Performance evaluation of the Elecsys syphilis assay for the detection of total antibodies to Treponema pallidum.

Syphilis is a health problem of increasing incidence in recent years that may have severe complications if not diagnosed and treated at an early stage. There are many diagnostic tests available for syphilis, but there is no gold standard, and diagnosis therefore usually relies upon a combination of tests. In this multicenter study, we evaluated the treponemal Elecsys syphilis assay for use in the diagnosis of syphilis in routine samples, i.e., when syphilis is suspected or during antenatal or blood donation screening. The sensitivity and specificity of the Elecsys syphilis assay were compared head to head with those of other treponemal assays used in routine clinical practice and were assessed in potentially cross-reactive samples from patients with Epstein-Barr virus, HIV, and Lyme disease. In a total of 8,063 syphilis-negative samples collected from routine diagnostic requests and blood donations, the Elecsys syphilis assay had a specificity of 99.88%. In 928 samples previously identified as syphilis positive, the sensitivity was 99.57 to 100% (the result is presented as a range depending on whether four initially indeterminate samples are included in the assessment). The specificity of the Elecsys syphilis assay in patients with other infections was 100%; no false-positive samples were identified.

Multicenter evaluation of the Elecsys® anti-HCV II assay for the diagnosis of hepatitis C virus infection.

Routine screening of patients at risk of hepatitis C virus (HCV) infection has become a priority given recent improvements in therapeutic options and the asymptomatic nature of most chronic infections. The aim of this study was to evaluate the performance of the Elecsys® Anti-HCV II assay, a new qualitative antibody immunoassay, compared with currently available assays, and assess its suitability for routine diagnostic testing. The sensitivity of the Elecsys® Anti-HCV II, ARCHITECT® Anti-HCV, AxSYM® HCV 3.0, PRISM® HCV, Vitros® ECi Anti-HCV, Elecsys® Anti-HCV, and ADVIA Centaur® HCV assays was compared using commercially available seroconversion panels and samples from patients known to be HCV positive and infected with HCV genotypes 1-6. Specificity was investigated using samples from blood donors, unselected hospitalized patients, and patients with potential cross-reacting factors or from high-risk groups. The Elecsys® Anti-HCV II assay detected more positive bleeds than the comparator assays, was more sensitive in recognizing early HCV infection, and correctly identified all 765 samples known to be HCV positive, regardless of genotype. The overall specificity of the Elecsys(®) Anti-HCV II assay was 99.84% (n=6,850) using blood donor samples, 99.66% (n=3,922) using samples from unselected hospitalized patients, and 99.66% (n=2,397) using samples from patients with potentially cross-reacting factors or from high-risk groups. The specificity of the Elecsys® Anti-HCV II assay was superior or equal to the comparator assays. In conclusion, the Elecsys® Anti-HCV II assay is a sensitive and specific assay suitable for routine use in the reliable detection of anti-HCV antibodies.