if (something) catches a cold, (something else) gets pneumonia

If a person, group, or entity has a problem or experiences a negative situation, a related person, group, or entity will consequently have a worse problem or will experience a more negative situation. If Paris catches a cold, Europe gets pneumonia. Terrorism in France affects security throughout the continent. You need to keep Aunt Mary happy because, if she catches a cold, Mom gets pneumonia, and you know who else will be miserable along with them? Us! If the executive office catches a cold, we all get pneumonia—in the form of tons more work!