(St. Paul, MN)  --  State health officials are concerned about a rise in new COVID-19 infections.  Kris Ehresmann with the Minnesota Department of Health says the Delta variant is responsible for about 75-percent of the new cases.  Ehresmann said, "our concern is for some of these regions of the state where there is lower vaccination...that will be kind of the fuel for a potential fire with increased spread and caused by the variants."  Minnesota's hospitals were caring for 109 COVID-19 patients on Monday.  That's the highest number since June 23rd.  Over the past week, an average of 99 people have been treated for COVID-19 complications each day.  Ehresmann says vaccination rates are the lowest in Greater Minnesota.