Whose more susceptible to getting upper respiratory tract infections?

Children and family: Children in daycare, and starting in new school often spread respiratory germs (bacteria and viruses) to each other, and then bring the germs home to their families.

Contact route, Body: It depends on two major categories: 1. How you get it: direct contact, respiratory contacts and how close you are to source i.E school, family member. 2. How strong you are: age is a major factor, neonates, infants and elderly are at the highest risk, also immunosuppressed patients can be the most susceptible ones. Why more in cold weather? People more indoor, schools are open, low humidity.