Hello there.  I can understand your concern.  Yes typhoid can re occur. It is possible. Typhoid spreads by faeco-oral route that means water of food contamination. You have to take proper measures to cook the food well, cover the food properly, drink clean and filtered water. House flies are big carriers of these sort of infections. Once infection is detected, take the whole course of antibiotics suggested.  Drink plenty of fluids. Best regards. Dr. Anil kumar jain. Bangalore.