Objectives | Vector-Borne Radar

VB RADAR Objectives

Vector-Borne RADAR aims to take a One Health approach to enhance our understanding of mosquito-borne diseases of wild birds that may impact public health. Our collaborative network encompasses molecular scientists, disease ecologists, wildlife veterinarians, population ecologists, medical entomologists and citizen scientists.

Proposed VB RADAR workflow

Objective 1

Enhance surveillance for mosquito-borne viral diseases of wild birds in the UK, by increasing the scope of our pre-existing and successful surveillance network which combines government (APHA & UKHSA) with experts in birds and bird associated disease (IOZ & BTO) to compliment core government funded surveillance. This will be achieved through increased avian and mosquito submissions for flavivirus screening from areas in the UK deemed at higher risk of emerging viral incursion, by engaging with and co-opting bird observatories and bird ringers to collect samples. We will also enhance surveillance through promotion of wider collaboration with additional stakeholders to raise awareness of diseases in birds and promote specimen submission for testing (e.g. wildlife rehabilitators, zoological collections).

Sampling for VB RADAR, green areas are higher risk of WNV incursion (map courtesy of Bessel et al. 2014.)

Objective 2

Develop an early warning system for the detection of potentially zoonotic viral disease outbreaks in wild bird populations by co-opting and integrating established citizen science schemes for disease surveillance and bird monitoring schemes. A workflow will be created that can identify clusters of disease incident reports of sentinel species, and conduct syndromic surveillance (e.g. neurological signs), through the Garden Wildlife Health project, combined with reductions in weekly reporting rates collected by BTO Garden BirdWatch participants. These independent, yet complementary schemes, generate data in near real-time that have been shown to be valuable in retrospect in identifying patterns of blackbird mortality and disease-mediated population decline caused by Usutu virus (USUV) in the UK in 2020.

Blackbird disease incident reports in 2020, showing a cluster around USUV index site. Image courtesy of Lawson et al. 2022

Objective 3

Detect novel mosquito-borne viral disease incursion and incipient transmission pathways by sampling live migrant birds and geographically associated mosquito populations, combined with sequence characterisation. This will include assessing mosquito community diversity and population densities, which may identify exotic mosquito vectors not native to the UK, at key bird land-fall sites and ringing stations. This will inform our understanding of the role of local vector species in disease transmission, which in turn will guide disease mitigation and vector control strategies. We will record annual infection and exposure status for a subset of migrant and resident birds in the South East of England, which are sampled throughout the mosquito active season to identify potential incursion and transmission routes and at-risk populations.

Immunohistochemical analysis of USUV infected blackbird. Image courtesy of Folly et al. 2022

Objective 4

Quantify seasonal variation in blackbird demography and habitat use by coordinating citizen scientists (BTO) to ring birds at sentinel sites (with concurrent mosquito sampling) and engage with a wider citizen science network to monitor seasonal variation in the use of gardens by adult and juvenile blackbirds. These findings will greatly inform our understanding of how USUV emergence in the UK is impacting this highly susceptible species.

Eurasian blackbird (Turdus merula). Photo credit Rob Robinson 2022.