Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Buenteweg 17, 30559, Hannover, Germany.
Laboratorio de Parasitología, Escuela de Medicina Veterinaria, Universidad Nacional, Campus Benjamín Núñez, Heredia, Costa Rica.
Parasit Vectors. 2018 Nov 12;11(1):585. doi: 10.1186/s13071-018-3173-1.
Vector-borne diseases constitute a major problem for veterinary and public health, especially in tropical regions like Central America. Domestic dogs may be infected with several vector-borne pathogens of zoonotic relevance, which may also severely compromise canine health.
To assess the prevalence of canine vector-borne diseases in Nicaragua, 329 dogs from seven cities, which were presented to the veterinarian for various reasons, were included in this study. Dogs were examined clinically and diagnostic blood samples were taken for analysis of packed cell volume (PCV) and presence of microfilariae as well as antigen of Dirofilaria immitis and antibodies to Ehrlichia spp., Anaplasma spp. and Borrelia burgdorferi (sensu lato) by use of a commercially available rapid ELISA. To detect current infections, specific PCRs for the detection of E. canis, A. platys and A. phagocytophilum were carried out on blood samples of the respective seropositive dogs. Microfilaremic blood samples, as well as D. immitis antigen positive samples were further subjected to PCR and subsequent sequencing for filarial species identification.
Antibodies against Ehrlichia spp. were present in 62.9% of dogs, while Anaplasma spp. seroprevalence was 28.6%. Antibodies against species of both genera were detected in 24.9% of dogs. Borrelia burgdorferi (s.l.) antibodies were not detected. Dirofilaria immitis antigen was present in six animals (1.8%), two of which also showed D. immitis microfilariae in buffy coat. In addition to D. immitis, Acanthocheilonema reconditum was identified by PCR and sequencing in two of four additional microfilaremic blood samples, which were tested negative for D. immitis antigen. Current E. canis infections as defined by DNA detection were present in 58.5% of Ehrlichia-seropositive dogs, while 5.3% of Anaplasma-seropositive dogs were PCR-positive for A. platys, 2.2% for A. phagocytophilum and 16.0% for both Anaplasma species. Current E. canis infection had a statistically significant negative impact on PCV, whereas no relationship between infection status and clinical signs of disease could be observed.
These results indicate that canine vector-borne diseases are widespread in Nicaragua and that dogs may constitute a reservoir for human infection with E. canis, A. phagocytophilum and D. immitis. Thus, the use of repellents or acaricides to protect dogs from vector-borne diseases is strongly recommended.
虫媒病是兽医和公共卫生的一个主要问题，尤其是在中美洲等热带地区。 家养犬可能感染多种具有动物源性的虫媒病原体，这也可能严重损害犬的健康。
为评估尼加拉瓜犬类虫媒病的流行情况，对来自七个城市的 329 只因各种原因就诊兽医的犬进行了研究。对犬进行临床检查，并采集诊断性血液样本，以分析红细胞压积（PCV）和微丝蚴的存在情况，以及使用商业上可用的快速 ELISA 检测犬恶丝虫抗原、埃立克体属、无形体属和伯氏疏螺旋体（广义）的抗体。为检测当前感染情况，对各自血清阳性犬的血液样本进行了检测犬埃立克体、犬无形体和犬嗜吞噬细胞无形体的特异性 PCR。对微丝蚴血症样本以及犬恶丝虫抗原阳性样本进一步进行 PCR 和后续测序，以鉴定丝虫种类。
62.9%的犬存在埃立克体属抗体，28.6%的犬存在无形体属血清阳性。24.9%的犬同时存在这两个属的抗体。未检测到伯氏疏螺旋体（s.l.）抗体。犬恶丝虫抗原存在于 6 只动物（1.8%）中，其中 2 只在血涂片上也有犬恶丝虫微丝蚴。除犬恶丝虫外，还通过 PCR 和测序在另外 4 份微丝蚴血症血液样本中鉴定出了细颈线虫属，这 4 份样本对犬恶丝虫抗原检测均为阴性。根据 DNA 检测确定的当前犬埃立克体感染在埃立克体属血清阳性犬中的阳性率为 58.5%，而在无形体属血清阳性犬中，犬无形体的 PCR 阳性率为 5.3%，犬嗜吞噬细胞无形体为 2.2%，两种无形体均为 16.0%。当前犬埃立克体感染对 PCV 有统计学显著的负面影响，而未观察到感染状态与疾病临床体征之间的关系。
这些结果表明，尼加拉瓜犬类虫媒病广泛流行，犬可能是人类感染犬埃立克体、犬嗜吞噬细胞无形体和犬恶丝虫的储存宿主。因此，强烈建议使用驱虫剂或杀蜱剂来保护犬免受虫媒病的侵害。
