Mirrezaie Ehsanallah, Beiromvand Molouk, Tavalla Mehdi, Teimoori Ali, Mirzavand Somayeh
Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, P.O. Box 61357-15794, Ahvaz, Iran.
Department of Parasitology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Acta Parasitol. 2019 Jun;64(2):376-383. doi: 10.2478/s11686-019-00051-x. Epub 2019 Apr 9.
Giardia duodenalis, one of the most common intestinal protozoa, infects a wide range of vertebrates, including humans and animals.
In this study, 84 Giardia duodenalis positive stool samples were collected from 3580 patients attending the Imam Ali Hospital and two public health centers in Andimeshk County, southwestern Iran. Stool samples were examined initially by microscopy, and then G. duodenalis was confirmed by SSU rRNA gene and genotypes were determined by amplification of the gdh and β-giardin genes.
The SSU rRNA, gdh, and β-giardin genes were successfully amplified in 89.3%, 58.3%, and 51.2% samples, respectively. Of the positive samples for gdh and β-giardin, 40 isolates were successfully sequenced. Twenty-three isolates belonged to assemblage A, sub-assemblage AII, and 17 belonged to assemblage B. Of the 24 successfully amplified asymptomatic cases, 12 belonged to assemblage A and 12 belonged to assemblage B.
The current study found that 64.3% of the patients were asymptomatic. From an epidemiological point of view, the high percentage of asymptomatic patients is important because of their role in the transmission of Giardia. The predominant assemblage was assemblage A, sub-assemblage AII. In general, therefore, it seems that most infections are probably transmitted by anthroponotic pathways in the region.
十二指肠贾第虫是最常见的肠道原生动物之一，可感染包括人类和动物在内的多种脊椎动物。
在本研究中，从伊朗西南部安迪梅什克县的伊玛目阿里医院和两个公共卫生中心的3580名患者中收集了84份十二指肠贾第虫阳性粪便样本。粪便样本首先通过显微镜检查，然后通过小亚基核糖体RNA（SSU rRNA）基因确认十二指肠贾第虫，并通过扩增谷氨酸脱氢酶（gdh）和β-贾第虫蛋白（β-giardin）基因确定基因型。
SSU rRNA、gdh和β-giardin基因分别在89.3%、58.3%和51.2%的样本中成功扩增。在gdh和β-giardin阳性样本中，40个分离株成功测序。23个分离株属于A群，AII亚群，17个属于B群。在24例成功扩增的无症状病例中，12例属于A群，12例属于B群。
本研究发现64.3%的患者无症状。从流行病学角度来看，无症状患者比例高很重要，因为他们在贾第虫传播中起作用。主要菌群是A群，AII亚群。因此，总体而言，该地区的大多数感染似乎可能通过人传人途径传播。
