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Trypanosoma cruzi in southwest Georgia raccoons Berrien R. Waters and J. Mitchell Lockhart Department of Biology Valdosta State University Valdosta, Georgia
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Trypanosoma cruzi - Background Protozoan parasite Most Trypanosoma species are HETEROXENOUS - living within more than one host during their life cycle
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Trypanosoma cruzi - Background During one stage, they live in the blood and/or fixed tissues (may be intracellular) of all classes of vertebrates. During other stages, they live in the intestines (gut) of blood-sucking invertebrates.
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Trypanosoma cruzi - Background Individuals usually pass through different morphological stages, depending on the phase of their life cycle and type of host. TrypomastigoteAmastigoteEpimastigote
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Trypanosoma cruzi - Background LIFE HISTORY Hemiptera (true bugs) in the Family Reduviidae are the vectors. Common name - Kissing bugs Feed on humans by piercing the skin. T. cruzi is transmitted to the host after the bug defecates on the skin of the host while feeding. Parasites migrate into the open wound.
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Trypanosoma cruzi - Life Cycle
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Engorged Reduviid
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Trypanosoma cruzi - Background Causative agent of Chagas disease. Infects 16-18 million people. > 50,000 deaths each year. In the United States, but probably a much less pathogenic strain.
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Trypanosoma cruzi - Epidemiology Kissing bugs - vector. Domestic and wild mammals can be reservoirs. Dogs and cats are the most important for human infections in endemic areas. Others found infected in the U.S. - raccoons, armadillos, opossums, rodents, bats, non-human primates, skunks, and gray fox.
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Trypanosoma cruzi - Epidemiology Sampling of previous raccoon studies 1.5% - GA/FL (McKeever et al., 1998) - C 15% - NC (Karsten et al., 1992) - C 22.2% - GA - (Pung, 1995) - C 50-60% - GA/SC - (Yabsley et al., 2002) - PCR 63% - OK (John and Hoppe, 1986) - C
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Trypanosoma cruzi - Control Kissing bugs are nocturnal, hiding by day. Poor housing with thatched roofs, cracked walls, or trash-filled rooms provide ideal hiding conditions for the bugs. Control methods have NOT been very successful.
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Trypanosoma cruzi in southwest Georgia United States Department of Agriculture - Wildlife Services study to evaluate the effect of mesomammalian predator removal on bobwhite quail reproduction (2001-2006). Principals USDA-Wildlife Services University of Georgia Auburn University Tall Timbers Research Station, Florida Valdosta State University - 2003
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Trypanosoma cruzi in southwest Georgia Predators were removed from four southwest Georgia/north Florida quail plantation sites. Study now includes Florida site. Included raccoons, opossums, foxes, armadillos, coyotes, feral dogs, feral cats, and bobcats Animals were necropsied at VSU. Various tissue samples and data were collected.
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Trypanosoma cruzi in southwest Georgia 352 frozen raccoon heart tissue samples were evaluated for the presence of Trypanosoma cruzi by polymerase chain reaction (PCR). Frozen samples were thawed and DNA isolations were performed utilizing Qiagen DNeasy™ tissue kits according to the manufacturer’s protocol. PCR conditions and target as given in J. Gillis presentation.
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Trypanosoma cruzi in southwest Georgia 2003 Pebble Hill - 18/55 = 32.7% PB-East - 18/95 = 18.9% Chi square = 2.91, df=1, NSD
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Trypanosoma cruzi in southwest Georgia 2004 TTRS - 22/89 = 24.7% PB-West – 28/113 = 24.8% Chi Square = 0.52, df=1, NSD 2003 (24.0%) versus 2004 (24.8%)
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Trypanosoma cruzi in southwest Georgia By sex Males – 49/240 = 20.4% Females – 37/111 = 33.3% Chi square = 146.06, df=1, Significant difference, p > 0.005.
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Trypanosoma cruzi in southwest Georgia N 891705957291424
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Trypanosoma cruzi in southwest Georgia Conclusions Trypanosoma cruzi is present in raccoons in the Red Hills plantation region of southern Georgia/northern Florida. No significant differences exist in the sites studied to date. A statistically significant difference exists in the level of T. cruzi infection between raccoon sexes. Why?
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Trypanosoma cruzi in southwest Georgia Future Directions: Evaluate 2 additional years of data Evaluate age data PCR vs. serology vs. culture isolation? Other mesomammalian species? Management practices?
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Trypanosoma cruzi in southwest Georgia Acknowledgements Sarah Brantley USDA - Wildlife Services University of Georgia Auburn University Tall Timbers Research Station Valdosta State University Student and Faculty Development Funds
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Questions?
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