To develop a pcr test, for a never before seen virus what do researches first sequence CAN SOMEONE REALLY HELP ME !

Adisease that is characteristic of a particular local region is called:

Lina went camping in the woods. while camping, she accidentally touched a strange plant. her hand immediately started itching, and her skin erupted in hives. after she got home, her grandmother cooked some oatmeal, wrapped it in a cloth, and put it on lina’s affected hand. lina’s grandmother followed a traditional remedy.

Why is the first step in responding to life-threading situations to assess the situation?