Using Zoos as Sentinels for Re-Emerging Arboviruses: Vector Surveillance during an Outbreak of Epizootic Hemorrhagic Disease at the Minnesota Zoo

Abstract

Vector-borne disease prevalence is increasing at a time when surveillance capacity in the United States is decreasing. One way to address this surveillance deficiency is to utilize established infrastructure, such as zoological parks, to investigate animal disease outbreaks and improve our epidemiological understanding of vector-borne pathogens. During fall 2020, an outbreak of epizootic hemorrhagic disease (EHD) at the Minnesota Zoo resulted in morbidity and seroconversion of several collection animals. In response to this outbreak, insect surveillance was conducted, and the collected insects were tested for the presence of epizootic hemorrhagic disease virus (EHDV) by RT-qPCR to better understand the local transmitting vector populations responsible for the outbreak. Six pools of Culicoides biting midges were positive for EHDV, including three pools of Culicoides sonorensis, two pools of Culicoides variipennis, and a pool of degraded C. variipennis complex midges. All three endemic serotypes of EHDV (1, 2, and 6) were detected in both animals and midge pools from the premises. Despite this outbreak, no EHDV cases had been reported in wild animals near the zoo. This highlights the importance and utility of using animal holding facilities, such as zoos, as sentinels to better understand the spatio-temporal dynamics of pathogen transmission.

An optical system to detect, surveil, and kill flying insect vectors of human and crop pathogens

“…For example, vector interception zones could be established around target areas supporting populations of at-risk species that are vulnerable to vector-borne diseases 220 , 221 , newly revegetated or reintroduction areas 222 , or reservoirs of vectors that negatively impact vulnerable species in nearby areas 223 – 227 . As with livestock protection, flying vector interception zones could be positioned in zoos and rearing facilities for endangered species 228 – 231 . Conversely, livestock and domestic animals harbor vector-borne diseases that can be transmitted to wildlife and native species, sometimes resulting in catastrophic consequences 232 – 234 .…”

Host Associations of Culicoides Biting Midges in Northeastern Kansas, USA

“…Culicoides sonorensis is a confirmed vector for all three North American Culicoides-borne pathogens, so this finding simply reinforces the significance of this vector within the transmission landscape. Culicoides variipennis and C. stellifer have been implicated as putative vectors for VSV and EHDV [24,31,32], and C. stellifer has further been implicated as a putative vector for BTV [32][33][34]. In the absence of laboratory transmission studies, field ecological data such as these can provide further support for the consideration of these species as putative vectors.…”