Fill in the Blanks INFECTIOUS DISEASES.Online version Completa este texto con las palabras que faltan sobre INFECTIOUS DISEASES. Tenéis que hacerlo en el orden que aparecen las palabras en el libro. by Elena Tomás 1 contagious nose viruses protists mouth fungi air pathogens transmitted bacteria Infectious diseases are caused by harmful organisms called entering our body . The most common pathogens are and . Other microorganisms , such as some kinds of and , can also cause diseases . An infectious disease is considered if it is easily from one person to another . Some diseases , such as colds , spread from person to person through the . The pathogens usually enter the body through the or .