Shlim D R, Hoge C W, Rajah R, Rabold J G, Echeverria P
Canadian International Water and Energy Consultants Clinic, Kathmandu, Nepal.
Clin Infect Dis. 1995 Jul;21(1):97-101. doi: 10.1093/clinids/21.1.97.
Although the pathogenicity of Blastocystis hominis has been extensively debated in the medical literature, controlled studies of the association between B. hominis and diarrhea are lacking. We conducted a case-control study among expatriates and tourists in Kathmandu, Nepal, in which we compared the prevalence of the organism among patients with diarrhea to that among a control group without diarrhea. B. hominis was detected in 56 (30%) of 189 patients with diarrhea, compared with 40 (36%) of 112 asymptomatic controls. Patients with diarrhea were significantly more likely to have > or = 10 B. hominis organisms per high-power (400x) field than were controls. However, among the 25 patients with this concentration of organisms, other enteric pathogens were detected in 17 (68%). Only 8 (4%) of 189 patients with diarrhea had > or = 10 B. hominis organisms per high-power field detected in the absence of other pathogens, compared with 5 (5%) of 112 asymptomatic controls. Thus, B. hominis in higher concentrations was not associated with diarrhea. There were no specific symptoms associated with B. hominis infection, and the presence of higher concentrations of the organism in stool was not associated with more-severe symptoms. Despite the high prevalence of the organism among travelers and expatriates in Nepal, the results of this study suggest that B. hominis does not cause diarrhea in this population.
虽然人芽囊原虫的致病性在医学文献中已被广泛讨论，但缺乏关于人芽囊原虫与腹泻之间关联的对照研究。我们在尼泊尔加德满都的外籍人士和游客中开展了一项病例对照研究，比较了腹泻患者与无腹泻对照组中该病原体的患病率。189例腹泻患者中有56例（30%）检测到人芽囊原虫，而112例无症状对照中有40例（36%）检测到。腹泻患者每高倍视野（400倍）中检出≥10个人芽囊原虫的可能性显著高于对照组。然而，在这25例病原体浓度达到此水平的患者中，17例（68%）检测到其他肠道病原体。在无其他病原体情况下，189例腹泻患者中仅8例（4%）每高倍视野检出≥10个人芽囊原虫，而112例无症状对照中有5例（5%）。因此，高浓度的人芽囊原虫与腹泻无关。人芽囊原虫感染无特定症状，粪便中该病原体浓度较高与更严重症状无关。尽管尼泊尔的旅行者和外籍人士中该病原体患病率很高，但本研究结果表明人芽囊原虫在该人群中不引起腹泻。
