Suspected case of a rare disease linked to raccoon roundworms

home_page_image_baylisascaris CDC
photo: CDC

UPDATE 05/9/17: Results came back from the CDC today indicating that the child tested positive for Baylisascaris.

Original post from 05/08/17:

Health experts suspect that a King County toddler may have contracted Baylisascaris infection, a very rare disease associated with accidental ingestion of roundworm eggs found in dirt or other substances that have been contaminated by raccoon droppings. The Centers for Disease Control and Prevention (CDC) is testing specimens from the child’s blood and spinal fluid and results are expected in two weeks. The toddler was hospitalized but is now recovering at home.

A rare and severe infection

Only 29 cases of Baylisascariasis have been reported in the U.S. since 1973 and no cases have ever been reported in Washington State. People can become infected if they inadvertently swallow dirt or materials contaminated with raccoon droppings that contain microscopic Baylisascaris roundworm eggs. The roundworm larvae can hatch inside a person and travel throughout the body. The infection can be severe and even fatal if the roundworms enter a person’s eye, organs, or brain. Baylisascariasis does not spread person-to-person.

Young children are at the highest risk for infection because they are more likely to put contaminated objects or fingers in their mouths, or eat contaminated dirt, sand, or other material.

Stay away from raccoons and their latrines

To prevent infection, wash your hands after working or playing outdoors and avoid areas that are frequented by raccoons, especially “raccoon latrines.” A raccoon latrine is a site where raccoons repeatedly deposit their droppings. Fresh droppings usually are dark and tubular, have a pungent odor (usually worse than dog or cat feces), and often contain undigested seeds or other food items (go to the CDC page for photos). Raccoons prefer sites that are flat and raised off the ground, but they also use the base of trees, and occasionally, open areas. Common sites for raccoon latrines are roofs, decks, unsealed attics, haylofts, the raised forks of trees, fence lines, woodpiles, fallen logs, and large rocks.

You can prevent having a raccoon latrine on your property by discouraging raccoons from frequenting your outdoor living space:

girl_playing_dirt CDC
Raccoons may use sandboxes as a latrine. Keep them covered when not in use. (photo: CDC)

If you discover a raccoon latrine on your property, keep children and pets away from that area. Cleaning the area may prevent possible infection. Newly deposited eggs take at least 2-4 weeks to become infectious. You can reduce the risk of exposure and possible infection if you promptly remove raccoon droppings after you find them.

Special precautions should be used while cleaning to prevent contaminating yourself and other surfaces or accidentally swallowing any roundworm eggs. See the CDC web site for details https://www.cdc.gov/parasites/baylisascaris/prevent.html

Public Health’s Diseases from Raccoons and Other Wildlife webpage has more information about what raccoon latrines look like. You can also contact an experienced wildlife control service for help cleaning up latrines and removing problem raccoons. Refer to the directory of Nuisance Wildlife Control Operators trained and certified by the Washington Department of Fish & Wildlife.

Baylisascariasis and pets

Do not keep, feed, or adopt wild animals, including raccoons, as pets! Infection rarely causes symptoms in raccoons, so you cannot tell if a raccoon is infected by observing its behavior.

Dogs can be infected with the Baylisascaris roundworm, but it is rare. Have all pets de-wormed under a veterinarian’s supervision and take precautions to avoid contact with their feces. Talk to your veterinarian if you have any concerns about Baylisascaris and your dog.

More information from the CDC: https://www.cdc.gov/parasites/baylisascaris/

Originally posted on May 8, 2017.

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I am a risk communications specialist at Public Health - Seattle & King County.