Department of Parasitology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
The Iranian Museum of Parasitology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Parasit Vectors. 2022 Mar 18;15(1):90. doi: 10.1186/s13071-022-05209-7.
Dirofilaria immitis and Dirofilaria repens are vector-borne zoonotic parasites which affect mainly dogs and humans worldwide. In Iran, information about the distribution of those nematodes is scant in several regions. Therefore, we investigated the prevalence of these filarial parasites in stray dogs from five Iranian provinces where no information about these parasites is available.
Blood samples were collected from 344 stray dogs in five provinces of Iran (i.e. Mazandaran, Gilan, Esfahan, Qazvin and Loresan). The presence of microfilariae was assessed using direct smear, modified Knott's test, molecular detection of filarial DNA (cox1 gene) and Wolbachia endosymbiont of parasitic nematodes (ftsZ gene) by conventional PCR (cPCR). All of the PCR products were sequenced and phylogenetic analysis was performed.
In total, 75 dogs (21.8%) were found to be positive for D. immitis by cPCR. Infection was detected in all provinces, with the highest prevalence in Gilan province (22/28; 78.6%). Acanthocheilonema reconditum was diagnosed in five dogs (1.4%) from three provinces (i.e. Esfahan, Mazandaran, Gilan). Two dogs were infected with both parasites and three were only infected with A. reconditum. Dirofilaria repens infection was not found in the examined population. Representative sequences of the D. immitis cox1 gene from dogs from the northern provinces (Mazandaran, Gilan, Qazvin) were grouped together and distinctly separate from the ones from western and central provinces (Lorestan and Esfahan), suggesting that different nematode populations are present in the country.
The data reported herein fill existing gaps in knowledge about canine filarial infection in two Iranian provinces and record the highest prevalence of D. immitis ever reported in the country (i.e. 78.6%). A geographical review of the literature about Dirofilaria spp. and A. reconditum infections in dogs and humans has also been summarized, indicating that D. immitis and D. repens are distributed in 22 of 31 provinces in Iran, whereas A. reconditum is present in fewer regions. Effective control strategies are advocated for owned dogs, and a national program for the management of stray dogs is needed to minimize the risk of infection in animals and humans.
犬恶丝虫和犬心丝虫是通过媒介传播的人畜共患寄生虫，在全球范围内主要影响狗和人类。在伊朗，这些线虫在几个地区的分布信息很少。因此，我们调查了来自伊朗五个没有这些寄生虫信息的省份的流浪狗中这些寄生虫的流行情况。
从伊朗五个省份（马赞达兰、吉兰、伊斯法罕、卡齐凡和洛雷桑）的 344 只流浪狗中采集血液样本。使用直接涂片、改良的 Knott 试验、寄生虫线虫的分子检测（cox1 基因）和沃尔巴克氏体内共生体（ftsZ 基因）的常规 PCR（cPCR）评估微丝蚴的存在。所有 PCR 产物均进行测序并进行系统发育分析。
共发现 75 只狗（21.8%）通过 cPCR 对犬恶丝虫呈阳性。在所有省份都检测到了感染，其中吉兰省的感染率最高（22/28；78.6%）。从三个省份（伊斯法罕、马赞达兰、吉兰）的五只狗（1.4%）诊断出了细颈线虫。两只狗同时感染了这两种寄生虫，三只狗仅感染了细颈线虫。在所检查的人群中未发现犬心丝虫感染。来自北部省份（马赞达兰、吉兰、卡齐凡）的犬恶丝虫 cox1 基因的代表序列聚集在一起，并与来自西部和中部省份（洛雷斯坦和伊斯法罕）的序列明显分开，表明该国存在不同的线虫种群。
本报告的数据填补了伊朗两个省份犬恶丝虫感染的知识空白，并记录了该国有史以来犬恶丝虫感染的最高流行率（即 78.6%）。还对有关狗和人类的犬恶丝虫和细颈线虫感染的文献进行了地理综述，表明犬恶丝虫和犬心丝虫分布在伊朗 31 个省份中的 22 个，而细颈线虫分布在较少的地区。建议对家养犬采取有效的控制策略，并需要制定国家流浪犬管理计划，以最大程度地降低动物和人类感染的风险。
