Date of Award

January 2024

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)

Department

School of Public Health

First Advisor

Douglas E. Brackney

Abstract

Introduction: Eastern equine encephalitis virus (EEEV), a mosquito-borne alphavirus, is detected throughout the eastern United States. The primary enzootic vector, Culiseta melanura (Blacktailed mosquito), allows transmission among 50+ avian host species resulting in complex disease patterns. Spillover to dead-end host mammals, such as equines and humans, rarely occurs, however, human cases can cause severe neurological deficits and have a 30% mortality rate. Eco-epidemiology and avian host immunity patterns are not well characterized for EEEV and require ongoing surveillance to develop more targeted interventions. Methods: Xeno-surveillance is an approach to survey EEEV through hematophagous arthropods, instead of collecting samples from a test population, in this case, avian species. Our goal was to develop an anti-EEE antibody screening assay as part of our mosquito surveillance pipeline to monitor avian immunity. We used the CDC EEE IgM microsphere immunoassay protocol as a framework to develop our approach and validate tests against a standard curve determined based on lab standards. We also membrane fed Aedes aegypti mosquitoes with an anti-EEE antibody to evaluate the stability of the antibody in the midgut over time and concentrations. Results: The adapted protocol was feasible but procured an inconsistent standard curve across duplicate runs. When evaluating the mosquito samples, there were contradictions among samples at each of the time points and antibody concentrations, compared to pre-determined CDC thresholds. This protocol requires future duplicate sampling and verification to increase the strength of data outcomes using mosquito bloodmeal samples. Conclusion: Current surveillance practices include conducting serology on animals, using sentinel animals to detect EEEV, or testing mosquito pools for antibody and virus prevalence. In a future study, we intend to implement the microsphere immunoassay protocol to assess Culiseta melanura samples collected from the May-October 2024 surveillance season, adjusting our antibody detection for anti-EEE IgY avian host antibodies. Adding the microsphere immunoassay to our research pipeline, the broad xeno-surveillance approach can strengthen understanding of EEEV seasonal activity and spatiotemporal immunity patterns.

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This is an Open Access Thesis.

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