Ascaris (Roundworm) Antibody Test

Ascaris lumbricoides is the largest intestinal roundworm to infect humans and remains one of the most common parasitic infections worldwide. This blood test detects antibodies produced by the immune system in response to Ascaris exposure, helping clinicians investigate persistent or unexplained symptoms that may point to a parasitic cause.

The test is suited to people with risk factors or symptoms suggestive of ascariasis, including those who have travelled or lived in regions where sanitation is limited, those with close contact with contaminated soil or food, and individuals experiencing recurrent abdominal discomfort, bloating, coughing, or other concerning digestive or respiratory symptoms. It can also support investigation of unexplained eosinophilia, where raised eosinophil counts on a routine blood count raise the possibility of a parasitic infection.

Parasitic Infection
- Ascaris lumbricoides antibodies (Ascaris Ab): detects the immune response to Ascaris roundworm, indicating current or past exposure.

A positive result does not by itself confirm active infection, as antibodies can persist after the parasite has cleared. Your doctor will interpret the result alongside your symptoms, travel and exposure history, and other investigations to decide whether treatment or further testing is needed.

Why it matters
Ascaris infection is treatable, but it is easily overlooked because symptoms can be vague or mistaken for other digestive complaints. Identifying exposure through antibody testing gives you and your doctor a clearer picture, supports timely treatment where appropriate, and helps rule out a parasitic cause when symptoms have been puzzling or persistent.