Molecular Diagnostic Unit, Diagnostic Laboratories, Bristol Veterinary School and Langford Vets, University of Bristol, Langford, UK.
Department of Pathobiology and Population Sciences, The Royal Veterinary College, University of London, Hatfield, Hertfordshire, UK.
BMC Vet Res. 2019 Sep 18;15(1):331. doi: 10.1186/s12917-019-2083-6.
Dogs that have clinical leishmaniosis (ClinL), caused by the parasite Leishmania infantum, are commonly co-infected with other pathogens, especially vector-borne pathogens (VBP). A recent PCR-based study found that ClinL dogs are more likely to be additionally infected with the rickettsial bacteria Ehrlichia canis. Further information on co-infections in ClinL cases with VBP, as assessed by serology, is required. The research described in this report determined if dogs with ClinL are at higher risk of exposure to VBP than healthy control dogs using a case-control serology study.
Of the 47 dogs with ClinL, anti-E. canis/ Ehrlichia ewingii antibodies were detected in 17 (36.2%), anti-Anaplasma phagocytophilum/Anaplasma platys antibodies in 5 (10.6%) and antigen for Dirofilaria immitis in 2 (4.3%). Of the 87 control dogs, anti-E. canis/E. ewingii antibodies were detected in 14 (16.1%) and anti-A. phagocytophilum/A. platys antibodies in 2 (2.3%). No anti-Borrelia burgdorferi antibody tests were positive. No statistical differences between the ClinL dogs and control dogs regarding lifestyle or use of ectoparasitic prevention, were identified. The ClinL was significantly associated with anti-E. canis/E. ewingii antibodies (odds ratio = 2.9, 95% confidence interval: 1.3-6.7, P = 0.010) compared to controls by both multivariable logistic regression and structural equation modelling.
It was demonstrated that an increased risk for E. canis/E. ewingii seropositivity is present in dogs with ClinL compared to clinically healthy control dogs, despite similar ectoparasitic prevention use and lifestyle. Based on these findings it is suggested that dogs with ClinL should not only be tested for E. canis co-infection using PCR but also serologically for E. canis/E. ewingii.
患有由寄生虫利什曼原虫引起的临床利什曼病（ClinL）的狗通常会同时感染其他病原体，特别是媒介传播的病原体（VBP）。最近一项基于 PCR 的研究发现，ClinL 狗更有可能另外感染立克次体细菌埃立克体犬种。需要通过血清学评估来进一步了解 ClinL 病例中与 VBP 的合并感染情况。本报告中描述的研究使用病例对照血清学研究来确定 ClinL 狗是否比健康对照狗面临更高的 VBP 暴露风险。
在 47 只 ClinL 犬中，17 只（36.2%）检测到抗埃立克体犬种/埃立希体 ewingii 抗体，5 只（10.6%）检测到抗嗜吞噬细胞无形体/平体无形体抗体，2 只（4.3%）检测到抗原迪氏丝虫。在 87 只对照犬中，14 只（16.1%）检测到抗埃立克体犬种/埃立希体 ewingii 抗体，2 只（2.3%）检测到抗嗜吞噬细胞无形体/平体无形体抗体。没有检测到抗伯氏疏螺旋体抗体阳性。在生活方式或使用外寄生虫预防方面，ClinL 犬与对照犬之间没有发现统计学差异。通过多变量逻辑回归和结构方程模型，ClinL 与抗埃立克体犬种/埃立希体 ewingii 抗体呈显著相关（优势比=2.9，95%置信区间：1.3-6.7，P=0.010）。
与临床健康对照犬相比，ClinL 犬的埃立克体犬种/埃立希体 ewingii 血清阳性率增加，尽管使用了类似的外寄生虫预防措施和生活方式。基于这些发现，建议不仅对 ClinL 犬进行 PCR 检测以确定是否存在埃立克体犬种合并感染，还应通过血清学方法检测埃立克体犬种/埃立希体 ewingii 抗体。
