LACROSSE, Wis. — LaCrosse is seeing coronavirus infection in more people in their 20s.  County health director Jen Rombalski said that of the 15 new cases, seven were in the 20-29 age group — four men and three women. There also has been a teen-age girl, Rombalski said. The incidence of younger people runs contrary to an earlier notion that younger people have less vulnerable to the virus.