Abstract
The recommendations for diagnostic tests for investigating syphilis are part of the Clinical Protocol and Therapeutic Guidelines for Comprehensive Care for People with Sexually Transmitted Infections and the Technical Manual for Syphilis Diagnosis, published by the Brazilian Ministry of Health. These recommendations were developed based on scientific evidence and discussions with a panel of experts. This article presents direct tests to detect Treponema pallidum in lesions and algorithms that combine treponemal and non-treponemal antibody tests to assist in syphilis diagnosis, with the aim of contributing to the efforts of health service managers and health professionals in qualifying health care. The article also covers the use of non-treponemal tests to investigate neurosyphilis and guidelines for interpreting non-treponemal antibody titers in monitoring the treatment and diagnosis of congenital syphilis, as well as prospects for innovations in diagnosis. The critical role of rapid immunochromatographic treponemal tests for public health and for addressing syphilis is also highlighted.
Keywords:
Syphilis; Neurosyphilis; Congenital syphilis; Diagnosis
Highlighted excerpt: During the natural evolution of syphilis, activity periods with distinct clinical, immunological, and histopathological characteristics are interspersed with latent periods when there are no signs or symptoms, making access to tests critical for early diagnosis.
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Notes: a) The tests assessed and the analysis methodology are published in scientific articles
Note: a) Sample must be tested in pure and diluted form to eliminate the possibility of the prozone phenomenon; b) Sample must be diluted in factor 2 and undergo the non-treponemal test again. The results must be provided in titer values (e.g., 2, 4, 8...128) or the last dilution (e.g., 1:2, 1:4, 1:8...1:128) presenting reactivity; c) The detection of treponemal and non-treponemal antibodies suggests active syphilis; d) Treponemal test with a different methodology from the treponemal test already used in the second test algorithm. When the third test is not available, the results of each test must be released individually for assessment and clinical conduct; e) Detection of treponemal and non-treponemal antibodies suggests active syphilis. Probable false non-reagent results in the first treponemal test; f) Probable false-reaction result for syphilis in the non-treponemal test. Assess other clinical conditions besides syphilis that can generate reaction results in non-treponemal tests.
Note: a) Sample must be tested in pure and diluted form to eliminate the possibility of the prozone phenomenon; b) Sample must be diluted in factor 2 and undergo the non-treponemal test again. The results must be provided in titer values (e.g., 2, 4, 8...128) or the last dilution (e.g., 1:2, 1:4, 1:8...1:128) presenting reactivity; c) The detection of treponemal and non-treponemal antibodies suggests active syphilis; d) Treponemal test with a different methodology from the treponemal test already used in the algorithm as the first test. If the third test is not available, the results of each test must be released individually for assessment and clinical conduct;e) Detection of treponemal antibodies only suggests recent syphilis or serological scarring. Assess exposure to risk, signs, symptoms, and history of syphilis treatment for defining clinical conduct; f) Lack of detection of non-treponemal antibodies and non-confirmation of treponemal antibody reactivity suggests no syphilis. Probable false reagent results in the first treponemal test.