Raccoon Roundworm

    The raccoon roundworm (Baylisascaris procyonis) is the common large roundworm or ascarid found in the small intestinal tract of raccoons. Prevalence of infections ranges from 3.4% to nearly 100% of all raccoons sampled. Transmission of B. procyonis can occur either directly or via an abnormal host. In the direct life cycle, eggs of Baylisascaris from an infected raccoon are shed in the feces and, within 30 days, a larval stage will develop within the egg (embryonated). Raccoons, especially young ones, become infected directly by accidental ingestion of the eggs. This may occur via the mother’s egg-contaminated body or from the local environment of the den (soil or vegetation). When an abnormal host is involved, embryonated eggs are ingested, the eggs hatch, and the larvae penetrate the intestines and migrate through the liver and lungs. They then continue on random migrations that can lead them to the head, neck and/or chest. The larvae finally become encysted in small fibrous nodules in the muscle, liver or lungs. If the abnormal host is eaten by a raccoon, the encysted larvae are released and migrate to the small intestine where they develop to the adult stage.

In raccoons usually there are no clinical or pathological signs observed. In heavy infections, intestinal obstructions or a rupture of the intestinal tract may occur, due to the large number of parasites present. The animals usually seen with clinical and pathological signs caused by Baylisascaris are the abnormal hosts (mice, woodchucks, squirrels, rabbits, birds, and even humans). Migration of large numbers of larvae may cause liver and lung damage. Usually changes in behavior are seen due to central nervous system disorders. This is the result of damage caused to the brain and spinal cord by the larvae. Larvae may also cause eye disorders by migrating through the ocular tissues. If small numbers of larvae are involved in the migration, there may be no clinical signs observed.

In humans, pathological lesions observed consist of skin irritations (cutaneous larval migrans) and eye and brain tissue damage (visceral larval migrans) due to the random migration of the larvae. The affected individuals may experience nausea, a lethargic feeling, incoordination and loss of eyesight.

Tularemia

    Tularemia, or rabbit fever, is a bacterial disease associated with both animals and humans. Although many wild and domestic animals can be infected, the rabbit is most often involved in disease outbreaks. Tularemia is relatively rare in Massachusetts. The most common transmission from host to human is through the bite of an infected tick, contact with fluids from infected deer flies or ticks, or handling or eating insufficiently cooked rabbit meat. Less common means of spread are drinking contaminated water, inhaling dust from contaminated soil or handling contaminated pelts or paws of animals. Tularemia is not spread from person to person. Symptoms vary, depending on the route of introduction. In those cases where a person becomes infected from handling an animal carcass, symptoms can include a slow-growing ulcer at the site where the bacteria entered the skin (usually on the hand) and swollen lymph nodes. If the bacteria is inhaled, a pneumonia-like illness can follow. Those who ingest the bacteria may report a sore throat, abdominal pain, diarrhea and vomiting. Symptoms can appear between one and 14 days after exposure, but usually do so after three to five days, however antibiotics such as streptomycin or gentamicin are highly effective.

Giardia

    Giardiasis, also known as Beaver Fever is a diarrheal illness caused by a one-celled, microscopic parasite. The Giardia parasite lives in the intestine of infected humans or animals, but most commonly the beaver in Massachusetts. Millions of germs can be released in a bowel movement from a beaver. Giardia is found in soil, food, water, or surfaces that have been contaminated with the feces from beavers. You can become infected after accidentally swallowing the parasite; you cannot become infected through contact with blood. You can contract it by accidentally putting something into your mouth or swallowing something that has come into contact with feces of a person or animal infected with Giardia, or swallowing recreational water contaminated with Giardia. Recreational water includes water in swimming pools, hot tubs, jacuzzis, fountains, lakes, rivers, springs, ponds, or streams that can be contaminated with sewage or feces from humans or animals. The symptoms of Giardia are quite unpleasant and include: Diarrhea, bloating, greasy stools, stomach cramps, and nausea. These can lead to severe weight loss and dehydration. Symptoms of giardiasis normally begin 1 to 2 weeks (average 7 days) after becoming infected, and can last up to 6 weeks, sometimes even longer.

Lyme Disease

    Lyme disease is caused by a bacteria transmitted to humans by the bite of infected blacklegged or deer ticks. Typical symptoms include fever, headache, fatigue, and a characteristic (bullseye) skin rash called erythema migrans. If left untreated, infection can spread to joints, the heart, and the nervous system. Lyme disease is diagnosed based on symptoms, physical findings (e.g., rash), and the possibility of exposure to infected ticks; laboratory testing is helpful in the later stages of disease. Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics. Steps to prevent Lyme disease include using insect repellent, removing ticks promptly, landscaping, and integrated pest management. The ticks that transmit Lyme disease can occasionally transmit other tick-borne diseases as well.