Seroepidemiological analysis of toxoplasmosis in college students

Background Toxoplasmosis is a zoonosis caused by an obligate intracellular parasite, Toxoplasma gondii, which affects warm-blooded animals including humans. Its prevalence rates usually vary in different regions of the planet. Methods In this study, an analysis of the seroprevalence of toxoplasmosis among Brazilian students was proposed by means of IgG specific antibodies detection. The presence of anti-Toxoplasma gondiiantibodies by indirect fluorescent antibody test (IFAT) was also evaluated in order to compare it with enzyme-linked immunosorbent assay (ELISA) and to assess the use of 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and o-phenylenediamine dihydrochloride chromogens. Results The IFAT method showed a seroprevalence of 22.3%. These results were similar to those obtained by ELISA (24.1%). The seroprevalence was directly estimated from the IgG avidity, which showed that in a sample of 112 students, three of them had acute infection, an incidence of 1.6% in the studied population. Conclusion In this study, the use of different chromogenic substrates in immunoenzymatic ELISA assays did not display different sensitivity in the detection of T. gondii-reagent serum. The extrapolation of results to this population must be carefully considered, since the investigation was conducted on a reduced sample. However, it allows us to emphasize the importance of careful and well prepared studies to identify risk factors for toxoplasmosis, to adopt preventive measures and to offer guidance to at-risk populations about the disease.

背景 弓形体病（Toxoplasmosis）是由专性胞内寄生虫刚地弓形虫（Toxoplasma gondii）引发的人兽共患病，可感染包括人类在内的所有温血动物，其流行率在全球不同地区存在显著差异。
方法 本研究针对巴西学生群体的弓形体病血清流行率展开分析，采用特异性IgG抗体检测方法。同时通过间接荧光抗体试验（indirect fluorescent antibody test, IFAT）检测抗刚地弓形虫抗体，将其与酶联免疫吸附试验（enzyme-linked immunosorbent assay, ELISA）进行比对，并评估2,2′-联氮双(3-乙基苯并噻唑啉-6-磺酸)与邻苯二胺二盐酸盐两种生色底物的应用效果。
结果 间接荧光抗体试验的血清流行率为22.3%，该结果与酶联免疫吸附试验所得的24.1%相近。研究还通过IgG亲和力直接估算血清流行率：在112名学生的受试样本中，共3人呈急性感染，占研究群体的1.6%。
结论 本研究表明，免疫酶联ELISA检测中使用不同生色底物，在检测刚地弓形虫阳性血清时未表现出显著的灵敏度差异。由于本次研究样本量有限，将研究结果外推至整体研究群体时需谨慎评估。尽管如此，本研究仍强调需开展严谨规范的相关研究，以明确弓形体病的危险因素，制定针对性预防措施，并为高危人群提供该疾病的健康指导。