Parasitology, Harold W. Manter Laboratory of


Date of this Version



Kazacos, K.R., 2016, Baylisascaris Larva Migrans: U.S. Geological Survey Circular 1412, 122 p., 3 appendixes,
ISSN 2330-5703 (online)
ISBN 9781411340299


US government publication


Zoonotic diseases, such as baylisascariasis, are receiving increasing attention as components of disease emergence and resurgence (Kazacos, 2001). Baylisascariasis is caused by the roundworm Baylisascaris procyonis and is one of the more recent zoonotic disease developments. This disease remains one of the least known and poorly understood zoonotic diseases, yet over the past several decades it has become widespread. It originated in wildlife species and is now well established as a human malady. Baylisascariasis is transmitted to humans via consumption of contaminated feces, and the role of wildlife (primarily raccoons) in this transmission process is becoming more clearly known and is outlined in this report. Currently, over 50 percent of the raccoons in the United States are infected, and a smaller percentage in Europe is infected. Because raccoons have been relocated from the United States to Europe and Asia, this zoonotic disease also causes problems in wildlife species across the globe as well as being a major cause of concern for human health. Future generations of humans will continue to be jeopardized by Baylisascaris infections in addition to many of the other zoonotic diseases that have emerged during the past century. Through monitoring Baylisascaris infection levels in wildlife populations, we will be better able to predict future human infection levels of this important zoonotic disease.