Assessing the feasibility of fly based surveillance of wildlife infectious diseases

Abstract

Monitoring wildlife infectious agents requires acquiring samples suitable for analyses, which is often logistically demanding. A possible alternative to invasive or non-invasive sampling of wild-living vertebrates is the use of vertebrate material contained in invertebrates feeding on them, their feces, or their remains. Carrion flies have been shown to contain vertebrate DNA; here we investigate whether they might also be suitable for wildlife pathogen detection. We collected 498 flies in Taï National Park, Côte d’Ivoire, a tropical rainforest and examined them for adenoviruses (family Adenoviridae), whose DNA is frequently shed in feces of local mammals. Adenoviral DNA was detected in 6/142 mammal-positive flies. Phylogenetic analyses revealed that five of these sequences were closely related to sequences obtained from local non-human primates, while the sixth sequence was closely related to a murine adenovirus. Next-generation sequencing-based DNA-profiling of the meals of the respective flies identified putative hosts that were a good fit to those suggested by adenoviral sequence affinities. We conclude that, while characterizing the genetic diversity of wildlife infectious agents through fly-based monitoring may not be cost-efficient, this method could probably be used to detect the genetic material of wildlife infectious agents causing wildlife mass mortality in pristine areas.

Blood meal analysis of tsetse flies (Glossina pallidipes: Glossinidae) reveals higher host fidelity on wild compared with domestic hosts

“…We took a conservative approach to host identification by basing analyses only on the dominant host species identified in each fly, but this could represent either the most recent blood meal or the hosts on which most efficient feeding occurred. There has been a recent shift towards using next generation sequencing approaches for amplicon based host identification (Hoffmann et al . 2016; Reeves et al .…”

“…Although this approach has typically focused on vectors of particular pathogens, it has also been proposed that blood-sucking flies that do not themselves transmit the focal parasites could be used as “flying syringes” to investigate blood-borne pathogen diversity (Bitome-Essono et al . 2017; Hoffmann et al . 2016).…”

Female Blow Flies As Vertebrate Resource Indicators

“…Overall, blow flies contain vast reservoirs of environmental information waiting to be tapped by scientists. Additional ecological data can also be extracted from flies, such as population genetics of targeted species 12 , vertebrate-pathogen associations 35,36 , and even angiosperm diversity in phenological studies (wild blow flies consume nectar 37,38 and potentially pollen) 39 . Furthermore, flies can be used to monitor environmental pollution (e.g.…”

Incorporating genomic methods into contact networks to reveal new insights into animal behaviour and infectious disease dynamics

“…Within the scope of wildlife studies, genomic tools may also provide important opportunities to maximize the use of non-invasive sampling techniques. Non-invasive techniques are expanding in their range and utility, and may be particularly important for studying populations of endangered or at-risk species, where capture and handling of individuals carries increased risk to overall population health (de Carvalho Ferreira et al, 2014; Hoffmann et al, 2016; Smiley Evans et al, 2016).…”