Enterobius vermicularis (Pinworms)

The nematodes live in the human intestine, creeping out through the anus at night to deposit eggs around the anus. Most cases happen in children. People get infected by accidentally swallowing the eggs, the stage infective to humans. The most common symptom is itching in the anal area. Infected children unconsciously scratch around the anus and their hands become contaminated by the eggs. It is important to disinfect anything they touch, including their clothes. Adult people sometimes get infected through contaminated clothes, etc. The worm is easily removed by chemotherapy, but re-infection may occur.