Multiple methodologies have been used to detect antibodies to Babesia microti. Use of an indirect immunofluorescence assay (IFA) has been the most widely used approach, but IFAs have varied as to which antibody class or classes are being detected and in regard to cutoff titers. In this study, 245 different patients with polymerase chain reaction (PCR)-confirmed B. microti infection were tested by a polyvalent IFA using serum collected within 3 days of the date the blood sample for PCR testing was obtained. Of the 245 patients, 243 (99.2%) had a positive serologic test result (i.e., ≥1:64). Of the 243 patients who were seropositive, 242 (99.6%) had a titer of ≥1:256, 236 (97.1%) had a titer of ≥1:512, and 210 (86.4%) had a titer of ≥1:1024. In conclusion, high titer seropositivity based on a polyvalent IFA is to be expected at the time of PCR confirmation of active babesiosis in clinical practice.

中文翻译：

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通过PCR在纽约州诊断的245例患者对小肠贝氏杆菌血清反应的频率和大小。

已经使用多种方法来检测针对小巴贝虫的抗体。间接免疫荧光测定法（IFA）的使用是最广泛使用的方法，但是IFA对于要检测的抗体种类和截断效价有所不同。在这项研究中，使用多价IFA对245名不同的经聚合酶链反应（PCR）确诊的小肠芽孢杆菌感染的患者进行了检测，使用的是在获得用于PCR测试的血液样本之日起3天内收集的血清。在245名患者中，有243名（99.2％）的血清学检查结果为阳性（即≥1：64）。在243例血清反应阳性的患者中，242（99.6％）的效价≥1：256，236（97.1％）的效价≥1：512，210（86.4％）的效价≥1：1024 。结论，