When you catch a cold, it is most likely you contracted it from
a pathogen
rickettsia
fleas
mites

The answer is: a pathogen

A pathogen is anything that can cause a disease, such as a virus or bacteria.

'Path' is like pathology and 'gen' is like generation/ creation.

When you catch a cold, it's typically a viral infection such as rhinovirus, so pathogen works.

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