequently identified influenza virus subtype reported by public health laboratories was influenza A (H3N2) virus. "Flu is incredibly hard to predict, and we don't know if we've hit a peak".