infections
Ascariasis
Introduction
Ascariasis is infection caused byAscaris lumbricoides, an intestinal roundworm, or occasionally byAscaris suum(which causes ascariasis in pigs). People acquire the infection by swallowing the roundworm eggs, usually in food. When first infected, people may have no symptoms or may develop fever, coughing, wheezing, abdominal cramps, nausea, and vomiting. Children with a heavy, chronic infection may not grow normally, or worms can block the intestine or bile duct, resulting in severe pain and vomiting. Doctors usually diagnose the infection by identifying the eggs or worms in a stool sample. People are treated with antiparasitic drugs such asalbendazole. (See also Overview of Parasitic Infections .) Ascariasis is the most common roundworm infection in people, occurring in about 500 million people worldwide, and ascariasis contributes to malnutrition in areas with poor sanitation. About 2,000 to10,000 people die each year from ascariasis. Most deaths occur in children as a result of worms blocking the intestine or bile ducts (tubes that connect the liver and gallbladder to the small intestine). The infection is common in tropical or subtropical areas with poor sanitation. In the United States, ascariasis occurs most often in refugees, immigrants, and people who have traveled to or lived in areas where sanitation is poor. About 500 million people worldwide have a roundworm infection called ascariasis. 