Classifying Infectious Diseases Communicable disease A disease that is easily spread from one host to another. ·Contagious disease A disease that is easily spread from one host to another. Noncommunicable disease A disease that is not transmitted from one host to another.Classifying Infectious Diseases • Communicable disease A disease that is easily spread from one host to another. • Contagious disease A disease that is easily spread from one host to another. • Noncommunicable disease A disease that is not transmitted from one host to another