Ebhodaghe Faith I, Bastos Armanda D S, Okal Michael N, Masiga Daniel K
International Centre of Insect Physiology and Ecology, Nairobi, Kenya.
Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa.
Front Vet Sci. 2022 Aug 16;9:931078. doi: 10.3389/fvets.2022.931078. eCollection 2022.
Shimba Hills is a wildlife area in Kenya and a major focus of tsetse-borne trypanosomes in East Africa. In Shimba Hills, tsetse-borne trypanosomes constrain animal health and smallholder livelihoods. However, epidemiological data to guide hotspot-targeted control of infections are limited. This study assessed the dynamics of tsetse-borne trypanosome risk in Shimba Hills with the objective to describe infection hotspots for targeted control. Tsetse flies ( = 696) collected in field surveys between November 2018 and September 2019 in Shimba Hills were characterized for chronological age and phenotypic sizes and screened for trypanosome and cattle DNA. Entomological inoculation rates for trypanosome risk assessment were derived from the product of fly abundance and molecular rates of vector infection and confirmed cattle bloodmeals in tsetse flies. In addition, cattle health indicators including anemia scores were assessed in contemporaneous parasitological surveys that screened livestock blood samples ( = 1,417) for trypanosome using the buffy-coat technique. Compared with and was the most abundant tsetse fly species in Shimba Hills and had a wider spatial distribution and greater likelihood for infectious bites on cattle. The risk of cattle infection was similar along the Shimba Hills human-wildlife-livestock interface and high within one thousand meters of the wildlife reserve boundary. Trypanosomes in tsetse flies were highly diverse and included parasites of wild-suids probably acquired from warthogs in Shimba Hills. Age and phenotypic sizes were similar between tsetse fly populations and did not affect the probability of infection or cattle bloodmeals in the vectors. Anemia was more likely in trypanosome-positive cattle whilst parasitological infection rates in cattle samples maintained a weak relationship with entomological inoculation rates probably because of the limited time scale of sample collection. Trypanosome risk in Shimba Hills is high in locations close to the wildlife reserve and driven by infectious bites on cattle. Therefore, trypanosome vector control programmes in the area should be designed to reduce abundance and tailored to target sites close to the wildlife reserve.
欣巴丘陵是肯尼亚的一个野生动物保护区，也是东非采采蝇传播锥虫的主要集中区域。在欣巴丘陵，采采蝇传播的锥虫对动物健康和小农户生计构成了限制。然而，用于指导针对感染热点地区进行控制的流行病学数据有限。本研究评估了欣巴丘陵采采蝇传播锥虫风险的动态变化，目的是描述感染热点地区以便进行有针对性的控制。在2018年11月至2019年9月期间于欣巴丘陵进行的实地调查中收集了采采蝇（ = 696只），对其按年龄顺序和表型大小进行了特征分析，并筛查了锥虫和牛的DNA。采采蝇传播锥虫风险评估的昆虫学接种率来自采采蝇数量与媒介感染分子率以及采采蝇中确认的牛血餐的乘积。此外，在同期的寄生虫学调查中评估了包括贫血评分在内的牛健康指标，该调查使用血沉棕黄层技术对家畜血液样本（ = 1417份）进行锥虫筛查。与 相比， 是欣巴丘陵数量最多的采采蝇种类，其空间分布更广，叮咬牛并导致感染的可能性更大。在欣巴丘陵的人类 - 野生动物 - 家畜交界处，牛感染的风险相似，而在距离野生动物保护区边界一千米范围内风险较高。采采蝇体内的锥虫种类高度多样，并包括可能从欣巴丘陵的疣猪身上获得的野生猪科寄生虫。采采蝇种群之间的年龄和表型大小相似，并且不影响感染概率或媒介中的牛血餐情况。锥虫检测呈阳性的牛更易出现贫血，而牛样本中的寄生虫感染率与昆虫学接种率之间的关系较弱，这可能是由于样本采集的时间范围有限。欣巴丘陵靠近野生动物保护区的地区锥虫风险较高，且由 对牛的感染性叮咬所致。因此，该地区的锥虫病媒介控制计划应旨在减少 的数量，并针对靠近野生动物保护区的目标地点进行调整。
