TF and inclusion conjunctivitis: Although a direct comparison can not be made, in part because the aim for trachoma is not interruption of transmission, evidence from modelling suggests a suitable serological threshold for trachoma that equates to a TF prevalence of <5% in children aged 1–9 years, would be a seroprevalence (anti-Pgp3 antibodies) of 7.3% (95%CI: 6.5–8.3) [82].