Ascariasis is an infection caused by the roundworm Ascaris lumbricoides. This parasite lives in the intestines of humans and can grow up to 12 inches long. People usually get infected by ingesting eggs found in contaminated food, water, or soil. Symptoms can include abdominal pain, diarrhea, and malnutrition, especially in children. Preventing ascariasis involves good hygiene practices, such as washing hands before eating and ensuring food is properly cooked. In areas where the infection is common, public health measures like improving sanitation and education about parasite prevention can help reduce the spread of this disease.