medRxiv : the preprint server for health sciences · 2026
Integrated serosurveillance to assess disease elimination in coastal Ecuador: onchocerciasis, yaws, and trachoma.
СтатьяПрепринтНазвание и аннотация: Перевод в очереди
Обработка статьи · этапы, ошибки и управление
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Ошибки и ограничения
История · было → стало
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Simbaña Vivanco Lesly, Torres Ayala Stuart, Walas Nikolina, Cooley Gretchen, Coleman Chabier, Goodhew E Brook, Martin Diana L, Burroughs Hadley, Kamau Everlyn, Calvopiña Manuel, Cevallos William, Coloma Josefina, Lee Gwenyth O, Trueba Gabriel, Eisenberg Joseph N S, Levy Karen, Arnold Benjamin F
Аннотация
BACKGROUND: Testing blood samples with multiplex bead assays can assess elimination and identify residual foci of transmission for multiple pathogens simultaneously. In Ecuador, onchocerciasis and yaws are presumed eliminated, and the status of trachoma is unknown. We assessed their elimination status by measuring IgG antibodies in children 6-24 months.
METHODS: In a birth cohort of 404 children measured between 2021-2024 in Esmeraldas province, Ecuador, we tested dried blood spots at ages 6, 9, 12, 18, and 24 months using a multiplex IgG assay that included antigens to Onchocerca volvulus (Ov16), Treponema pallidum (rp17, tmpa), and Chlamydia trachomatis (Pgp3, Ct694). We estimated seroprevalence and incident seroconversion rates across an urban-rural gradient.
RESULTS: Of 404 children enrolled, 370 contributed 1,606 samples. Seroprevalence was near zero for onchocerciasis (0.4%, 95% CI: 0.2% to 0.8%) and yaws (0.2%, 95% CI: 0.0% to 0.5%). Conversely, C. trachomatis Pgp3 seroprevalence increased along the urban-rural gradient from Esmeraldas city (3.4%, 95% CI: 1.8% to 5.8%) to remote, river-accessible rural villages (22.4%, 95% CI: 16.0% to 30.1%), and incident seroconversion was common in rural villages (16.1 per 100 child-years, 95% CI: 11.3 to 21.9).
CONCLUSIONS: Serologic surveillance found no evidence of O. volvulus or T. pallidum transmission, consistent with elimination. High Pgp3 seroconversion rates suggest ongoing C. trachomatis transmission in rural villages. Results highlight the value of integrated serologic surveillance and motivate in-depth trachoma surveillance in Esmeraldas.
METHODS: In a birth cohort of 404 children measured between 2021-2024 in Esmeraldas province, Ecuador, we tested dried blood spots at ages 6, 9, 12, 18, and 24 months using a multiplex IgG assay that included antigens to Onchocerca volvulus (Ov16), Treponema pallidum (rp17, tmpa), and Chlamydia trachomatis (Pgp3, Ct694). We estimated seroprevalence and incident seroconversion rates across an urban-rural gradient.
RESULTS: Of 404 children enrolled, 370 contributed 1,606 samples. Seroprevalence was near zero for onchocerciasis (0.4%, 95% CI: 0.2% to 0.8%) and yaws (0.2%, 95% CI: 0.0% to 0.5%). Conversely, C. trachomatis Pgp3 seroprevalence increased along the urban-rural gradient from Esmeraldas city (3.4%, 95% CI: 1.8% to 5.8%) to remote, river-accessible rural villages (22.4%, 95% CI: 16.0% to 30.1%), and incident seroconversion was common in rural villages (16.1 per 100 child-years, 95% CI: 11.3 to 21.9).
CONCLUSIONS: Serologic surveillance found no evidence of O. volvulus or T. pallidum transmission, consistent with elimination. High Pgp3 seroconversion rates suggest ongoing C. trachomatis transmission in rural villages. Results highlight the value of integrated serologic surveillance and motivate in-depth trachoma surveillance in Esmeraldas.