Abstract:
Murine typhus is a neglected but widespread infectious disease that results in acute fever. The immunofluorescence assay (IFA) is the \"gold standard\" to identify IgM or IgG antibodies, although there is a lack of standardization in methodologies. The objective of this review is to summarize 1) the differences in published methodologies, 2) the diagnostic cutoff titers, and 3) the justification of diagnostic cutoffs. Searches were performed by combining the following search terms: \"murine typhus,\" \"rickettsia typhi,\" \"immunofluorescence,\" \"IFA,\" and \"serologic\" with restrictions (i.e., \"rickettsia typhi\" or \"murine typhus,\" and \"IFA\" or \"immunofluorescence,\" or \"serologic*\"). The search identified 78 studies that used IFA or immunoperoxidase assay (IIP) antibody cutoffs to diagnose murine typhus, 39 of which were case series. Overall, 45 studies (57.7%) provided little to no rationale as to how the cutoff was derived. Variation was seen locally in the cutoff titers used, but a 4-fold or greater increase was often applied. The cutoffs varied depending on the antibody target. No consensus was observed in establishing a cutoff, or for a single-value diagnostic cutoff. In conclusion, there is a lack of consensus in the establishment of a single-value cutoff. Further studies will need to be executed at each distinct geographic location to identify region-specific cutoffs, while also considering background antibody levels to distinguish between healthy and infected patients.
摘要:
鼠斑疹伤寒是一种被忽视但广泛存在的传染病,可导致急性发热。免疫荧光测定法(IFA)是鉴定IgM或IgG抗体的“金标准”,尽管方法缺乏标准化。本综述的目的是总结1)已发表方法的差异,2)诊断截止滴度,和3)诊断截止的理由。通过结合以下搜索词进行搜索:“鼠斑疹伤寒,\"\"伤寒立克次体,\"\"免疫荧光,\"\"IFA,“和”血清学“有限制(即,\"伤寒立克次体\"或\"鼠伤寒,\"和\"IFA\"或\"免疫荧光,\"或\"血清学*\")。搜索确定了78项研究,这些研究使用IFA或免疫过氧化物酶测定(IIP)抗体截止值来诊断鼠斑疹伤寒,其中39个是案例系列。总的来说,45项研究(57.7%)几乎没有提供关于如何得出临界值的理由。在使用的截止滴度中局部观察到变化,但通常增加4倍或更多。截止值根据抗体靶标而变化。在建立分界点方面没有达成共识,或单值诊断截止值。总之,在建立单一价值截止方面缺乏共识。需要在每个不同的地理位置进行进一步的研究,以确定特定区域的截止值。同时还考虑背景抗体水平来区分健康和感染患者。