Performance and costs of a rapid syphilis test in an urban population at high risk for sexually transmitted infections

INTRODUCTION

Rapid syphilis screening could facilitate case-identification in populations at high risk for sexually transmitted infections (STI). The aim of this study was to compare the performance and the cost-effectiveness of a rapid immunochromatography syphilis test with a traditional ELISA screening test in patients with suspected infectious syphilis or patients at high risk for STI/syphilis.

METHODS

Consecutive patients attending a STI clinic cosensually underwent serological testing with two different tests. Sensitivity, specficity, Positive Predictive Values, Negative Predictive Values and effectiveness of the two tests were evaluated with respect to definitive diagnosis.

RESULTS

In our population, the immunochromatography essay (Abbott Determine Syphilis TP) had a sensitivity of 95.0% (95% CI 88.7-97.8) and a specificity of 97.7% (95% CI 94.7-99.0). The ELISA test had a sensitivity of 95.0% (95% CI 88.8-97.9) and a specificity of 97.2% (95% CI 94.1-98.7). The Positive Predictive Value for ELISA was 94.1% (95% CI 87.6-97.3) and 95.0% (95% CI 88.7-97.8) for the rapid test. The Negative Predictive Value was 97.7% (95% CI 94.7-99) for both ELISA and the rapid tests. The cost-effectiveness analysis showed that the rapid test was less expensive than ELISA (EUR 26.46 vs EUR 40.57) and yielded a similar number of right diagnoses.

CONCLUSIONS

The Abbott Determine Syphilis TP test is an accurate, easy and inexpensive test that could facilitate the rapid detection of syphilis in high-risk urban patients.

Successful simplification of HAART in patients with acute primary HIV infection

Aggressive treatment has been advocated for the management of primary HIV infection (PHI), but the composition and the optimal duration of therapy are still to be determined. In addition, time to undetectable viral load (VL), rate and duration of VL suppression as well as subsequent therapeutic choices remain issues widely debated. We evaluated the rate and duration of VL suppression in 12 consecutive patients with PHI given triple-drug treatment with zidovudine, lamivudine and indinavir (highly active antiretroviral therapy, HAART) at onset of the acute illness and subsequently switched to a simplified 2-NRTI-based regimen once VL suppression was maintained for at least 6 months. Throughout the study, no patient discontinued treatment because of symptoms attributed to the study medications. In the study population, undetectable VL was achieved after a median of 84 days (range: 67-135) on HAART and was maintained for a median of 194 days (range: 179-205) before simplification. After switching to simplified maintenace, undetectable VL was maintained in all patients for at least 6 months. Only one patient experienced virological failure, plasma HIV-RNA remaining suppressed for a median foliow-up of 33 months (15-54) and T-CD4+ being steadily higher than 500/mL in the remaining patients. Our results suggest that simplification of HAART in patients promptly treated during PHI and maintaining undetectable VL for at least 6 months before simplification may be a valid option capable of controlling viral replication and maintaining an optimal immunological profile for a prolonged time.