Payne Ariane, Ruette Sandrine, Jacquier Mickaël, Richomme Céline, Lesellier Sandrine, Middleton Sonya, Duhayer Jeanne, Rossi Sophie
Wildlife Disease Unit, French Office for Biodiversity, Orléans, France.
Groupement de Défense Sanitaire de Côte d'Or, Breteniere, France.
Front Vet Sci. 2022 Mar 9;9:787932. doi: 10.3389/fvets.2022.787932. eCollection 2022.
Although France is officially declared free of bovine tuberculosis (TB), infection is still observed in several regions in cattle and wildlife, including badgers (). In this context, vaccinating badgers should be considered as a promising strategy for the reduction in transmission between badgers and other species, and cattle in particular. An oral vaccine consisting of live Bacille Calmette-Guérin (BCG) contained in bait is currently under assessment for badgers, for which testing bait deployment in the field and assessing bait uptake by badgers are required. This study aimed to evaluate the bait uptake by badgers and determine the main factors influencing uptake in a TB-infected area in Burgundy, north-eastern France. The baits were delivered at 15 different setts located in the vicinity of 13 pastures within a TB-infected area, which has been subject to intense badger culling over the last decade. Pre-baits followed by baits containing a biomarker (Rhodamine B; no BCG vaccine) were delivered down sett entrances in the spring (8 days of pre-baiting and 4 days of baiting) and summer (2 days of pre-baiting and 2 days of baiting) of 2018. The consumption of the marked baits was assessed by detecting fluorescence, produced by Rhodamine B, in hair collected in hair traps positioned at the setts and on the margins of the targeted pastures. Collected hairs were also genotyped to differentiate individuals using 24 microsatellites markers and one sex marker. Bait uptake was estimated as the proportion of badgers consuming baits marked by the biomarker over all the sampled animals (individual level), per badger social group, and per targeted pasture. We found a bait uptake of 52.4% (43 marked individuals of 82 genetically identified) at the individual level and a mean of 48.9 and 50.6% at the social group and pasture levels, respectively. The bait uptake was positively associated with the presence of cubs (social group level) and negatively influenced by the intensity of previous trapping (social group and pasture levels). This study is the first conducted in France on bait deployment in a badger population of intermediate density after several years of intensive culling. The results are expected to provide valuable information toward a realistic deployment of oral vaccine baits to control TB in badger populations.
尽管法国官方宣布已消灭牛结核病（TB），但在包括獾在内的牛和野生动物的几个地区仍观察到感染情况（）。在这种情况下，给獾接种疫苗应被视为减少獾与其他物种，特别是牛之间传播的一种有前景的策略。一种由含活卡介苗（BCG）的诱饵组成的口服疫苗目前正在对獾进行评估，为此需要在野外测试诱饵投放情况并评估獾对诱饵的摄取情况。本研究旨在评估法国东北部勃艮第一个结核病感染地区獾对诱饵的摄取情况，并确定影响摄取的主要因素。诱饵被投放在结核病感染地区13个牧场附近的15个不同洞穴，该地区在过去十年中一直进行着密集的獾捕杀。在2018年春季（8天预投放和4天投放）和夏季（2天预投放和2天投放），先投放预诱饵，然后在洞穴入口处投放含有生物标志物（罗丹明B；无卡介苗疫苗）的诱饵。通过检测位于洞穴和目标牧场边缘的毛发陷阱中收集的毛发中罗丹明B产生的荧光来评估标记诱饵的消耗情况。收集的毛发还使用24个微卫星标记和一个性别标记进行基因分型以区分个体。诱饵摄取量估计为食用生物标志物标记诱饵的獾在所有采样动物（个体水平）、每个獾社会群体和每个目标牧场中所占的比例。我们发现在个体水平上诱饵摄取率为52.4%（82只经基因鉴定的个体中有43只被标记），在社会群体和牧场水平上平均分别为48.9%和50.6%。诱饵摄取与幼崽的存在（社会群体水平）呈正相关，并受到先前诱捕强度（社会群体和牧场水平）的负面影响。这项研究是法国在经过数年密集捕杀后，首次对中等密度獾种群进行诱饵投放的研究。预期结果将为实际部署口服疫苗诱饵以控制獾群中的结核病提供有价值的信息。
