Compléter Nat.Sc.5-Unit 04-Act.03Version en ligne WE KEEP HEALTHY par JOAQUIN MUNIOSGUREN PRIETO 1 body infectious contaminated pathogens water signs symptoms symptoms Germs skin disease breathe convalescence are tiny living things and viruses that can cause in humans . They are also known as . They enter the through cuts in the , through the nose and mouth when we , and through food and drinking . A person who is ill notices like aches , pains , and tiredness . A medical professional looks for such as fever , or a rash on the skin . The stages of disease include the infection , the and the .