Can you get hiv or hep c from sharing a toothbrush?

Theoretically, yes.: Toothbrushes come in contact with minute amounts of blood in saliva. Sharing personal care articles, therefore, it is not advisable.

Not likely: It can possibly happen if the person has a high viral load in the blood and have gums bleed all over the tooth brush and you use it immediately after they do. If you think that you may have been exposed then get tested.