Cases are rising rapidly in 47 US states during this period. A new wave is gaining speed nationwide. Data shows infection numbers climbing across the country. Health officials are tracking the fast spread with concern. Reports say this is happening before the usual flu season starting. Hot spots are concentrated in the central and southern regions. Experts point to more travel and less masking as reasons for the rise. Flu activity remains low for now. Hospitalizations have not climbed yet. People are being told to remain careful as the trend continues.