Ascariasis. An infection to watch for in immigrants.

Infection with Ascaris lumbricoides, a roundworm that invades the human digestive tract, affects about 25% of the world's population. Manifestations of ascariasis vary and include constitutional symptoms, particularly pulmonary and gastrointestinal complaints. Complications include pneumonitis, intestinal obstruction, and damage to vital organs. Diagnosis is made in most cases by sampling stool for ova and parasites. Treatment with an anthelmintic agent is usually effective in mild cases, and prognosis is excellent. More severe infection may cause significant morbidity and require surgical intervention.