Primate-Targeted Xenosurveillance: A Non-invasive Tool for Health Monitoring


Gauthier RAWAY1 (gauthier.raway@uliege.be), Hugo NICAISE1, Sena ADI SUBRATA2, Mutien-Marie GARIGLIANY3, Fany BROTCORNE1


1 Research Unit SPHERES, Université de Liège, Liège, Belgium ; 2 Faculty of Forestry, Universitas Gadjah Mada, Yogyakarta, Indonesia ; 3 Institut des Epidémies (INDEEP), Université de Liège, Liège, Belgium


Introduction and objectives

Infectious diseases in non-human primates warrant considerable attention for global health. However, wildlife infection surveillance is often constrained by logistical and ethical challenges associated with biological sampling. An innovative and non-invasive technique for monitoring the health status of primates is the use of mosquitoes as "flying syringes": Xenosurveillance.

Our aim is to assess the reliability of mosquito bloodmeal analyses as a tool for obtaining blood samples from wild primates. Here, we showcase an optimized approach to screen free-ranging Balinese macaques (Macaca fascicularis) for Orthoflavivirus infections.

Methods

Our xenosurveillance pipeline comprises three main steps: (1) capture of blood-fed mosquitoes; (2) DNA barcoding to identify the vertebrate hosts of bloodmeals; (3) serological screening of primate blood samples for Orthoflavivirus IgG.

Results

A pilot session conducted from April to June 2025 yielded 68 bloodmeals from diverse hosts (e.g. cattle, humans, wild deer). A second session (July 2025) conducted in an area densely populated by macaques yielded 7 macaque-derived bloodmeals out of 21 collected. Macaque samples and 7 human samples from the same area were screened using adapted ELISAs. All macaque and five human samples tested positive for Orthoflavivirus IgG.

Discussion and conclusion

Although preliminary, these findings suggest high Orthoflavivirus infection rates at the human-primate interface in Bali, and highlight the potential of xenosurveillance for monitoring primate populations at scale. We identified the need to sample in areas of sustained macaque activity, inlcluding appropriate vertical strata. Ongoing work focuses on developing additional serological assays to discriminate IgG beyond the genus level.


Keywords: Cutting-edge technologies for primate research, Xenosurveillance, Orthoflavivirus, bloodmeal, Macaca fascicularis.