Infection is concentrated in developing countries of Asia, Africa, and Latin America.
Acquired by ingesting eggs that are passed in human faeces and mature in the soil.
Diagnosis can be made in most cases by finding characteristic eggs in a stool sample.
Treated with oral anthelmintic agents.
Ascaris lumbricoides, a fleshy, cylindrical roundworm, is the largest nematode to colonise the human gut. Adult male and female worms live for about a year, during which time a single female can produce up to 200,000 eggs per day. An estimated 800 to 1200 million humans are infected worldwide, most of whom are children in developing countries. Although frequently asymptomatic, ascariasis can cause gastrointestinal and hepatobiliary obstruction, and can contribute to cognitive and growth delay in children.
History and exam
- co-infection with other parasites
- developmental delay
- rhonchi, rales
- urticarial skin lesions
- abdominal pain
- abdominal distension
- reduced or absent bowel sounds
- RUQ tenderness
- signs/symptoms of iron deficiency anaemia or kwashiorkor
Professor of Pediatrics, Microbial Pathogenesis, and Public Health
Yale World Fellows Program
MC declares that he has no competing interests.
Dr Michael Cappello would like to gratefully acknowledge Dr Samantha H. Johnston and Dr Claire Panosian, previous contributors to this topic. SHJ owns a share in a company (Merck & Co., Inc.) that produces ivermectin, an alternative therapy for ascariasis. CP declares that she has no competing interests.
Stanford Health Promotion Network
Stanford School of Medicine
YM declares that he has no competing interests.
Department of Medical Parasitology and Mycology
School of Public Health
Tehran University of Medical Sciences
MBR declares that he has no competing interests.
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