Infectious diseases are caused by pathogens like bacteria, viruses, fungi and protists. Some harmful bacteria cause diseases such as tetanus, salmonellosis, conjunctivitis, pneumonia and tonsillitis. Viruses also cause diseases in humans, including measles, chickenpox, the flu, mumps, common colds, papilloma and AIDS. Infectious diseases are caused by microorganisms that can spread from person to person.

1. DISEASES AND ILLNESSES
Celia lópez marínez
Unit 3 : Health and illness.

2. INFECTIOUS DISEASES
 Ifectious diseases: are caused by harmful organisms called
pathogens are bacteria and viruses. Other microorganisms ,
such assome kinds of fungi and protists , can also cause
diases.
 Some harmful bacteria cause diseases such as tetanus ,
salmonellosis, conjunctivitis and some type of pneumonia
and tonsilitis.
 Some viruses causes diases in humans, such as measles
chickenpox , the flu , mumps, common colds , papilloma and
AIDS.