Baylisascariasis: A Potential Local Threat Joshua Sabey BIOL 4800 Emerging Diseases • • • • • • • • HINI (Swine Flu) Avian influenza (Bird Flu) Severe acute respiratory syndrome (SARS) West Nile virus Bovine Spongiform Encephalopathy (Mad Cow) Staphylococcus aureus (Antibiotic Resistance) Plasmodium (Malaria) Baylisascaris procyonis (Raccoon Ascaris) Baylisascaris procyonis Eggs • Nematode • Dioecious • Thick cuticle Larvae Adults Life-Cycle Life-Cycle Specifics • Final host is Raccoon. • Has a wide range of intermediate hosts including birds, squirrels, woodchucks, and rabbits. • Larvae can also infect humans and cause major problems. Raccoon Range Raccoon Range Expansion • • • • • Raccoon harvest 1000 pelts or more MB = 1967 SK = 1972 AB = 1983 Expansion Reasons 1. Anthropogenic Resources • Food availability (Garbage and food crops). • Den availability (Trees in parks or yards, chimneys, and attics). 2. Global Warming • Longer growing season = more food. • Mild winters = increased hibernation survival. Raccoon Problems • Average 20,000 eggs per gram of feces. • Also common carriers of rabies and canine distemper. The Urban Raccoon Raccoon Latrines Prevalence in Urban Areas • Percentage of yards surveyed that had latrines: Chicago = 51%, San Jose = 49%. • Percentage of latrines surveyed that were infective: Winnipeg = 50%, San Jose = 53%. • Percentage of captured individuals that were infected: Winnipeg = 50%. • Some areas in Florida have an infection rate of up to 82%. Pathology CLM VLM OLM • Children are at highest risk by playing in yards and parks. Pathology • Baylisascaris procyonis larval migration is more aggressive. • Larvae are larger and grow during migration. • Results in more damage to tissues. • Releases toxic proteins causing inflammation. • CLM = intense itching. • VLM = abdominal pain. • OLM = partial or total loss of vision. NLM Initial Picture 2 Weeks Later 6 Weeks Later • Encephalitis: inflammation of the brain. • Progressive neurological decline. • Treatment does not prevent damage. Treatment • OLM are treated through surgical removal or direct laser photocoagulation. • All other LM are treated with antihelminthic medications. • Despite treatment, there are no documented neurologically intact survivors of NLM. • 40% of documented cases were fatal. • 73% of documented cases were children under 3. Conclusions • Raccoon range expansion North and West into Canada is making baylisascariasis a potential local problem. • Increased Raccoon populations in urban areas are increasing human exposure rates. • Since treatment is not effective, emphasis should be put on prevention of exposure. References Gavin PJ, Kazacos KR, and Shulman ST (2005). Baylisascariasis. Journal of Clinical Microbiology. 18:703718. Lariviere S (2004). Range expansion of raccoons in the Canadian prairies: review of hypotheses. Wildlife Society Bulletin. 32:955-963. Mehta P, Boyd Z, and Cully B (2010). Raccoon roundworm encephalitis. Pediatric Radiology. 1836. 11:1834- Page LK, Anchor C, Luy E, Kron S, Larson G, Madsen L, et al. (2009). Backyard raccoon latrines and risk for Baylisascaris procyonis transmission to humans. Emerging Infectious Diseases. 15:1530-1531. Roussere GP, Murray WJ, Raudenbush CB, Kutilek MJ, Levee DJ, and Kazacos KR (2003). Raccoon roundworm eggs near homes and risk for larva migrans disease, California communities. Emerging Infectious Diseases. 9:1516-1522. Sexsmith JL, Whiting TL, Green C, et al. (2009). Prevalence and distribution of Baylisascaris procyonis in urban raccoons (Procyon lotor) in Winnipeg, Manitoba. Canadian Veterinary Journal. 8:846-850. Shafir SC, Wise ME, Sorvillo FJ, et al. (2006). Central nervous system and eye manifestations of infection with Baylisascaris procyonis. Current Infectious Diseases Report. 4:307-13.