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Ascariasis Workup

  • Author: David R Haburchak, MD, FACP; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
Updated: Apr 15, 2016

Laboratory Studies

Stool examination for ova and parasites almost always discloses large, brown 60 µm X 50 µm trilayered eggs in persons with ascariasis. However, stool examination may be negative for ova for up to 40 days after infection because of the time needed for migration and maturation of the worm. The outer surfaces of fertilized eggs have an uneven mucopolysaccharide coat.

Ascaris larvae may be observed in microscopic wet preparations of sputum during the pulmonary migration phase.

CBC counts show eosinophilia during the tissue migration phase of the infection.

Serological tests are not clinically useful for ascariasis.


Imaging Studies

Chest radiographs may show fleeting opacities during pulmonary migration.

Abdominal radiographs may show a whirlpool pattern of intraluminal worms. Narrow-based air fluid levels without distended loops of bowel on upright plain films suggest partial obstruction. Wide-based air fluid levels with distended loops suggest complete obstruction.

Worms have been increasingly identified in the biliary duct or gallbladder with ultrasonography and CT scanning.[21] Liver granulomata due to A suum infection have been described as ill-defined, 3- to 35-mm, nodular- or wedge-shaped lesions in the periportal or subcapsular regions.


Other Tests

Endoscopic retrograde cholangiopancreatography (ERCP) has become a commonly used procedure for both diagnosis of ascariasis and removal of worms from the biliary tract. The ease of diagnosis and therapy in the same setting makes ERCP particularly valuable when used with real-time ultrasonography. The combined procedures yield a sensitivity of nearly 100%.[19]

Contributor Information and Disclosures

David R Haburchak, MD, FACP Professor of Medicine, Medical Director of Physician Assistant Program, Department of Medicine, Section of Infectious Diseases, Medical College of Georgia at Augusta University

David R Haburchak, MD, FACP is a member of the following medical societies: American College of Physicians, American Society for Microbiology, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Richard B Brown, MD, FACP Chief, Division of Infectious Diseases, Baystate Medical Center; Professor, Department of Internal Medicine, Tufts University School of Medicine

Richard B Brown, MD, FACP is a member of the following medical societies: Alpha Omega Alpha, American College of Chest Physicians, American College of Physicians, American Medical Association, American Society for Microbiology, Infectious Diseases Society of America, Massachusetts Medical Society

Disclosure: Nothing to disclose.

Chief Editor

Pranatharthi Haran Chandrasekar, MBBS, MD Professor, Chief of Infectious Disease, Program Director of Infectious Disease Fellowship, Department of Internal Medicine, Wayne State University School of Medicine

Pranatharthi Haran Chandrasekar, MBBS, MD is a member of the following medical societies: American College of Physicians, American Society for Microbiology, International Immunocompromised Host Society, Infectious Diseases Society of America

Disclosure: Nothing to disclose.

Additional Contributors

Jeffrey D Band, MD, FACP, FIDSA Professor of Medicine, Oakland University William Beaumont School of Medicine; Health System Chair, Healthcare Epidemiology and International Medicine, Beaumont Health System; Former Chief of Infectious Diseases, Beaumont Hospital; Clinical Professor of Medicine, Wayne State University School of Medicine

Disclosure: Nothing to disclose.

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Adult Ascaris lumbricoides.
Life cycle of Ascaris lumbricoides.
Ascaris lumbricoides egg.
Adult Ascaris lumbricoides in biliary system.
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