Prevalence of Entamoeba histolytica and other enteral parasitic diseases in the metropolitan region of Belo Horizonte, Brazil. A cross-sectional study

ABSTRACT BACKGROUND: Enteral parasitic diseases are a public health problem in nations with low economic development and in settings with poor sanitation. Amebiasis is the second most frequent form of parasitosis, with a high burden of disease. Knowledge of the prevalence of enteroparasitoses in a given region is useful for planning clinical decision-making. Thus, the aim of this study was to estimate the prevalence of enteral parasitic diseases, especially amebiasis, through analysis on stool samples from public and private laboratories in a metropolitan area in southeastern Brazil. DESIGN AND SETTING: Cross-sectional study conducted in the metropolitan region of Belo Horizonte, Brazil. METHODS: We evaluated 6,289 fecal samples from one private and one public laboratory. The samples were concentrated by means of spontaneous sedimentation, and those that were positive for Entamoeba histolytica or Entamoeba dispar in optical microscopy analyses were processed to obtain deoxyribonucleic acid, with subsequent identification through the polymerase chain reaction. RESULTS: Among the stool samples, 942 (15.0%) had parasitic infections; 73 (1.2%) of these were helminthic infections and 847 (13.5%) were protozoan infections, caused mainly by Escherichia coli (6.0%), Endolimax nana (5.2%) and Giardia lamblia (1.2%). Infections due to Entamoeba histolytica or Entamoeba dispar occurred in 36 samples (0.6%) and the polymerase chain reaction revealed five (13.9%) as Entamoeba histolytica. CONCLUSION: The prevalence of enteral parasitic diseases is high in the metropolitan region of Belo Horizonte, although amebiasis may not be a problem.

背景：肠道寄生虫病是经济欠发达地区及卫生条件恶劣国家的公共卫生问题。阿米巴病是第二常见的寄生虫病，疾病负担沉重。掌握特定地区肠道寄生虫病的患病率，有助于规划临床决策。因此，本研究旨在通过分析巴西东南部贝洛奥里藏特都会区公立与私立实验室的粪便样本，估算肠道寄生虫病尤其是阿米巴病的患病率。

研究设计与地点：本研究为横断面研究，开展于巴西贝洛奥里藏特都会区。

研究方法：本研究共评估了取自1家私立实验室与1家公立实验室的6289份粪便样本。采用自然沉淀法对样本进行浓缩处理；对光学显微镜检测呈阳性的溶组织内阿米巴（Entamoeba histolytica）或迪斯帕内阿米巴（Entamoeba dispar）样本，提取脱氧核糖核酸（DNA），随后通过聚合酶链式反应（PCR）完成鉴定。

研究结果：所有粪便样本中，942份（15.0%）检出寄生虫感染；其中73份（1.2%）为蠕虫感染，847份（13.5%）为原虫感染，主要病原体为大肠埃希菌（6.0%）、微小内蜒阿米巴（5.2%）及蓝氏贾第鞭毛虫（1.2%）。溶组织内阿米巴或迪斯帕内阿米巴感染共检出36份（0.6%），经聚合酶链式反应鉴定，其中5份（13.9%）为溶组织内阿米巴感染。

结论：贝洛奥里藏特都会区肠道寄生虫病患病率较高，但阿米巴病或并非主要公共卫生问题。