It's very hard to tell people, when there's an epidemic spreading that threatens, particularly, their parents or elderly people that they know, that they should go about things knowing that their activity is spreading this disease.

很难告诉人们，当流行病蔓延威胁到他们的父母或他们认识的老人时，他们应该知道他们的活动正在传播这种疾病。