Eastern equine encephalitis virus (EEEV; alphavirus) and West Nile virus (WNV; flavivirus) are mosquito-borne pathogens maintained in enzootic cycles in bird populations by mosquitoes that feed primarily on birds. EEEV and WNV can infect horses and humans when populations of infectious bridge mosquito vectors (blood feed on both birds and mammals) become involved in the epidemic cycle. EEEV causes brain swelling (encephalitis) and subsequent death in infected horses and emus. WNV can cause neuroinvasive issues, death, or result in long-term health issues in veterinary cases. The health impacts of EEEV infection in humans can be deadly or debilitating with long term sequelae. WNV can cause non neuroinvasive (asymptomatic to mild systematic symptoms) or neuroinvasive (long term health issues to death) issues in humans. Although there is a horse vaccine for both EEEV and WNV, horse owners are not always compliant in vaccinating animals. As of August 2018, there have already been six EEEV-positive horse cases in unvaccinated horses at farms in North Carolina (NC). Through state-level databases, we will analyze WNV and EEEV incidence in mosquito pools, humans, and veterinary cases (e.g., horses, emus) for the past decade (2008-2018) in NC. We will analyze onset dates with respect to rainfall and temperature to determine the presence of predictive relationships, if any. Since humans can also be infected with EEEV and WNV, outdoor workers at horse farms and others participating in outdoor activities near horses/emus may be at risk during epidemic/outbreak periods. Hence, we propose to survey horse owners/farmers in NC regarding horse vaccination practices, exposure to mosquito bites, and knowledge/concern about mosquito-borne diseases. We will collect data on arbovirus notification protocols and local mosquito control practices that may occur in response to different types of disease cases. We expect the findings from the proposed study to assess current risk and control measures in place for public health pests and educate farmers and others that interact with horses/emus on potential methods for exposure prevention.
