Poster #438 Contact: Devyn K. Stek St. Teresa of Calcutta Education Center 256 Swamp Pk., Schwenksville, PA 19473 1 610-850-2476 Devyn K. Stek [email protected] Finding Toxocara Eggs in Park Soil from Montgomery County, Pennsylvania, USA 1 St. Teresa of Calcutta Education Center, Schwenksville, PA, USA

BACKGROUND IMPACT ON HUMANS STUDY PROCEDURES RESULTS STUDY LIMITATIONS

• Toxocara spp. is a parasite commonly known as roundworm 1 • Toxocara spp. infection in humans is called toxocariasis 1 Due to their similar appearance and size, no differentiation • Identify parks (Table 1) Figure 4. Distribution of Toxocara Eggs Figure 5. Average Number of Toxocara Eggs per Park (95% CIs) • between T. canis and T. cati was attempted during this study • Most common reservoirs are () and cats Children are more frequently infected (~30% in 6-11 year olds) than 2 • • Collect ~2 cups of dirt into a plastic bag () adults (~14%) 6-8 • There are many different types of roundworms whose eggs all • Dry and sift sample using a 1/32-inch opening mesh screen have similarities and differences – Other reservoirs: foxes, birds, pigs, rodents, goats, rabbits, – Higher likelihood of hand-to-mouth transmission of contaminated monkeys, and humans – Pinworms, Ascaris, , Strongyloides, Trichinella, soil by kids Add 2 tablespoons of sifted soil to glass • whipworm, and • Toxocara eggs are spherical to oblong, with a rough/pitted edge, and 9 • Most infections have no symptoms and clear by themselves • Add 1/4 cup of sugar floatation solution and stir 11 brownish in color (Figure 1) • A lack of formal parasitology training could have resulted in counting the wrong egg as Toxocara – 75-90 µm (T. canis) or 65-70 µm (T. cati) 3,4 • Symptoms include weight loss, malaise, fever, fatigue, and failure • Let mixture sit for 1 hour to grow 9 • Transfer supernatant to a 20 mL tube and cap • Toxocara has a predictable life cycle 5 (Figure 2) CONCLUSIONS • Worms can move anywhere in the body 10 Let tube sit overnight • • Toxocara eggs were found in every park tested – Visceral migrans (VLM) = worm moving under skin • Pipette 3 drops of surface fluid onto a glass slide and cover – Soil sifting and the floatation technique with a sugar Figure 1. Toxocara Eggs – Ocular larva migrans (OLM) = worm moving in eye • Examine the slide under 400X total magnification solution was used = ~70 people in the US go blind from toxocariasis • Count and record the number of Toxocara eggs seen in a full grid search • The number of eggs per sample varied greatly – Highest amounts in areas that could contain food Table 1. Park and Sample Site Descriptions droppings (e.g. picnic area) or places that could serve Table 2. t-Distribution Test and 95% Confidence Interval (CI) as a convenient bathroom for dogs (e.g. tree grove) STUDY OBJECTIVE Determination Post-Study Analyses (credit: Misoo Ellison, PhD) • Some parks were significantly less infected than others • The primary objective: to examine and describe the contamination level of each park and sample for Toxocara eggs • Some, but not all, parks had similar average number of Toxocara eggs – Independent variable: different samples tested Table 4. Kruskal-Wallis Test on the Number of Figure 2. Toxocara spp. Life Cycle Toxocara Eggs Among Parks – Dependent variable: use of the floatation method with a sugar Acknowledgements solution to visualize Toxocara eggs using a microscope 11 • I would like to thank my school and my teachers, Mr. Dusza (science) and Ms. Robbins (math), for their support and guidance. • I would also like to thank my parents for their help and supervision of my work. Table 3. Chi-Square Test for Similarity/Difference • I would also like to recognize Dr. Misoo Ellison for her guidance on additional and future statistical analyses of my work.

STUDY QUESTIONS • I especially would like to acknowledge Steven Silberman, DVM of Affordable Spay and Neuter (Pottstown, PA) for providing a Toxocara-positive sample as a • Are Montgomery County parks infected with Toxocara eggs? reference for my microscope work.

