Evaluation of a Digital Flocculation Reader for the Rapid Plasma Reagin Test for the Serological Diagnosis of Syphilis

We described the ASiManager-AT digital flocculation reader to demonstrate concordance between visual and digital readings of the rapid plasma reagin test for detection of antibodies in the serum ofpatients with syphilis.Aqualitative and quantitative rapid plasma reagin was performed on each serum samples giving a concordance of98.6%and 99.7%, respectively, for reactives and 100% for nonreactives. T he Centers for Disease Control and Prevention (CDC) rec- ommends syphilis serologic scree ning with a nontrepone- mal test, such as the rapid plasma reagin (RPR) to identify persons with possible untreated infection. 1 The RPRis a mac- roscopic, nontreponemal flocculation card test used to screen for antibodies in patients suspected of having contracted syph- ilis.2-4 The RPR test is highly subjective and lends itself to misinterpretation when performing the qualitative or quantita- tive tests. t observers can arrive at t conclu- sions, especially when reading the endpoint of a quantitative test or the interpretation of a minimal reactive or slight rough- ness in the qualitative test. The ASiManager-AT digital floc- culation reader is designed to read objectively each well of the RPR test. The purpose of the study was to demonstrate con- cordance between the visual and digital readings and to avoid any bias in reading the test.