Ascariasis: challenges in the diagnosis of single worm disease.

One of the most common parasitic infections in humans is ascariasis. While most infectionsare asymptomatic, mild to moderate symptoms may occur due to migration of adult worms. The frequency of single worm infection seems to be increasing. Ascaris eggs are not found in the faeces of most cases infected with a single worm because it is an immature male or female. Diagnosis of such single worm infection is challenging.