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Infectious Diseases

Also called: Communicable diseases 
 
 

Infectious diseases kill more people worldwide than any other single cause. Infectious diseases are caused by germs. Germs are tiny living things that are found everywhere - in air, soil and water. You can get infected by touching, eating, drinking or breathing something that contains a germ. Germs can also spread through animal and insect bites, kissing and sexual contact. Vaccines, proper hand washing and medicines can help prevent infections.

There are four main kinds of germs:

  • Bacteria - one-celled germs that multiply quickly and may release chemicals which can make you sick
  • Viruses - capsules that contain genetic material, and use your own cells to multiply
  • Fungi - primitive plants, like mushrooms or mildew
  • Protozoa - one-celled animals that use other living things for food and a place to live

NIH: National Institute of Allergy and Infectious Diseases

 

 

 
 
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MEDICAL ENCYCLOPEDIA  

National Institutes of Health

 

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MedlinePlus links to health information from the National Institutes of Health and other federal government agencies. MedlinePlus also links to health information from non-government Web sites. See our disclaimer about external links and our quality guidelines.