Publisher Correction: Comparison of platforms for testing antibodies to Chlamydia trachomatis antigens in the Democratic Republic of the Congo and Togo.

The Acknowledgements section in the original version of this Article was incomplete. It now reads: “The surveys in the Democratic Republic of the Congo were generously supported by the American People through the United States Agency for International Development (USAID) via its ENVISION project (cooperative agreement number OAA-A-11-00048) and Act to End NTDs | East program (cooperative agreement No. 7200AA18CA00040), implemented by RTI International. The surveys and activities in the Togolese Republic were generously supported by the American People through the USAID via its End Neglected Tropical Diseases in Africa project (cooperative agreement number AID-OAA-A-10-00050), managed by FHI 360. Laboratory work at CDC was funded through an interagency agreement with USAID. Disclaimer: The authors alone are responsible for the views expressed in this article and they do not necessarily represent the views, decisions or policies of the institutions with which they are affiliated. The authors declare no competing interests.

Comparison of platforms for testing antibodies to Chlamydia trachomatis antigens in the Democratic Republic of the Congo and Togo.

Trachoma, caused by repeated ocular infection with Chlamydia trachomatis (Ct), is targeted for elimination as a public health problem. Serological testing for antibodies is promising for surveillance; determining useful thresholds will require collection of serological data from settings with different prevalence of the indicator trachomatous inflammation-follicular (TF). Dried blood spots were collected during trachoma mapping in two districts each of Togo and Democratic Republic of the Congo. Anti-Ct antibodies were detected by multiplex bead assay (MBA) and three different lateral flow assays (LFA) and seroprevalence and seroconversion rate (SCR) were determined. By most tests, the district with > 5% TF (the elimination threshold) had five-sixfold higher seroprevalence and tenfold higher SCR than districts with < 5% TF. The agreement between LFA and MBA was improved using a black latex developing reagent. These data show optimization of antibody tests against Ct to better differentiate districts above or below trachoma elimination thresholds

Evaluating the yaws diagnostic gap: A survey to determine the capacity of and barriers to improving diagnostics in all yaws-endemic countries

BACKGROUND: Yaws, caused by Treponema pallidum subsp. pertenue, is a skin neglected tropical disease. It is targeted for eradication by 2030, primarily using mass drug administration (MDA) with azithromycin. Traditionally, diagnosis of yaws has relied on clinical examination and serological testing. However, these approaches have poor diagnostic performance. To achieve eradication, more accurate diagnostics are required to determine whether MDA should be initiated or continued as well as for post-elimination surveillance. Molecular tools will be crucial for detecting antimicrobial resistant cases, which have the potential to derail eradication efforts. In order to determine the feasibility of introducing novel, more accurate, diagnostics for yaws surveillance purposes, it is necessary to understand current in-country diagnostic capacity. This study therefore aimed to understand the current capacity of, and challenges to, improving diagnostics for yaws in all yaws-endemic countries worldwide. METHODOLOGY/ PRINCIPLE FINDINGS: An online survey was sent to all 15 yaws-endemic countries in July 2021. The survey asked about past prevalence estimates, the availability of different diagnostic tools, and perceived barriers to enhancing capacity. Fourteen countries responded to the survey, four of which did not have a current National Policy for yaws eradication in place. Over 95% of reported that yaws cases from the past five years had not been confirmed with serological or molecular tools, largely due to the limited supply of rapid serological tests. Only four countries reported having operational laboratories for molecular yaws diagnosis, with only one of these having a validated assay to detect azithromycin resistance. CONCLUSIONS AND SIGNIFICANCE: This study highlights the diagnostic capacity constraints across all respondent countries. Countries are in need of access to a sustainable supply of serological tests, and development of molecular testing facilities. Sufficient sustainable funding should be made available to ensure that appropriate diagnostic tools are available and utilised