Egg Production in the Raccoon Roundworm, Baylisascaris procyonis

The raccoon roundworm, Baylisascaris procyonis, is a parasitic nematode that matures in raccoons (Procyon lotor). The larval stage of this parasite is capable of infecting humans, causing a potentially fatal disease known as baylisascariasis, which has recently been recognized as an emerging zoonosis. In raccoons, individual worms can produce extraordinary quantities of eggs and it is these eggs that are infective to humans and other wildlife. A variety of factors may lead to variation in the number of eggs produced by an individual worm; the purpose of this research is to determine the relationship between female B. procyonis size, uterus size and egg production. Worms were removed from the intestines of raccoons, measured and then the uterus was removed from the worm and measured as well. The uterus was homogenized in a known quantity of water and filtered. We then counted the number of eggs in a one milliliter aliquot of well mixed solution and used this value to calculate the total number of eggs per worm. Our work shows that there is a correlation between female B. procyonis size, uterus size, and egg quantities produced. Understanding the factors that control egg production in this parasite will help determine the potential for roundworm infection among animals as well as humans and ultimately increase our understanding of transmission and spillover of zoonotic disease agents.