when A sneezes, B catches a cold

when A ˈsneezes, B catches a ˈcold

(also if A catches a ˈcold, B gets pneuˈmonia less frequent) if one person, organization, country, etc. has a problem, the effects of this on another person, organization or country are much more serious: When Wall Street sneezes, the world catches a cold.
See also: catch, cold