Health

3. spread from one person or organism to another by direct or indirect contact
5. a disorder of structure or function in a human, animal, or plant
6. any of a group of spore-producing organisms feeding on organic matter
8. conditions or practices conducive to maintaining health and preventing disease
9. an organism, typically a biting insect or tick, that transmits a pathogen, disease, or parasite
10. lung inflammation caused by a bacterial or viral infection
13. an organism causing disease to its host
14. a phylum or group of phyla that comprises the single-celled microscopic animals
15. part of the body's defense to injury or infection

1. a substance used to stimulate immunity to a particular infectious disease or pathogen
2. the period between exposure to an infection and the appearance of the first symptoms
4. an infective agent that typically consists of a nucleic acid molecule in a protein coat
7. a microorganism, especially one which causes disease
11. a member of a large group of unicellular microorganisms
12. the process of infecting or the state of being infected