Minnesota health officials say teens are fueling a slight uptick in COVID-19 activity. A report released yesterday showed an increase in the state positivity rate of diagnostic testing to three-point-nine-percent. The Minnesota Department of Health has reported close to seven-thousand more diagnosed cases of COVID-19 in a seven-day period that ended yesterday, and ten percent involved teens 15 to 19 years old.   Officials say the risk of transmission increased earlier this year with the return to in-person classes and youth sports activities.