Xenosurveillance proof-of-principle: Detection of Toxoplasma gondii and SARS-CoV-2 antibodies in mosquito blood meals by (pan)-specific ELISAs

Using haematophagous fly blood meals to study the diversity of blood‐borne pathogens infecting wild mammals

“…This study also validates the potential of tsetse blood meal analyses (or other blood fed invertebrates) to detect the circulation of antibodies against specific pathogens in wild animals, as already suggested by previous studies (Barbazan et al, 2009 ; Cunningham et al, 1962 ; Stefanic et al, 2022 ). As a proof of concept, we tested for antibodies against African swine fever virus (ASFV) in a subset of sample pools known to contain warthog blood.…”

“…Further studies are nevertheless required to validate and develop this xeno-serosurveillance approach using tsetse, including experimental assessments to determine the probability of detection of the antibodies with respect to the age, digestion level of blood meals and host species. A recent study (Stefanic et al, 2022) indeed demonstrated differences in sensitivity in the detection of antibodies between different host species using experimentally blood fed mosquitoes and a limit of detection of 72 h postfeeding. The detection of different categories of antibodies (IgG or IgM for instance) could allow to distinguish between recent versus more ancient infections (e.g., Hsueh et al, 2004).…”

“…We also aimed to extend the approach by testing for antibodies against specific pathogens by applying serological tests to blood meals obtained from tsetse flies, as previously performed on similar or different invertebrate models (Barbazan et al, 2009;Cunningham et al, 1962;Stefanic et al, 2022). The addition of serology methods to the array of tests deployed was intended to determine which species had been exposed to a particular pathogen, so that broader surveys across wider geographic scales in the future could identify places where a pathogen species has been circulating, even though the pathogen itself cannot be ascertained through direct detection of active infections by molecular methods because outbreaks may often flare up and subside before or between surveys.…”

“…The objective of the study reported herein was to demonstrate the potential of this approach for screening a large variety of pathogens in an ecosystem with high densities of haematophagous flies and high biodiversity of vertebrates, as well as a known history of pathogen transfers between wild animals and from wild animals to humans and/or domestic animals and vice versa (e.g., Clifford et al, 2013 ). We also aimed to extend the approach by testing for antibodies against specific pathogens by applying serological tests to blood meals obtained from tsetse flies, as previously performed on similar or different invertebrate models (Barbazan et al, 2009 ; Cunningham et al, 1962 ; Stefanic et al, 2022 ). The addition of serology methods to the array of tests deployed was intended to determine which species had been exposed to a particular pathogen, so that broader surveys across wider geographic scales in the future could identify places where a pathogen species has been circulating, even though the pathogen itself cannot be ascertained through direct detection of active infections by molecular methods because outbreaks may often flare up and subside before or between surveys.…”

Fermenting molasses and a synthetic odour blend to attract blood‐fed Anopheles coluzzii

“…Since host selection plays an important role in pathogen transmission, it is critical to collect blood‐fed mosquitoes and determine their bloodmeal host. In addition, the collection of blood‐fed mosquitoes can be used for so‐called xenodiagnostics or xenomonitoring, whereby the blood meal of the mosquito can be used to detect (non‐vector borne) pathogens or their antibodies (Cameron & Ramesh, 2021; Fauver et al, 2017; Štefanić et al, 2022). The development of xenomonitoring systems with blood‐fed mosquitoes, may contribute to early warning systems for emerging infectious diseases (Cameron & Ramesh, 2021).…”