Introduction
Ascariasis is caused by Ascaris lumbricoides, the most common intestinal helminth and the largest intestinal nematode
-it can reach up to 40 cm in length
-it is particularly common in the Far East, India, and South Africa
-it is seen following ingestion of foods or vegetables fertilized by ‘night soil’ (human feces) or playing in the infected soil
Life cycle: Humans ingest eggs, which form larvae in the gut, where after hatching, they migrate through the blood to the lungs, where they enter the alveoli,ascend the bronchial tree, and are swallowed. In the gut, they become adults and lay eggs that are passed in the feces. Adult worms can migrate to the appendix, bile duct or pancreatic duct, causing obstruction and inflammation
Symptoms & Signs
Most persons with Ascaris infection are asymptomatic
Lungs: migrating worms can cause fever, cough, chest pain, dyspnea, eosinophilia, or “Löffler syndrome”
Gastrointestinal: Abdominal pain, obstruction, volvulus, perforation, appendicitis
Biliary: Cholangitis, cholecystitis, obstructive jaundice, pancreatitis
Diagnosis
Adult worms: can be seen emerging from the mouth, nose, or anus or in stools
Chest X ray: migratory pulmonary infiltrates
ERCP: linear filling defects within the bile ducts
Eggs in stool: egg is oval with an irregular surface with a typical “scalloped” edge
Treatment
Effective agents: Albendazole, mebendazole, ivermectin, or pyrantel pamoate