A woman who impos food from Mexico and spends several months per year in rural Mexico had to have a compound leg fracture pinned and set in Mexico and has returned 3 days later. She now has signs of acute appendicitis and is taken to surgery in Houston. When her appendix is removed, it is found to contain a light-colored, 20.5-cm long roundworm and bile-stained knobby eggs consistent with Ascaris. How did she acquire this infection?