• Can the float technique using a sugar solution be used to visualize References the number of Toxocara eggs in soil samples? Figure 3. Park Locations in Montgomery County, PA 1. Centers for Disease Control and Prevention. Parasites – Toxocariasis (also known as Roundworm Infection). Available at: https://www.cdc.gov/parasites/toxocariasis/ gen_info/faqs.html. Accessed: October 2, 2017. • What information can be learned from the number of Toxocara eggs RESULTS SUMMARY Table 5. Pair-wise Comparison on the Average Rank in each sample? between Parks using the Dunn Procedure 2. Marty AM. Toxocariasis Chapter 27, pages 411- 421 in Meyers WM, Neafie RC, • 35 of 36 samples tested positive for Toxocara eggs Marty AM, Wear DJ. (Eds) Pathology of Infectious Diseases Volume I: Helminthiases. • What comparisons can be made about the average number of Armed Forces Institute of Pathology, Washington DC. 2000. Toxocara eggs found in each park? • Parks and samples varied in levels of contamination (Figure 3) 3. Harris-Linton, M. Toxocara canis. Diversity Web. 2001. Available at: http:// animaldiversity.org/accounts/Toxocara_canis/. Accessed: October 2, 2017.

– Smallest samples (0 & 2 eggs) from Sanatoga Park 4. Peregrine AS. Roundworms in Small . The Merck Manual. 2017. Available at: http://www.merckvetmanual.com/?cfile=htm%2Fbc%2F23505.htm. Accessed: – Largest samples from Pottstown Memorial Park [52 eggs - picnic October 2, 2017. pavilion] and Heather Place Park [56 eggs - tree grove] STUDY HYPOTHESES 5. Centers for Disease Control and Prevention (DPDx). Toxocariasis. Available at: https://www.cdc.gov/dpdx/toxocariasis/index.html. Accessed: October 2, 2017. • Manderach Park (11.7 eggs [95% CI: 9.6, 13.8]) had significantly larger 6. Hermann N, Glickman LT, Schantz PM, Weston MG, Domanski LM. Seroprevalence • Toxocara eggs will be found in Montgomery County park soil average number of eggs compared to Sanatoga Park (2.5 eggs [95%CI: 1.0, of zoonotic toxocariasis in the United States: 1971-1973. Am J Epidemiol. samples 4.0]), Gerald Richards Park (4.0 eggs [95% CI: 3.8, 6.2]), and Althouse 1985;122(5):890-6. Arboretum (4.7 eggs [95% CI: 3.3, 6.1]) (Table 2A;Figure 4) 7. Jones JL, Kruszon-Moran D, Won K, Wilson M, Schantz PM. Toxoplasma gondii and • The float technique with a sugar solution will allow the visualization Toxocara spp. co-infection. Am J Trop Med Hyg. 2008;78(1):35-9. and counting of the number of Toxocara eggs in soil samples STUDY MATERIALS – Sanatoga, Gerald Richards, and Heather Place had similar average 8. Won KY, Kruszon-Moran D, Schantz PM, Jones JL. National seroprevalence and risk number of eggs (χ2=3.97 < 5.99) (Table 2B) factors for Zoonotic Toxocara spp. infection. Am J Trop Med Hyg. 2008;79: 552–557. • The number of Toxocara eggs in each sample will vary; certain NHS Choices. Toxocariasis. Available at: https://www.nhs.uk/conditions/ • Gardening trowel 9. • ~20 mL plastic tubes • Plastic pipettes areas may contain more eggs than others • Highest average number of eggs recorded from Pottstown Memorial Park Toxocariasis/. Accessed: October 2, 2017. (18.2 eggs [95% CI: 4.1, 32.1]) and Heather Place Park (18.5 eggs [95%CI: • Zip-lock plastic bags • Glass cups • Glass slides/cover slips 10. Kayes SG.Human toxocariasis and the syndrome: correlative • Some parks will have a greater average number of Toxocara eggs 3.5, 23.5]) (Table 2A; Figure 4) immunopathology. Chem Immunol. 1997;66:99-124. • Sieve • Floatation solution • Microscope than others 11. Ruiz de Ybanez MR, Garijo M, Govena M, Alfonso FD. Improved methods for – Both parks had very similar average number of eggs (χ2=0.02 <3.84) recovering eggs of Toxocara canis from soil. J Helminthol. 2000;74(4):349-53. (Table 2B)

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