Mass Treatment and the Effect on the Load ofChlamydia trachomatisInfection in a Trachoma-Hyperendemic Community

Abstract

Although most of the chlamydial load in this community resided in children, 10% of the high load resided in adults, most of whom did not have follicular trachoma and in whom the infection would be missed under treatment strategies that focus on clinical disease or children. These data support a mass treatment strategy for hyperendemic communities, at least as a first approach. In addition, treatment of children age < or =2 years should be reexamined, as >30% with high loads at baseline remained infected at 2 months, despite monitored treatment according to weight.

Single-Dose Azithromycin Prevents Trichiasis Recurrence Following Surgery

“…We expected the infection rate during the course of the study to be low in patients who received azithromycin. 14,15 However, we expected to see protection from reinfection with treatment of the household members, which was not apparent. Perhaps transmission to these older patients within household units is not strong in this Ethiopian setting (at least within the 1 year of observation).…”

“…Persons with both scarring and infection were at greatest risk of developing trichiasis 12 and C trachomatis is present in a significant proportion of adults, which may drive progression of trachoma. [13][14][15] Follow-up studies of surgical cases have found that postsurgical recurrence was highest in areas with greatest trachoma prevalence. 5,8 One study reported a higher rate of recurrence in surgical eyes with ocular C trachomatis infection compared with eyes without infection.…”

Effect of oral azithromycin in the treatment of chlamydial conjunctivitis

“…Third, in the treatment of trachoma worldwide, researches had found that rounds of mass treatment with single-dose azithromycin in trachoma-hyperendemic areas cannot eliminate trachoma or ocular C. trachomatis but can lower the incidence of infection in the long term. [22][23][24] In our study, there might also have been some patients with very high loads of C. trachomatis for whom a 2-week course of weekly azithromycin might have been insufficient to eradicate the infection. For these patients, augmented azithromycin may help eliminate the infection.…”

The Allee Effect and Elimination of Neglected Tropical Diseases: A Mathematical Modelling Study

“…This article discussed the proposal that there might be an Allee effect operating for trachoma, an idea based on the observation that the community prevalence level in a mass drug administration (MDA) field trial had held steady over a year after the administration of drug to the population (Solomon et al, 2004). This observation stood in contrast to the predictions of modelling and other posttreatment observational studies which found re-emergence of infection and disease to be the most likely outcome (Gambhir et al, 2010a(Gambhir et al, , 2009Liu et al, 2014;Burton et al, 2005;West et al, 2005). The proposed mechanisms for an Allee effect for trachoma include reductions in bacterial genotypic diversity leading to more effective immune responses from the host population, and a dose-dependent effect in which lower community prevalence leads to lower average chlamydial load and lower probability of transmission per contact.…”