El-Malky M M, Mowafy N M, Zaghloul D A, Al-Harthi S A, El-Bali M A, Mohamed R T, Bakri R A, Mohamed A A, Elmedany S
Department of Medical Parasitology, Faculty of Medicine, Umm AL-Qura University, Makkah, Kingdom of Saudi Arabia.
Department of Medical Parasitology, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
Trop Biomed. 2018 Mar 1;35(1):76-81.
Cryptosporidiosis has been identified as a significant underlying cause of morbidity and mortality worldwide. Studies in high and low income countries have recognized the importance of Cryptosporidium as a cause of diarrhea. The objectives of the current study were to determine the prevalence rate and genotypes of Cryptosporidiumin in diarrheic children in Makkah Region. A total of 1,380 fecal samples were collected from children aged up to 14 years attending 3 major hospitals of Makkah between March 2015 and March 2016. Stool collected were subjected to direct microscopic examination and crypto antigen detection using ImmunoCard STAT, Cryptosporidium/Giardia rapid test. Part of each positive stool sample was kept frozen at -20ºC for molecular characterization. Initial screening by immunochromatographic detection kit revealed 23 positive cases. PCR was performed for positive cases by amplification of a piece of the gene encoding the small (18S) subunit of rRNA producing a 435-438 bp product. Cryptosporidium genotyping was performed by RFLP analysis of PCR products. Genotyping revealed 18 cases C. hominis genotype, 4 cases C. parvaum genotype and one sample failed to be amplified. The data revealed a higher incidence of the common human species C. hominis (81.8%). The detection of both C. hominis and C. parvaum genotypes point to the possibility of both anthroponotic and zoonotic transmission routes occurring in Makkah region. Further studies are needed to verify the subgenotypes of Cryptosporidium to elucidate the real transmission modes and hence plan for effective control strategies.
隐孢子虫病已被确认为全球发病和死亡的一个重要潜在原因。在高收入和低收入国家开展的研究已认识到隐孢子虫作为腹泻病因的重要性。本研究的目的是确定麦加地区腹泻儿童中隐孢子虫的流行率和基因型。2015年3月至2016年3月期间，从麦加3家主要医院就诊的14岁及以下儿童中总共收集了1380份粪便样本。所收集的粪便进行直接显微镜检查，并使用免疫卡STAT隐孢子虫/贾第虫快速检测试剂盒检测隐孢子虫抗原。每个阳性粪便样本的一部分保存在-20℃用于分子特征分析。通过免疫层析检测试剂盒进行初步筛查发现23例阳性病例。对阳性病例进行PCR，扩增编码核糖体RNA小（18S）亚基的一段基因，产生435 - 438 bp的产物。通过对PCR产物进行限制性片段长度多态性（RFLP）分析进行隐孢子虫基因分型。基因分型显示18例为人微小隐孢子虫基因型，4例为牛微小隐孢子虫基因型，1个样本未能扩增。数据显示常见的人源物种人微小隐孢子虫的发病率较高（81.8%）。人微小隐孢子虫和牛微小隐孢子虫基因型的检测表明，麦加地区可能存在人传人及人畜共患病传播途径。需要进一步研究以验证隐孢子虫的亚型，阐明实际传播模式，从而制定有效的控制策略。
