Does infection spread through the bloodstream, such as a bacterial infection on ankle can spread to an ear infection?

Bacteremia: Infections can spread through the blood stream - when you hear the word "Sepsis" that implies a bacteria is in the blood stream and causing havoc on the body. Could an infection that started in the ankle get into the blood stream? Sure. Once it's in the blood stream could it seed other sites? Sure. If you didn't have high fever and signs of blood infection then I doubt your ear infection is relate

Separate issue: Infections tend to be compartmentalized or localized to a source of germ entry.An ankle issue might be from a scrape or bug bite. The ear infection got there from the throat. You can get germs in the blood, but that makes you sick enough to kill you pretty quick. The germ doesn't sneak up to your ear from your ankle.