Yancey C B, Diniz P P V P, Breitschwerdt E B, Hegarty B C, Wiesen C, Qurollo B A
Department of Clinical Sciences and the Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, 27607, USA.
Western University of Health Sciences, College of Veterinary Medicine, Pomona, California, 91766, USA.
J Small Anim Pract. 2018 May;59(5):286-293. doi: 10.1111/jsap.12799. Epub 2017 Dec 27.
To evaluate doxycycline treatment efficacy and post-treatment pathogen persistence in dogs naturally infected with Anaplasma phagocytophilum in endemic regions of the USA.
Symptomatic dogs in four US states (MN, WI, CT and CA) were evaluated before treatment with doxycycline and approximately 30 and 60 days post-treatment. Clinicopathological parameters, co-exposures and A. phagocytophilum DNA in whole blood and lymph node samples were compared between A. phagocytophilum infected and uninfected dogs.
In total, 42 dogs fulfilled the inclusion criteria, with 16 dogs (38%) blood PCR-positive and 26 dogs (62%) blood PCR-negative for A. phagocytophilum. At initial evaluation, the proportion of clinicopathological abnormalities was similar between A. phagocytophilum infected and uninfected dogs, although thrombocytopenia and lymphopenia were statistically more prevalent among A. phagocytophilum infected dogs. Treatment with doxycycline resulted in resolution of all clinical abnormalities in infected dogs; four dogs had persistent haematological abnormalities, including mild leukopenia, eosinopenia and lymphopenia. All 16 infected dogs became blood PCR-negative approximately 30 and 60 days after treatment onset. Additionally, 13/13 (100%) lymph node specimens tested post-treatment were PCR-negative. Select clinicopathological abnormalities persisted in uninfected dogs after treatment.
The results of this study support the efficacy of doxycycline therapy for clinical treatment of dogs naturally infected with A. phagocytophilum in the USA. This study did not find clinical, haematological or microbiological indicators that supported the persistence of A. phagocytophilum infection in naturally infected dogs following treatment with doxycycline for 28 days.
评估强力霉素在美国地方性流行区域对自然感染嗜吞噬细胞无形体犬只的治疗效果及治疗后病原体的持续存在情况。
对美国四个州（明尼苏达州、威斯康星州、康涅狄格州和加利福尼亚州）有症状的犬只在使用强力霉素治疗前以及治疗后约30天和60天进行评估。比较嗜吞噬细胞无形体感染犬和未感染犬的临床病理参数、共同暴露情况以及全血和淋巴结样本中的嗜吞噬细胞无形体DNA。
共有42只犬符合纳入标准，其中16只犬（38%）血液PCR检测呈嗜吞噬细胞无形体阳性，26只犬（62%）血液PCR检测呈阴性。在初始评估时，嗜吞噬细胞无形体感染犬和未感染犬的临床病理异常比例相似，尽管血小板减少症和淋巴细胞减少症在嗜吞噬细胞无形体感染犬中在统计学上更为普遍。强力霉素治疗使感染犬的所有临床异常症状得到缓解；四只犬存在持续性血液学异常，包括轻度白细胞减少、嗜酸性粒细胞减少和淋巴细胞减少。所有16只感染犬在治疗开始后约30天和60天血液PCR检测均转为阴性。此外，治疗后检测的13/13（100%）份淋巴结标本PCR检测呈阴性。治疗后未感染犬仍存在某些临床病理异常。
本研究结果支持强力霉素疗法对美国自然感染嗜吞噬细胞无形体犬只的临床治疗效果。本研究未发现支持强力霉素治疗28天后自然感染犬中嗜吞噬细胞无形体感染持续存在的临床、血液学或微生物学指标。
