1. Serological Responses to Trachoma Antigens prior to the Start of Mass Drug Administration: Results from Population-Based Baseline Surveys, North Darfur, Sudan.
- Author
-
Sanders AM, Elshafie BE, Abdalla Z, Simmons C, Goodhew EB, Gonzalez TA, Nute AW, Mohammed A, Callahan EK, Martin DL, and Nash SD
- Subjects
- Humans, Sudan epidemiology, Child, Child, Preschool, Infant, Female, Adolescent, Male, Adult, Young Adult, Prevalence, Seroepidemiologic Studies, Middle Aged, Dried Blood Spot Testing, Trachoma epidemiology, Chlamydia trachomatis immunology, Antigens, Bacterial immunology, Mass Drug Administration, Antibodies, Bacterial blood
- Abstract
After years of programmatic inaccessibility, in 2019-2020 the Sudan Federal Ministry of Health Trachoma Control Program conducted population-based trachoma surveys in three localities (districts) in North Darfur state, Sudan. These baseline surveys were to determine the prevalence of trachomatous inflammation-follicular (TF) among children aged 1-9 years and to further use serological markers to understand the historical trachoma burden within this mass drug administration (MDA)-naive area. Trained and certified graders collected trachoma clinical data, and trained nurses collected dried blood spot (DBS) samples. The DBSs were assayed on a multiplex bead array for antibody responses to the Chlamydia trachomatis antigens Pgp3 and CT694. Across the three localities, 3,613 individuals aged 1-9 years and 3,542 individuals aged ≥15 years were examined for clinical signs, and 8,322 DBSs were collected. The prevalence of TF among children aged 1-9 years was endemic (≥5%) in two localities (El Seraif, 15.6%, and Saraf Omrah, 11.0%) and below the TF elimination threshold (<5%) in the third (Kotom, 1.4%). The Pgp3 seroprevalence among children aged 1-9 years was 34.1% in El Seraif, 35.0% in Saraf Omrah, and 11.0% in Kotom. Locality prevalence results were similar for Pgp3 and CT694. Seroprevalence increased with age in all three localities. Serological data collected within these surveys demonstrate that all three localities have had a long history of exposure to Chlamydia trachomatis and that two of the three localities require MDA to reach elimination as a public health problem threshold.
- Published
- 2024
- Full Text
- View/download PDF