A longitudinal evaluation of Treponema pallidumPCR testing in early syphilis

Abstract

BackgroundSyphilis is a growing public health problem among men who have sex with men (MSM) globally. Rapid and accurate detection of syphilis is vital to ensure patients and their contacts receive timely treatment and reduce ongoing transmission.MethodsWe evaluated a PCR assay for the diagnosis of Treponema pallidum using swabs of suspected early syphilis lesions in longitudinally assessed MSM.ResultsWe tested 260 MSM for T pallidum by PCR on 288 occasions: 77 (26.7%) had early syphilis that was serologically confirmed at baseline or within six weeks, and 211 (73.3%) remained seronegative for syphilis. Of 55 men with primary syphilis, 49 were PCR positive, giving a sensitivity of 89.1% (95% CI: 77.8%-95.9%) and a specificity of 99.1% (95% CI: 96.5%-99.9%). Of 22 men with secondary syphilis, 11 were PCR positive, giving a sensitivity of 50% (95% CI: 28.2%-71.8%) and a specificity of 100% (95% CI: 66.4%-71.8%). Of the 77 syphilis cases, 43 (56%) were HIV positive and the sensitivity and specificity of the PCR test did not vary by HIV status. The PCR test was able to detect up to five (10%) primary infections that were initially seronegative, including one HIV positive man with delayed seroconversion to syphilis (72 to 140 days) and one HIV positive man who did not seroconvert to syphilis over 14 months follow-up. Both men had been treated for syphilis within a week of the PCR test.ConclusionsT pallidum PCR is a potentially powerful tool for the early diagnosis of primary syphilis, particularly where a serological response has yet to develop.

Cross‐sectional study of Treponema pallidum PCR in diagnosis of primary and secondary syphilis

“…Gayet‐Ageron et al . reported a Tp PCR sensitivity of 75.9% for secondary syphilis, and other studies reported a sensitivity as low as 43–50% in secondary syphilis . These contradictory results could be related to different methodology used as PCR test target sequence or reference test.…”

2014 European guideline on the management of syphilis

“…Materiałem do badań mogą być tkanki, płyn mó-zgowordzeniowy (PMR), krew (metoda o niskiej czułości) itp. [14][15][16][17][18][19][20]. Nie istnieje na świecie jedna platforma PCR zaakceptowana do diagnostyki kiły, dlatego należy używać tylko metod poddanych dokładnej walidacji i z zastosowaniem odpowiedniej kontroli jakości.…”

Azithromycin-Resistant Syphilis-Causing Strains in Sydney, Australia: Prevalence and Risk Factors

“…All requests for T. pallidum PCR analysis in Sydney are sent to a single laboratory. (21). All samples testing positive by PCR for the tpp47 target during this period were stored at Ϫ20°C until required.…”