7 month with salmonella

After my daughter has had the diarrhea for the past week, I just found out today that she has salmonella. I have no idea how she got it. She hasn’t even been introduced to the foods yet that mainly cause this. The Dr said that they were sending her stool sample to state and they will more then likely be contacting me and asking me questions about her formula. Has anyone else dealt with their young baby having salmonella? She is going to be on a prescription for 10 days but the Dr said that salmonella can last in her system for up to 3 months. If anyone with experience could share, that would be helpful!