Skip Navigation LinksSkip Navigation Links
Centers for Disease Control and Prevention
Safer Healthier People
Blue White
Blue White
bottom curve
CDC Home Search Health Topics A-Z spacer spacer
Blue curve MMWR spacer

Epidemiologic Notes and Reports Intestinal Perforation Caused by Larval Eustrongylides -- Maryland

CDC recently received reports that three fishermen in Baltimore, Maryland, swallowed live minnows and developed severe abdominal pain within 24 hours.

Patient 1, a 23-year-old male, was seen at a community hospital on March 21, 1982, 2 days after swallowing two live minnows, because of progressive abdominal cramping pain of 24-hours' duration. During surgery, two roundworms were found, one penetrating the cecum, the other in the abdominal cavity. The transverse colon was found to be ecchymotic with punctate hemorrhage and exudates. On April 7, patient 2, a 25-year-old fisherman, was brought to the emergency room of the same hospital with similar symptoms 24 hours after swallowing one minnow. At laparotomy on April 9, two roundworms were found near a perforated cecum. Patient 3, a fisherman who swallowed minnows from the same source, later developed similar symptoms, which resolved 4 days later without surgery. Twelve other persons who also ingested live minnows reported no symptoms during 4 weeks of follow-up.

Sixty-seven minnows, collected in East Baltimore waters and secured from the same store at which the patients obtained their fish, were examined; 32 (48%) were infected with roundworms identical to those recovered from the two patients described above. Of the infected fish, six had two worms, one had three worms, and 26 had one worm each. The worms, 1-2 mm in diameter and 80-120 mm long, were identified as 4th-stage larval nematodes of the genus Eustrongylides.* Reported by PF Guerin, MD, S Marapudi, MD, L McGrail, RN, CL Moravec, MD, E Schiller, DSc, Baltimore, EW Hopf, MD, R Thompson, Baltimore County Health Dept, FYC Lin, MD, E Israel, MD, State Epidemiologist, Maryland State Health Dept; JW Bier, PhD, GJ Jackson, PhD, Bureau of Foods, Div of Microbiology, US Food and Drug Adminstration; Parasitic Diseases Div, Center for Infectious Diseases, CDC.

Editorial Note

Editorial Note: Nematodes of the genus Eustrongylides (Family Dioctophymidae Railliet, 1915) are parasitic as adults in the gastrointestinal tract of fish-eating birds and as larvae in the connective tissue or body cavity of freshwater fish (1). Amphibians, reptiles, and mammals (rarely) may become infected with larval Eustrongylides spp. and may play an ecological role as paratenic or transport hosts. Moreover, extensive larval migration in accidentally and experimentally infected reptilian, amphibian, and avian hosts has been observed and has sometimes been associated with high mortality (1-3), suggesting a possible pathologic role for Eustrongylides spp. However, no human infections have been reported to CDC.** Although data are incomplete, infection by larval Eustrongylides spp. is widespread and common in numerous species of freshwater fish. The high rates of infection for minnows (Fundulus spp.) reported here and earlier (3) may indicate a high degree of risk for persons who choose to eat these fish without cooking them first.


  1. Lichtenfels JR, Lavies B. Mortality in red-sided garter snakes, Thamnophis sirtalis parietalis, due to larval nematode, Eustrongylides sp. Lab Anim Sci 1976;26:465-7.

  2. Abram JB, Lichtenfels JR. Larval Eustrongylides sp. (Nematoda: Dioctophymatoidea) from otter, Lutra canadensis, in Maryland. Proceeding of the Helminthological Society of Washington 1974;41:253.

  3. Von Brand T, Cullinan RP. Physiological observations upon a larval Eustrongylides. V. The behavior in abnormal warmblooded hosts. Proceeding of the Helminthological Society of Washington 1943; 10:29-33. *Larval specimens have been deposited with the U.S. Department of Agriculture (USDA) in the U.S. National Museum, Helminthological Collection. **The USDA National Helminthological Collection contains a single larval specimen obtained from a human (2).

Disclaimer   All MMWR HTML documents published before January 1993 are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.

**Questions or messages regarding errors in formatting should be addressed to

Page converted: 08/05/98


Safer, Healthier People

Morbidity and Mortality Weekly Report
Centers for Disease Control and Prevention
1600 Clifton Rd, MailStop E-90, Atlanta, GA 30333, U.S.A


Department of Health
and Human Services

This page last reviewed 5/2/01