Ascariasis overview


 * Associate Editor-In-Chief: Imtiaz Ahmed Wani, M.B.B.S

Overview
Ascariasis is a human disease caused by the parasitic roundworm Ascaris lumbricoides. Perhaps as many as one quarter of the world's people are infected, and ascariasis is particularly prevalent in tropical regions and in areas of poor hygiene. Other species of the genus Ascarisare parasitic and can cause disease in domestic animals.

Infection occurs through ingestion of food contaminated with feces containing Ascaris eggs. The larvae hatch, burrow through the intestine, reach the lungs, and finally migrate up the respiratory tract. From there they are then reswallowed and mature in the intestine, growing up to 30 cm (12 in.) in length and anchoring themselves to the intestinal wall.

Infections are usually asymptomatic, especially if the number of worms is small. They may however be accompanied byinflammation, fever, and diarrhea, and serious problems may develop if the worms migrate to other parts of the body.

Most people have no symptoms that are noticeable, but infection may cause slower growth and slower weight gain. If heavily infected, patients may have abdominal pain. Sometimes, while the immature worms migrate through the lungs, patients may cough and have difficulty breathing. Due to very heavy worm infection, intestines may become blocked.