<P> Infectious diseases are sometimes called contagious disease when they are easily transmitted by contact with an ill person or their secretions ( e.g. , influenza ) . Thus , a contagious disease is a subset of infectious disease that is especially infective or easily transmitted . Other types of infectious / transmissible / communicable diseases with more specialized routes of infection , such as vector transmission or sexual transmission , are usually not regarded as `` contagious '' , and often do not require medical isolation ( sometimes loosely called quarantine ) of victims . However , this specialized connotation of the word `` contagious '' and `` contagious disease '' ( easy transmissibility ) is not always respected in popular use . Infectious diseases are commonly transmitted from person to person through direct contact . The types of contact are through person to person and droplet spread . Indirect contact such as airborne transmission , contaminated objects , food and drinking water , animal person contact , animal reservoirs , insect bites , and environmental reservoirs are another way infectious diseases are transmitted , </P>
<P> Infectious diseases are sometimes called contagious disease when they are easily transmitted by contact with an ill person or their secretions ( e.g. , influenza ) . Thus , a contagious disease is a subset of infectious disease that is especially infective or easily transmitted . Other types of infectious / transmissible / communicable diseases with more specialized routes of infection , such as vector transmission or sexual transmission , are usually not regarded as `` contagious '' , and often do not require medical isolation ( sometimes loosely called quarantine ) of victims . However , this specialized connotation of the word `` contagious '' and `` contagious disease '' ( easy transmissibility ) is not always respected in popular use . Infectious diseases are commonly transmitted from person to person through direct contact . The types of contact are through person to person and droplet spread . Indirect contact such as airborne transmission , contaminated objects , food and drinking water , animal person contact , animal reservoirs , insect bites , and environmental reservoirs are another way infectious diseases are transmitted , </P>
the person to whom the infectious agent is passed is
the person to whom the infectious agent is passed is
contagious
contagious