The VDRL and RPR tests are flocculation tests for reagin and are used in screening for syphilis. The VDRL test uses heat-inactivated serum and can be made on slides or in tubes. The RPR test uses unheated serum or plasma, which is added to a reagent-treated plasma card. Automated procedures have been adapted for multichannel analyzers.²⁹

Note that these tests are not specific for antibodies to T. pallidum, and many factors, including laboratory procedures, may cause false-positive results (see Table 3-12).

• Results are reported qualitatively as strongly reactive, reactive, weakly reactive, or negative. A degree of quantification is possible by diluting the serum and reporting the highest titer that remains positive. Positive results must be further evaluated either by repeat testing or with tests specific for antitreponemal antibodies.30

• Many factors, including laboratory procedures, may cause false-positive results (see Table 3-12).

• Routine screening for possible syphilis
• Known or suspected exposure to syphilis, including congenital syphilis
• Verification of an antigen-antibody reaction to reagin, although a positive result is not necessarily diagnostic for syphilis
• Monitoring of response to treatment for syphilis, with effective treatment indicated by decreasing titers

Nursing Care Before the Procedure

Client preparation is the same as that for any study involving the collection of a peripheral blood sample (see Appendix I).

• A thorough history should be obtained to identify possible causes of false-positive results (see Table 3-12).
• It is recommended that alcohol ingestion be avoided for 24 hours before the test.

A venipuncture is performed and the sample collected in a red-topped tube. The sample must be handled gently to avoid hemolysis and transported promptly to the laboratory.

• For neonates, a sample of cord blood may be obtained at delivery. Subsequent samples of venous blood from the infant may be required if the mother's titer is lower than that of the infant, indicating active syphilis in the infant despite successful treatment of the mother.

Nursing Care After the Procedure

Care and assessment after the procedure are the same as for any study involving the collection of a peripheral blood sample.

• Abnormal values: Note and report a positive result and degree of reactivity. Assess for pregnancy and sexual contacts. Ensure that positive results are reported to the health department for follow-up and treatment of sexual contacts. Administer ordered antibiotic medication regimen. Instruct in importance of preventive measures to take during sexual activity, especially if pregnant, and the screening and treatment of sexual partner. Inform that the test should be repeated every 3 months for at least 1 year or until the reaction becomes negative. Provide a sensitive, nonjudgmental environment for the client.