Adult Baylisascaris procyonis removed from the small intestine of a raccoon. Adult females (left) are about 24 cm long; males (right) are about 12 cm long. (Reprinted from Clinical Microbiology Newsletter 2002;24:1–7; with permission from Elsevier Science).

Typical raccoon latrines found in urban/suburban environments. (A) Latrine on a chimney ledge, illustrating the climbing abilities of raccoons and their tenacity in maintaining latrines. (B) Large latrine in the crotch of an oak tree approximately 3.5 m (15 feet) above ground. The sides of the tree were visibly stained with fecal residue that rain had washed down the trunk, contaminating a child’s play area below with Baylisascaris procyonis eggs. (C) Large latrine, in use for years on a house roof, unknown to the home owner. (D) Latrine site on the ground near downed timber and rocks in a suburban yard. Note the variety of fecal materials (including seeds, crustacean shells, and human refuse), reflecting the diversity of the raccoon diet. The homogenous-appearing fresh scat in the center is composed of digested pet food. (E) Latrine on a stump in a suburban park with plants sprouting from seeds in the scat. Granivorous birds and mammals are attracted to such locations, as are curious children. (F) Raccoon scat hidden in leaf litter in a suburban back yard, indicating how occult contamination may be.

Baylisascaris procyonis eggs recovered from raccoon feces from a latrine in a playground sandbox. Left, infective egg containing a fully formed larva (40x). Right, an undeveloped or degenerate noninfective egg. B. procyonis eggs are ellipsoid, approximately 75 μm x 60 μm in size, with a brown, finely granular surface. (Reprinted from Clinical Microbiology Newsletter 2002;24:1–7; with permission from Elsevier Science.)

Percentage of raccoon latrines found at various locations in Pacific Grove, Carmel, and San Jose, CA (number of latrines = 244). The “other” category includes window ledges, attics, fences, decks, and so forth.

Percentage of raccoon latrines that tested positive for Baylisascaris procyonis eggs and those containing potentially infective eggs (number of latrines = 215).

Percentage of properties that contained at least one raccoon latrine positive for Baylisascaris procyonis eggs (number of properties = 164).

Frequency distributions for the number of raccoon latrines found in Pacific Grove, Carmel, and San Jose, California.