Kotowaza of the day: Common cold, or gateway illness?

Japanese:

風邪は万病の基*

Romanized:

Kaze-wa manbyou-no moto

Meaning of Japanese:

A cold may lead to thousands of different illnesses

English equivalent:

A May cold is a 30-day cold

*Also written 風邪は万病の元, 風邪は百病の本, or other variations.