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A 48-year-old member asked:

Is it true that all contagious diseases are not infectious but all infectious diseases are contagious?

3 doctor answers6 doctors weighed in
Dr. Jay Park
Dr. Jay Parkanswered
Pediatrics 51 years experience
The other way around: All infectious diseases are not contagious. By definition, "contagious" means being communicable by contact. For instance, rabies is not transmitted by usual contact with infected patient.
Dr. Michael Ein
Infectious Disease 49 years experience
No: You have it completely backwards. Almost if not all contagious diseases are caused by infectious microorganisms. Many infectious diseases such as e. Coli urinary tract infections are not contagious
Dr. Stephen Scholand
Infectious Disease 24 years experience
Contagious disease: By definition - contagious means you're liable to 'catch' something from someone else. I think of 'the flu', chickenpox, 'meningitis' as good examples of that. (So always good to practice hygiene!). Whereas infectious diseases encompasses all that PLUS other diseases caused by 'germs' that may not necessarily be contagious: for example those deadly amoeba that kill kids every summer, Lyme dz etc.

Similar questions

A 36-year-old member asked:

What is the difference between a communicable disease and a contagious disease and an infectious disease?

2 doctor answers4 doctors weighed in
Dr. Sheila Calderon
Internal Medicine 42 years experience
Spread: A communicable disease is a disease many others may get and that is why we have vaccinations. A contagious disease is a disease someone in contact with the person may catch. An infectious disease is a disease that may be spread within the person such as a virus or a bacterial or a fungal infection. An infectious disease may be contagious and communicable but does not have to be.

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Last updated Jan 21, 2016
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