Raccoon Roundworm in Florida

A Study of Raccoon Roundworm in Florida - Baylisascaris procyonis is the formal name given to the roundworm infection found in raccoons. This intestinal parasite is communicable to humans. Health risks like this are one of the reasons why you should never tolerate a raccoon infestation of your home. People think that “out of sight, out of mind” is acceptable when it comes to nuisance animals, but the reality is they can harbor some serious illnesses that are dangerous to people. Roundworms live in the intestinal tract. Their eggs are microscopic and are easily transmitted from one host to another. It only takes one roundworm egg on your hand to make its way into your mouth and down into the area where it can grow and create trouble. While a roundworm infestation probably won’t kill you, it will make you very sick. Children have the most to worry about when it comes to parasite infection. A roundworm in a child will sometimes migrate up to the eyes and cause blindness. Unfortunately, many of these parasites exhibit symptoms like some viral diseases, causing parents to wait longer than they should to seek medical attention.

I was forwarded the following article about raccoon roundworm in Florida, and so I've decided to help spread the word:

Recently the raccoon roundworm (Baylisascaris procyonis) was detected in Florida (northwestern - near Tallahassee and southeastern - near Ft. Lauderdale). Attached is a recently accepted manuscript describing this report. Also attached are educational brochures (still need to update to include Florida!) that discuss B. procyonis.

In collaboration with the Florida Fish and Wildlife Conservation Commission, the Florida Department of Health, and the Centers for Disease Control and Prevention, we are conducting surveillance for this important zoonotic parasite. We are asking numerous agencies and private citizens to assist with this effort, including wildlife nuisance operators. This effort will be ongoing and will be conducted throughout Florida but we are particularly interested in southern Florida.

There are several ways that participants can assist - 1) by submission of frozen raccoon carcasses (>4 mo old) that are euthanized or freshly roadkilled, 2) submission of frozen intestines that have been removed from euthanized or road-killed animals, or 3) submission of preserved feces.

Please contact me if you are interested in participating and I can send collection vials or instructions for submission of samples. We appreciate your help! We will continue to update participants with our findings and provide guidance regarding disinfection protocols to prevent risks regarding spreading B. procyonis as well as concerns regarding exposure of you or your personnel to this parasite.

Baylisascaris procyonis is a common parasite of raccoons (Procyon lotor) in several regions of North America, Europe, and Asia. This parasite is increasingly being recognized as an important cause of larva migrans in humans and infection often results in mortality or severe neurologic sequelae. In addition, larva migrans have been documented in >90 species of wild and domestic birds and mammals. In the United States, the highest prevalence rates are in the Midwestern, northeastern, and Pacific western states. Although numerous surveillance studies have been conducted in the southeastern United States, B. procyonis is most common in mountainous regions of Virginia, Kentucky, and West Virginia (1, 2, 3, 4). Geographic expansion of B. procyonis has been recently documented in Georgia. In 2002, 22% of raccoons from DeKalb Co. Georgia, a highly urbanized area near Atlanta were positive (5) and recently 10% of raccoons from Clarke Co. Georgia were positive (6). It is currently unclear whether this expansion is due to a natural spread of the parasite among raccoons or translocations of infected raccoons into naive areas.

In the current letter, we document a range expansion of B. procyonis into northwestern and southeastern Florida. From 2006 to 2008, nine nematodes (>3 inches) were collected from the feces of an unrecorded number of raccoons admitted to a rehabilitation center in northern Florida. In September 2008, December 2009, June 2010, a single ascarid was found in the feces of two juvenile (4 and 6-mo-old) raccoons from Leon County, Florida and one juvenile (6-mo-old) raccoon from Wakulla County, Florida following routine treatment with pyrantel pamoate (20 mg/kg). In July 2010, a juvenile (6-mo-old) raccoon from Broward County admitted to a rehabilitation center passed several worms (2 collected for testing) in its feces following ivermectin treatment (0.2mg.ml) for mange. The 14 worms were preserved in 70% ethanol and adult males were identified as Baylisascaris based on morphologic characteristics (perianal rough patches). Worms were subsequently confirmed as B. procyonis by sequence analysis of the 5.8S rRNA gene and /or the internal transcribed spacer (ITS)-1 and ITS-2 regions (7, 8). The complete sequences of the 5.8S rRNA gene and ITS-2 region from two northern Florida worms and one southern Florida worm were identical to B. procyonis (Genbank AJ001501 and AB051231, respectively). ITS-1 sequences from two north and south Florida worms were 99.1% (424/428; AB053230) to 100% identical (AJ00745 and worms from Georgia, Kentucky, and Texas [6]), respectively, to B. procyonis.

Several previous studies failed to detect B. procyonis in raccoons or latrine sites from several locations in central Florida (n=51, Glades, Highlands, Hillsborough, and Orange Counties), southern Florida (n=90 from around Miami and n=64 fecal samples on Key Largo), and numerous counties throughout Florida (n=177), (1, 3,9). Historically, B. procyonis has been absent throughout most of the Southeast, but B. procyonis was recently detected in north-central Georgia (5, 6). It remains unclear how the parasite became established in Florida but could be from natural dispersal of infected raccoons from endemic areas although recent examination of several raccoon populations in southern Georgia failed to detect infections (6). Alternatively, introduction could have been from the movement of infected raccoons, exotic pets (e.g., kinkajou (Potos flavus)), or natural wildlife intermediate hosts (1). Additionally, because domestic dogs can serve as definitive hosts, an infected dog from a B. procyonis endemic area may have passed eggs into the environment (1). Veterinarians in Florida should be aware of this possible zoonosis and conduct careful examination of ascarid eggs detected in fecal exams as B. procyonis-infected dogs often have mixed infections with Toxocara canis and/or Toxascaris leonina which have morphologically similar eggs (1).

This study highlights the importance of wildlife rehabilitation centers as resources for the study of wildlife/zoonotic diseases. Animals admitted to rehabilitation centers are often ill or injured, which may increase pathogen shedding or transmission. Additionally, young raccoons are more likely to be infected with B. procyonis and kits as young as 3 months old can be patent. Importantly, there have been numerous fatal B. procyonis larva migrans among animals in rehabilitation centers and zoological parks which were likely acquired when animals were housed in enclosures that were previously occupied by infected raccoons or when bedding or food have become contaminated with B. procyonis-infected raccoon feces. In endemic areas, cages used to house raccoons should be thoroughly decontaminated by flaming or cages should be dedicated for raccoons.

Because B. procyonis, as well as many other pathogens in wildlife, is zoonotic it is important that individuals in contact with raccoons be aware of potential transmission routes and appropriate biosecurity procedures. Importantly, physicians, veterinarians, and wildlife biologists in Florida should be aware of this important pathogen and that its range will likely increase, as highlighted by the recent detection of B. procyonis in a kinkajou from southern Florida.

If you want to see photographs, click here for raccoon droppings and feces identification.

The drug Albendazole is said to be effective in treating raccoon roundworm.