Infection with Chlamydia trachomatis after mass treatment of a trachoma hyperendemic community in Tanzania: a longitudinal study

Complete Elimination is a Difficult Goal for Trachoma Programs in Severely Affected Communities

“…In regions where infection has been monitored, azithromycin distribution has reduced the prevalence of infection with ocular strains of chlamydia. However, if infection is not eliminated by treatment, it has been shown to return, at least in communities of hyperendemicity [4,8,9]. In our study, we found that complete elimination was difficult.…”

“…In villages with low rates of infection, у1 treatments have come close to eliminating infection [5][6][7]. In areas of hyperendemicity, if infection is not eliminated from a community, it can clearly return, even if a decrease to a low rate of infection is achieved [4,8,9]. To date, no study has demonstrated that infection can be locally eliminated from all members of a severely affected community.…”

“…Possibilities include incomplete coverage, ineffective treatment, and reintroduction of infection from outside the community; all have been hypothesized [4,6,9]. Molecular epidemiological studies that use the genetic heterogeneity of chlamydia to track cases have not resolved the issue [10].…”

Design and Baseline Data of a Randomized Trial to Evaluate Coverage and Frequency of Mass Treatment with Azithromycin: The Partnership for Rapid Elimination of Trachoma (PRET) in Tanzania and The Gambia

“…While high population mass treatment coverage (> 80%) may eliminate infection in mesoendemic communities, 7,8 these same efforts in hyperendemic communities appear to result in a decline in active trachoma and infection but not to 0%, even after multiple years of treatment. [9][10][11] Moreover, there appears to be a lag time, sometimes years, after infection declines or disappears before the clinical signs of trachoma start to disappear. 12 Consequently, a onesize-fits-all approach to mass treatment for trachoma can unintentionally promote an inefficient allocation of limited resources for trachoma prevalence surveys when not indicated or continued mass treatment when infection has disappeared.…”

Elimination of trachoma: are we in danger of being blinded by the randomised controlled trial?

“…The results of a single mass treatment in a village hyperendemic to trachoma in the Kongwa district, Tanzania, showed a reduction in the prevalence of chlamydial infection from 57% to 12% 2 months after treatment. 4 Similarly, in Rombo district, Tanzania, where trachoma is endemic a sustained reduction in the prevalence of chlamydial infection was achieved after a single mass distribution of azithromycin; however, in Rombo, all children with active disease at 6, 12 and 18 months were offered topical tetracycline treatment. 5 In addition both studies reported considerable reductions in the prevalence of clinical disease.…”