Date of Graduation

5-2023

Document Type

Thesis

Degree Name

Bachelor of Science in Agriculture

Degree Level

Undergraduate

Department

Animal Science

Advisor/Mentor

Dowling, Ashley

Committee Member/Reader

Coffey, Kenneth P.

Committee Member/Second Reader

McDermott, Emily

Abstract

Within the past few decades, the number of diagnoses of tick-borne diseases – such as spotted fever rickettsiosis and ehrlichiosis – has steadily increased throughout the United States, with Arkansas having one of the highest rates in the country. These diseases pose a risk to both humans and animals, as both can acquire these infections from ticks. Due to the increasing geographic range of ticks, rise in cases, and likely underdiagnosis of these diseases, this study aimed to identify the infection rate of ticks themselves in multiple state parks in Arkansas. Four Arkansas state parks were each visited once a month for four months, and ticks were collected through a combination of dragging and dry ice methods. A total of 1,255 ticks were collected, of which 1,021 were nymphs and 234 were adults. Twelve ticks were identified as Ixodes scapularis, and the other 1,243 were identified as Amblyomma americanum. Depending on the park, the total A. americanum adults infected ranged from 55% to 72% for Rickettsia, 2.65% to 25% for Ehrlichia ewingii, and 0% to 8.33% for Ehrlichia chaffeensis. The total A. americanum nymphs infected ranged from 20.11% to 21.67% for Rickettsia, 0.27% to 1.78% for E. ewingii and from 0% to 1.67% for E. chaffeensis. The proportion of ticks infected with these pathogens did not significantly vary from park to park, but there was a significant association between the parks and sample size for dragging, indicating tick density varied significantly from park to park. This study demonstrates the high risk of tick-borne disease within Arkansas and that tick density varies substantially (P < 0.02) within the state.

Keywords

Entomology; Pathogens; Vector-borne; Veterinary; Zoonotic

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