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Trypanosoma cruzi in southwest Georgia raccoons

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

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Trypanosoma cruzi in southwest Georgia raccoons

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

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

  3. Trypanosomacruzi - 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. Trypanosomacruzi - Background • Individuals usually pass through different morphological stages, depending on the phase of their life cycle and type of host. Trypomastigote Amastigote Epimastigote

  5. Trypanosomacruzi - 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. Trypanosomacruzi - Life Cycle

  7. EngorgedReduviid

  8. Trypanosomacruzi - 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.

  9. Trypanosomacruzi - 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.

  10. Trypanosomacruzi - 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

  11. Trypanosomacruzi - 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.

  12. Trypanosomacruzi 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

  13. Trypanosomacruzi 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.

  14. Trypanosomacruzi in southwest Georgia • 352 frozen raccoon heart tissue samples were evaluated for the presence of Trypanosomacruzi 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.

  15. Trypanosomacruzi in southwest Georgia • 2003 • Pebble Hill - 18/55 = 32.7% • PB-East - 18/95 = 18.9% • Chi square = 2.91, df=1, NSD

  16. Trypanosomacruzi 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%)

  17. Trypanosomacruzi 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.

  18. Trypanosomacruzi in southwest Georgia

  19. Trypanosomacruzi in southwest Georgia • Conclusions • Trypanosomacruzi 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?

  20. Trypanosomacruzi 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?

  21. Trypanosomacruzi 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

  22. Questions?

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