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

Trachoma in the Democratic Republic of the Congo: Results of 46 Baseline Prevalence Surveys Conducted with the Global Trachoma Mapping Project.

PURPOSE: Trachoma was suspected to be endemic in parts of the Democratic Republic of the Congo (DRC). We aimed to estimate prevalences of trachomatous inflammation-follicular (TF), trichiasis, and water and sanitation (WASH) indicators in suspected-endemic Health Zones. METHODS: A population-based prevalence survey was undertaken in each of 46 Health Zones across nine provinces of DRC, using Global Trachoma Mapping Project methods. A two-stage cluster random sampling design was used in each Health Zone, whereby 25 villages (clusters) and 30 households per cluster were sampled. Consenting eligible participants (children aged 1-9 years and adults aged ≥15 years) were examined for trachoma by GTMP-certified graders; households were assessed for access to WASH. RESULTS: A total of 32,758 households were surveyed, and 141,853 participants (98.2% of those enumerated) were examined for trachoma. Health Zone-level TF prevalence in 1-9-year-olds ranged from 1.9-41.6%. Among people aged ≥15 years, trichiasis prevalences ranged from 0.02-5.1% (95% CI 3.3-6.8). TF prevalence in 1-9-year-olds was ≥5% in 30 Health Zones, while trichiasis prevalence was ≥0.2% in 37 Health Zones. CONCLUSION: Trachoma is a public health problem in 39 of 46 Health Zones surveyed. To meet elimination targets, 37 Health Zones require expanded trichiasis surgery services while 30 health zones require antibiotics, facial cleanliness and environmental improvement interventions. Survey data suggest that trachoma is widespread: further surveys are warranted