Case Study #4

Matt IgleskiNeil Schock

*Note missing head this is important later in the talk

Introduction

• TaxonomyFamily: Cervidae

White-Tailed DeerOdocoileus virginianus

• Range: North America

• Importance:– Recreation– Commercial

List of Possible Protozoal infections

• Toxoplasmosis– Intermediate host

• Neosporosis– Member of Sylvatic cycle– Seroprevalence

• 40% in IL• 19% in WI

• Cryptosporidium– Virginia- fecal samples (Rickard et al. 1999)

• Oocytes in 5-8.8% of samples

Test• Brain tissue from hunter killed deer

• Heads shipped to USDA laboratory

• 50 g of brain tissue homogenized then digested with trypsin enzyme

• Digest injected subcutaneously into mice

• 5 mice inoculated for each deer

Results

• 58 deer were positive for parasite

• 25 of 28 groups of mice were asymptomatic

• Only 3 groups of mice became ill according to histopathology

• 28 total mice were positive according to immunochemistry

Results

Histopathology• Tachyzoites found in lung tissue of 5 mice, 10

total mice infectedImmunochemistry• Heart

– 23 mice with positive infection• Pancreas

– 9 mice with positive infections• Other organs affected

– Gall bladder, brain, lung, liver , intestines, ovaries, aorta, stomach, and kidneys

Predominant lesion• Non-suppurative myocarditis

– No pus, inflammation of heart

Focus of necrosis in heart. Two cyst structures

Diagnosis

Toxoplasmosis– Causes tissue necrosis– Immune response drives parasite into tissue

cyst form– Both symptoms present in this study

Neosporosis– Forms cyst in tissue– One symptom present in this study