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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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Presentation on theme: "Trypanosoma cruzi in southwest Georgia raccoons Berrien R. Waters and J. Mitchell Lockhart Department of Biology Valdosta State University Valdosta, Georgia."— Presentation transcript:

1 Trypanosoma cruzi in southwest Georgia raccoons Berrien R. Waters and J. Mitchell Lockhart Department of Biology Valdosta State University Valdosta, Georgia

2 Trypanosoma cruzi - Background  Protozoan parasite  Most Trypanosoma species are HETEROXENOUS - living within more than one host during their life cycle

3 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.

4 Trypanosoma cruzi - Background  Individuals usually pass through different morphological stages, depending on the phase of their life cycle and type of host. TrypomastigoteAmastigoteEpimastigote

5 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.

6 Trypanosoma cruzi - Life Cycle

7 Engorged Reduviid

8 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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10 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.

11 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

12 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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14 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

15 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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18 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.

19 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

20 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%)

21 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.

22 Trypanosoma cruzi in southwest Georgia N 891705957291424

23 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?

24 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?

25 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

26 Questions?


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