Wildlife Research and Training Institute, Naivasha, Kenya.
International Livestock Research Institute, Nairobi, Kenya.
PLoS Negl Trop Dis. 2022 Aug 8;16(8):e0010596. doi: 10.1371/journal.pntd.0010596. eCollection 2022 Aug.
Co-infection, especially with pathogens of dissimilar genetic makeup, may result in a more devastating impact on the host. Investigations on co-infection with neglected zoonotic pathogens in wildlife are necessary to inform appropriate prevention and control strategies to reduce disease burden in wildlife and the potential transmission of these pathogens between wildlife, livestock and humans. This study assessed co-exposure of various Kenyan wildflife species with Brucella spp, Coxiella burnetii and Rift Valley fever virus (RVFV).
A total of 363 sera from 16 different wildlife species, most of them (92.6%) herbivores, were analysed by Enzyme-linked immunosorbent assay (ELISA) for IgG antibodies against Brucella spp, C. burnetii and RVFV. Further, 280 of these were tested by PCR to identify Brucella species.
Of the 16 wildlife species tested, 15 (93.8%) were seropositive for at least one of the pathogens. Mean seropositivities were 18.9% (95% CI: 15.0-23.3) for RVFV, 13.7% (95% CI: 10.3-17.7) for Brucella spp and 9.1% (95% CI: 6.3-12.5) for C. burnetii. Buffaloes (n = 269) had higher seropositivity for Brucella spp. (17.1%, 95% CI: 13.0-21.7%) and RVFV (23.4%, 95% CI: 18.6-28.6%), while giraffes (n = 36) had the highest seropositivity for C. burnetii (44.4%, 95% CI: 27.9-61.9%). Importantly, 23 of the 93 (24.7%) animals positive for at least one pathogen were co-exposed, with 25.4% (18/71) of the positive buffaloes positive for brucellosis and RVFV. On molecular analysis, Brucella DNA was detected in 46 (19.5%, CI: 14.9-24.7) samples, with 4 (8.6%, 95% CI: 2.2-15.8) being identified as B. melitensis. The Fisher's Exact test indicated that seropositivity varied significantly within the different animal families, with Brucella (p = 0.013), C. burnetii (p = <0.001) and RVFV (p = 0.007). Location was also significantly associated (p = <0.001) with Brucella spp. and C. burnetii seropositivities.
Of ~20% of Kenyan wildlife that are seropositive for Brucella spp, C. burnetii and RVFV, almost 25% indicate co-infections with the three pathogens, particularly with Brucella spp and RVFV.
合并感染，特别是具有不同遗传背景的病原体的合并感染，可能对宿主造成更严重的影响。有必要对野生动物中被忽视的人畜共患病病原体的合并感染进行调查，以便为减少野生动物中的疾病负担以及这些病原体在野生动物、牲畜和人类之间的潜在传播提供适当的预防和控制策略。本研究评估了肯尼亚各种野生动物物种与布鲁氏菌、柯克斯体和裂谷热病毒（RVFV）的合并暴露情况。
共分析了来自 16 种不同野生动物物种的 363 份血清，其中大多数（92.6%）为食草动物，通过酶联免疫吸附试验（ELISA）检测 IgG 抗体对布鲁氏菌、柯克斯体和 RVFV 的抗体。此外，其中 280 份用 PCR 进行了检测，以鉴定布鲁氏菌种。
在测试的 16 种野生动物物种中，有 15 种（93.8%）至少有一种病原体呈血清阳性。RVFV 的平均血清阳性率为 18.9%（95%CI：15.0-23.3），布鲁氏菌属为 13.7%（95%CI：10.3-17.7），柯克斯体为 9.1%（95%CI：6.3-12.5）。水牛（n=269）对布鲁氏菌属（17.1%，95%CI：13.0-21.7%）和 RVFV（23.4%，95%CI：18.6-28.6%）的血清阳性率更高，而长颈鹿（n=36）对柯克斯体的血清阳性率最高（44.4%，95%CI：27.9-61.9%）。重要的是，在至少一种病原体呈阳性的 93 只动物中有 23 只呈合并暴露，其中 25.4%（18/71）的阳性水牛同时感染了布鲁氏菌病和 RVFV。在分子分析中，在 46 份（19.5%，CI：14.9-24.7）样本中检测到布鲁氏菌 DNA，其中 4 份（8.6%，95%CI：2.2-15.8）被鉴定为 B. melitensis。Fisher 精确检验表明，不同动物科之间的血清阳性率存在显著差异，布鲁氏菌（p=0.013）、柯克斯体（p<0.001）和 RVFV（p=0.007）。位置也与布鲁氏菌属和柯克斯体的血清阳性率显著相关（p<0.001）。
在肯尼亚约 20%的血清呈布鲁氏菌属、柯克斯体和 RVFV 阳性的野生动物中，近 25%的野生动物同时感染了这三种病原体，尤其是布鲁氏菌属和 RVFV。
