Xenosurveillance: A Novel Mosquito-Based Approach for Examining the Human-Pathogen Landscape

Abstract

BackgroundGlobally, regions at the highest risk for emerging infectious diseases are often the ones with the fewest resources. As a result, implementing sustainable infectious disease surveillance systems in these regions is challenging. The cost of these programs and difficulties associated with collecting, storing and transporting relevant samples have hindered them in the regions where they are most needed. Therefore, we tested the sensitivity and feasibility of a novel surveillance technique called xenosurveillance. This approach utilizes the host feeding preferences and behaviors of Anopheles gambiae, which are highly anthropophilic and rest indoors after feeding, to sample viruses in human beings. We hypothesized that mosquito bloodmeals could be used to detect vertebrate viral pathogens within realistic field collection timeframes and clinically relevant concentrations.Methodology/Principal FindingsTo validate this approach, we examined variables influencing virus detection such as the duration between mosquito blood feeding and mosquito processing, the pathogen nucleic acid stability in the mosquito gut and the pathogen load present in the host’s blood at the time of bloodmeal ingestion using our laboratory model. Our findings revealed that viral nucleic acids, at clinically relevant concentrations, could be detected from engorged mosquitoes for up to 24 hours post feeding by qRT-PCR. Subsequently, we tested this approach in the field by examining blood from engorged mosquitoes from two field sites in Liberia. Using next-generation sequencing and PCR we were able to detect the genetic signatures of multiple viral pathogens including Epstein-Barr virus and canine distemper virus.Conclusions/SignificanceTogether, these data demonstrate the feasibility of xenosurveillance and in doing so validated a simple and non-invasive surveillance tool that could be used to complement current biosurveillance efforts.

Feasibility of Using the Mosquito Blood Meal for Rapid and Efficient Human and Animal Virus Surveillance and Discovery

“…11,[15][16][17][18] Ingredients on FTA cards inactivate potential biohazardous components in the sample †Water was used instead of nucleic acids to detect background contamination from the process in laboratory.…”

“…6,7 However, captured blood-fed mosquitoes are not typically assayed for non-mosquito-vectored pathogens, even though their blood meals may contain a useful source of blood for the detection of pathogens in humans and animals. [8][9][10][11] The practice of using blood-fed mosquitoes to conduct surveillance for human and livestock viral pathogens has been termed xenosurveillance. 11 This study explored the pathogen nucleic acid sequence stability in host blood after mosquito ingestion to determine if blood-fed female mosquitoes could be used as a source for virus/pathogen surveillance and discovery and ultimately a surveillance tool.…”

“…[8][9][10][11] The practice of using blood-fed mosquitoes to conduct surveillance for human and livestock viral pathogens has been termed xenosurveillance. 11 This study explored the pathogen nucleic acid sequence stability in host blood after mosquito ingestion to determine if blood-fed female mosquitoes could be used as a source for virus/pathogen surveillance and discovery and ultimately a surveillance tool. Specifically, the study explored viral stability in the mosquito gut, the time interval that a nonreplicating virus can be detected in the mosquito after blood feeding, and the efficiency of recovering viral RNA.…”

Viral Metagenomics on Blood-Feeding Arthropods as a Tool for Human Disease Surveillance

“…Xenosurveillance and vector-enabled metagenomics (VEM) are surveillance approaches that can exploit mosquitoes to capture the viral diversity of the animal, human or plant host the mosquito has fed on (Figure 1). Xenosurveillance, a term introduced by Brackney et al, refers to the identification of viral pathogens from total nucleic acids extracted from mosquito blood meals, either by next-generation sequencing (NGS) or conventional PCR assays [9]. Recent developments in NGS and viral metagenomics, which is the shotgun sequencing of viral nucleic acids extracted from purified virus particles, offer great opportunities for the characterization of the complete viral diversity in an organism or a population [10].…”

“…In a second feasibility study to use mosquito blood meals for virus detection with a novel approach called xenosurveillance, Grubaugh and others developed a laboratory model to explore variables influencing detection of human immunodeficiency virus 1, West Nile virus, Pirital virus, Lassa virus and Chikungunya virus in blood-fed Anopheles gambiae mosquitoes [9]. The pathogen load and the stability of viral nucleic acids present in the mosquitoes’ blood meals were determined at different time points after blood feeding by qRT-PCR and NGS.…”