title: Failure of PCR to Detect Treponema pallidum ssp. pertenue DNA in Blood in Latent Yaws.
abstract: Yaws, caused by Treponema pallidum ssp. pertenue, is a neglected tropical disease closely related to venereal syphilis and is targeted for eradication by 2020. Latent yaws represents a diagnostic challenge, and current tools cannot adequately distinguish between individuals with true latent infection and individuals who are serofast following successful treatment. PCR on blood has previously been shown to detect T. pallidum DNA in patients with syphilis, suggesting that this approach may be of value in yaws. We performed real-time PCR for Treponema pallidum ssp. pertenue on blood samples from 140 children with positive T. pallidum Particle Agglutination (TPPA) and Rapid Plasma Reagin (RPR) tests and 7 controls (negative serology), all collected as part of a prospective study of yaws in the Solomon Islands. All samples were also tested by a nested PCR for T. pallidum. 12 patients had clinical evidence of active yaws whilst 128 were considered to have latent yaws. 43 children had high titre rapid plasma reagins (RPRs) of ≥1:32. PCR testing with both assays gave negative results in all cases. It is possible that the failure to detect T. pallidum ssp. pertenue in blood reflects lower loads of organism in latent yaws compared to those in latent infection with T. pallidum ssp. pertenue, and/or a lower propensity for haematogenous dissemination in yaws than in syphilis. As the goal of the yaws control programme is eradication, a tool that can differentiate true latent infection from individuals who are serofast would be of value; however, PCR of blood is not that tool.
authors.affiliation: Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom; The Hospital for Tropical Diseases, London, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Marks
authors.affiliation: Laboratory Reference and Research Branch, Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and Tuberculosis Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Samantha
authors.initials: S
authors.lastname: Katz
authors.affiliation: Laboratory Reference and Research Branch, Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and Tuberculosis Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Kai-Hua
authors.initials: KH
authors.lastname: Chi
authors.affiliation: Ministry of Health and Medical Services, Honiara, Solomon Islands.
authors.forename: Ventis
authors.initials: V
authors.lastname: Vahi
authors.affiliation: Laboratory Reference and Research Branch, Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and Tuberculosis Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Yongcheng
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom; The Hospital for Tropical Diseases, London, United Kingdom.
authors.forename: David C
authors.initials: DC
authors.lastname: Mabey
authors.affiliation: Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom; The Hospital for Tropical Diseases, London, United Kingdom.
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Solomon
authors.affiliation: Laboratory Reference and Research Branch, Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and Tuberculosis Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Cheng Y
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Laboratory Reference and Research Branch, Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and Tuberculosis Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Allan
authors.initials: A
authors.lastname: Pillay
mesh_terms: D002648:Child; D004269:DNA, Bacterial / Q000097:blood* / Q000235:genetics; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008542:Melanesia / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D060888:Real-Time Polymerase Chain Reaction; D014210:Treponema pallidum / Q000235:genetics / Q000302:isolation & purification*; D015001:Yaws / Q000175:diagnosis* / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial