Syphilis is a chronic bacterial infection caused by the spirochaete Treponema pallidum. It is usually acquired by sexual contact but may also be transmitted by transfusion of infected blood.
An estimated 11.76 million cases of syphilis occurred worldwide in 1999. The incidence and prevalence of the disease varies widely in different parts of the world and may fluctuate considerably within any one region from year to year. The highest rates are seen in developing countries, particularly sub-Saharan Africa and South and Southeast Asia.
Initial infection typically produces sores, known as chancres, at the site of infection. The bacteria then move throughout the body, damaging many organs over time. The course of the disease is divided into four stages. An infected person who has not been treated may infect others during the first two stages, which usually last one to two years. In its late stages, untreated syphilis, although not contagious, can cause serious and irreversible cardiovascular and neurological problems.
Diagnosis usually depends on the demonstration of antibodies in the blood. Two types of antibody are produced in response to infection, non-specific anti-lipid reagin antibody and specific anti-treponemal antibody. These appear soon after infection; the specific anti-treponemal antibodies may persist for many years, whereas the reagin antibodies may disappear after treatment.
Test formats
From simple RPR tests through to highly sensitive EIA kits, Lab21 produces a range of tests which meet all laboratory requirements for syphilis screening and diagnosis:
RPR: a fast, reliable and robust assay for the detection of non treponemal rapid plasma reagin antibodies in human serum or plasma. The test consists of modified VDRL antigen containing microparticulate carbon which aggregates in the presence of reagin type antibodies, indicating a positive result which can be read macroscopically. Click here to view our RPR microsite.
TPHA: a fast, reliable and robust haemagglutination assay for detection of treponemal antibodies in human serum and plasma. TPHA uses preserved avian erythrocytes coated with antigens of T. pallidum (Nichols strain), which will bind with specific antibody present in patient’s serum or plasma. High flexibility is achieved with wide range of kit sizes available including a specially configured kit for use on the Beckman Coulter PK7200 and 7300 instruments. Click here to view our TPHA microsite.
Total Antibody EIA: a one step sandwich assay with with 60 minutes total incubation and the highest sensitivity and specificity in class as determined by MHRA. The assay is a total antibody assay (IgA, IgG, IgM) for detection during all stages of infection and features colour coded reagents for visual and automated addition verification. Click here to view our syphilis total antobody EIA microsite.
IgM EIA: is a fast and specific two step capture EIA for detection of T.pallidum specific IgM for early stage diagnosis. The assay features a 2 hour assay time with no pre-assay sample dilution required, with specially formulated recombinant antigens to enhance reactivity and produce consistent and reproducible performance. Click here to view our syphilis IgM EIA microsite.
Rapid Tests: syphilis antigen is immobilised on a membrane to detect Treponemal antibodies (IgG and IgM) qualitatively and selectively to provide accurate diagnosis of syphilis. Click here to view our rapid tests page.