Ascariasis

Ascariasis 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.

Definition

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 240,000 eggs per day. [1] Diemert DJ. Ascariasis. In: Guerrant RL, Walker DH, Weller PF, eds. Tropical infectious diseases: principles, pathogens and practice. 3rd ed. Edinburgh: W.B. Saunders; 2011:794-8. [2] Pullan RL, Smith JL, Jasrasaria R, et al. Global numbers of infection and disease burden of soil transmitted helminth infections in 2010. Parasit Vectors. 2014 Jan 21;7:37. https://www.doi.org/10.1186/1756-3305-7-37 http://www.ncbi.nlm.nih.gov/pubmed/24447578?tool=bestpractice.com ​ An estimated 730 to 804 million humans are infected worldwide, most of whom are children in developing countries.​ [3] Jourdan PM, Lamberton PHL, Fenwick A, et al. Soil-transmitted helminth infections. Lancet. 2018 Jan 20;391(10117):252-65. http://www.ncbi.nlm.nih.gov/pubmed/28882382?tool=bestpractice.com ​​ [4] Holland C, Sepidarkish M, Deslyper G, et al. Global prevalence of Ascaris infection in humans (2010-2021): a systematic review and meta-analysis. Infect Dis Poverty. 2022 Nov 18;11(1):113. https://www.doi.org/10.1186/s40249-022-01038-z http://www.ncbi.nlm.nih.gov/pubmed/36401308?tool=bestpractice.com ​ Although frequently asymptomatic, ascariasis can cause gastrointestinal and hepatobiliary obstruction, and can contribute to cognitive and growth delay in children. [1] Diemert DJ. Ascariasis. In: Guerrant RL, Walker DH, Weller PF, eds. Tropical infectious diseases: principles, pathogens and practice. 3rd ed. Edinburgh: W.B. Saunders; 2011:794-8. [2] Pullan RL, Smith JL, Jasrasaria R, et al. Global numbers of infection and disease burden of soil transmitted helminth infections in 2010. Parasit Vectors. 2014 Jan 21;7:37. https://www.doi.org/10.1186/1756-3305-7-37 http://www.ncbi.nlm.nih.gov/pubmed/24447578?tool=bestpractice.com

History and exam

Key diagnostic factors