| Contributors: |
Pinsent, Amy; Solomon, Anthony W.; Bailey, Robin L.; Bid, Rhiannon; Cama, Anaseini; Dean, Deborah; Goodhew, Brook; Gwyn, Sarah E.; Jack, Kelvin R.; Kandel, Ram Prasad; Kama, Mike; Massae, Patrick; Macleod, Colin; Mabey, David C. W.; Migchelsen, Stephanie; Müller, Andreas; Sandi, Frank; Sokana, Oliver; Taoaba, Raebwebwe; Tekeraoi, Rabebe; Martin, Diana L.; White, Michael. T. |
| Description: |
Robust surveillance methods are needed for trachoma control and recrudescence monitoring, but existing methods have limitations. Here, we analyse data from nine trachoma-endemic populations and provide operational thresholds for interpretation of serological data in low-transmission and post-elimination settings. Analyses with sero-catalytic and antibody acquisition models provide insights into transmission history within each population. To accurately estimate sero-conversion rates (SCR) for trachoma in populations with high-seroprevalence in adults, the model accounts for secondary exposure to Chlamydia trachomatis due to urogenital infection. We estimate the population half-life of sero-reversion for anti-Pgp3 antibodies to be 26 (95% credible interval (CrI): 21-34) years. We show SCRs below 0.015 (95% confidence interval (CI): 0.0-0.049) per year correspond to a prevalence of trachomatous inflammation-follicular below 5%, the current threshold for elimination of active trachoma as a public health problem. As global trachoma prevalence declines, we may need cross-sectional serological survey data to inform programmatic decisions. ; 2018 ; 2018-12-21T00:00:00Z ; 001/World Health Organization/International ; 30575720 ; PMC6303365 ; 6789 |