initial d street stage manual transmission

The sensitivity and specificity of serological tests vary depending on the type of test and stage of the disease (Table (Table1). In fact, in North America, the majority of syphilis cases are identified at the latent stage by serological tests. Latent syphilis can only be diagnosed by serological tests.

Despite their shortcomings and the complexity of interpretation, serological tests are the mainstay in the diagnosis and follow-up of syphilis. A confirmed serological test result is indicative of the presence of treponemal antibodies but does not indicate the stage of disease and, depending on the test, may not differentiate between past and current infection. A reactive nontreponemal test is then confirmed by a treponemal test. If lesion exudate or tissue is available, direct examination is performed, followed by a nontreponemal serology test. All treponemal tests use T pallidum or its components as the antigen.

All nontreponemal tests measure both immunoglobulin (Ig) G and IgM antiphospholipid antibodies formed by the host in response to lipoidal material released by damaged host cells early in infection and lipid from the cell surfaces of the treponeme itself. Serological tests fall into two categories: nontreponemal tests for screening, and treponemal tests for confirmation (Figure (Figure1). Indirect diagnosis is based on serological tests for the detection of antibodies. Direct diagnostic methods include the detection of T pallidum by microscopic examination of fluid or smears from lesions, histological examination of tissues or nucleic acid amplification methods such as polymerase chain reaction (PCR). In some stages, the disease may be asymptomatic, and there are problems in diagnosing very early syphilis, neurosyphilis, asymptomatic congenital syphilis and syphilis in intravenous drug users and persons coinfected with serologically cross-reacting agents and HIV.Īlthough T pallidum cannot be grown in culture, there are many tests for the direct and indirect diagnosis of syphilis. The stage of the disease at which the patient presents has implications for diagnosis and treatment. The ulcers that appear in primary and secondary syphilis are rich in treponemes venereal transmission occurs through direct contact with these lesions. Syphilis progresses through distinct primary, secondary, latent and tertiary stages. Therefore, it is mandatory that the clinical diagnosis is always supported by appropriate laboratory tests and that the test results are interpreted with reference to the patient's history and physical examination findings. Syphilis has diverse clinical manifestations and shares many clinical features with other treponemal and nontreponemal diseases. The etiological agent of syphilis is Treponema pallidum.

Initial d street stage manual transmission