Human Roundworm

Human Roundworm

Ascaris lumbricoides, the large human roundworm, is the most massive nematode to parasitize humans, growing up to 16 inches (40 centimeters) long and often as thick as a pencil. Infections of this intestinal roundworm, called ascariasis, are extremely common in rural communities around the world and affect as many as 1.5 billion people, almost one-quarter of the world's population.