Department of Biosciences, COMSATS University Islamabad (CUI), Park Road, Chakh Shahzad, Islamabad, Pakistan.
Department of Biosciences, COMSATS University Islamabad (CUI), Park Road, Chakh Shahzad, Islamabad, Pakistan.
Acta Trop. 2020 Sep;209:105559. doi: 10.1016/j.actatropica.2020.105559. Epub 2020 May 29.
Cystic echinococcosis (CE) is a zoonotic parasitic disease that can result in human and animal health problems globally. Although the disease is known to be endemic in Asia and the Middle East, there are few epidemiological studies on CE in Pakistan. The purpose of the present study was to identify the Echinococcus granulosus sensu lato species and genotypes contributing to human CE cases in the Khyber Pakhtunkhwa (KPK) province of Pakistan. A total of fifty-six formalin fixed paraffin embedded (FFPE) CE cyst samples of human origin were collected from the Pathology Department, Rehman Medical Institute (RMI), KPK for the years 2012-2017. Cyst samples came from the liver (26/56; 46.4%), lungs (3/56; 5.3%), spleen (3/56; 5.3%), pelvis (1/56; 1.8%), breast (1/56; 1.8%), and thigh (1/56; 1.8%). The organ location for 21 of the cysts was not recorded. World Health Organization-Informal Working Group on Echinococcosis (WHO-IWGE) ultrasound-based cyst staging was available for 17 of the 26 (65.4%) hepatic cysts. Five of these cysts (29.4%) were CE3 (transitional), nine (52.9%) were CE4 (inactive), and three (17.6%) were CE5 (inactive). Most of the cysts were obtained from CE patients that were ethnically Afghan Pashtuns (44/56; 78.6%), while 12.5% (7/56) were from patients that were Pakistani Pashtuns. The majority (41/56; 73.2%) of patients reported having close interactions with dogs. Using 12SrRNA primers, 33 cyst samples were identified as being caused by E. granulosus sensu stricto (s.s.). Mitochondrially encoded cytochrome C oxidase 1 (mt-CO1) was evaluated for the remaining 23 samples. PCR product was obtained from six of these 23 samples. Of these six samples, one was identified as Echinococcus canadensis (G6/7). Haplotype analysis showed high haplotype and low nucleotide diversity for the mt-CO1 gene. There were 26 polymorphic sites for the mt-CO1 sequence, of which 65.3% (17/26) were parsimony informative. The E. canadensis mt-CO1 haplotype network consisted of 11 haplotypes, with a main central haplotype. In conclusion, it appears that E. granulosus s.s. and E. canadensis (G6/7) are circulating in the northwestern region of Pakistan. Further molecular epidemiological studies are needed to explore the local genetic diversity of the parasite.
包虫病（CE）是一种人畜共患的寄生虫病，可导致全球人类和动物健康问题。尽管这种疾病在亚洲和中东已知是地方性的，但在巴基斯坦，对 CE 的流行病学研究很少。本研究的目的是确定导致巴基斯坦开伯尔-普赫图赫瓦省（KPK）人类 CE 病例的细粒棘球绦虫亚种和基因型。从 2012 年至 2017 年，从 KPK 的雷曼医学研究所（RMI）病理学系共收集了 56 例来自人类的福尔马林固定石蜡包埋（FFPE）CE 囊肿样本。囊肿样本来自肝脏（26/56；46.4%）、肺（3/56；5.3%）、脾（3/56；5.3%）、骨盆（1/56；1.8%）、乳房（1/56；1.8%）和大腿（1/56；1.8%）。21 个囊肿的器官位置未记录。世界卫生组织非正式棘球蚴病工作组（WHO-IWGE）的基于超声的囊肿分期可用于 26 个肝囊肿中的 17 个（65.4%）。这 5 个囊肿（29.4%）为 CE3（过渡型），9 个（52.9%）为 CE4（非活性），3 个（17.6%）为 CE5（非活性）。大多数囊肿来自具有阿富汗普什图族血统的 CE 患者（44/56；78.6%），而 12.5%（7/56）来自巴基斯坦普什图族血统的患者。大多数（41/56；73.2%）患者报告与狗有密切接触。使用 12SrRNA 引物，鉴定出 33 个囊肿是由细粒棘球绦虫亚种严格（s.s.）引起的。对其余 23 个样本评估了线粒体编码细胞色素 C 氧化酶 1（mt-CO1）。从这 23 个样本中的 6 个中获得了 PCR 产物。这 6 个样本中有 1 个被鉴定为加拿大棘球绦虫（G6/7）。mt-CO1 基因的单倍型分析显示出高单倍型和低核苷酸多样性。mt-CO1 序列有 26 个多态性位点，其中 65.3%（17/26）为简约信息丰富。加拿大棘球绦虫 mt-CO1 单倍型网络由 11 个单倍型组成，其中主要有中央单倍型。总之，看来细粒棘球绦虫亚种和加拿大棘球绦虫（G6/7）在巴基斯坦西北部地区流行。需要进一步的分子流行病学研究来探索寄生虫的本地遗传多样性。
