Cambridge O Level Biology · Syllabus 5090 · Disease and Immunity
Transmissible Disease
What is Transmissible Disease?
A disease in which the pathogen can be passed from one host to another. The definition depends on whether the pathogen can move between hosts, not on how severe the illness is, so many serious diseases are not transmissible and some mild ones are.
This definition is part of the Disease and Immunity chapter in Cambridge O Level Biology.
Transmissible Disease in context
A pathogen is a disease-causing organism, and a transmissible disease is one in which the pathogen can pass from one host to another. Every method of disease control in this chapter works by breaking one specific link in the chain that runs from an infected host, along a route of transmission, past the body's barriers, into a new host. Vaccination is the one control that acts on the far end of the chain: it prepares the immune system before the pathogen ever arrives.
Common mistakes with Transmissible Disease
- "Every disease is transmissible." Transmissible means a pathogen can pass from one host to another. Diseases caused by diet, by inherited alleles or by the body's own processes have no pathogen to pass. Write A transmissible disease is one in which the pathogen can be passed from one host to another; many diseases are not transmissible.