Comparison of Annual and Biannual Mass Antibiotic Administration for Elimination of Infectious Trachoma

Abstract

Context Treatment recommendations assume that repeated mass antibiotic distributions can control, but not eradicate or even locally eliminate, the ocular strains of chlamydia that cause trachoma. Elimination may be an important end point because of concern that infection will return to communities that have lost immunity to chlamydia after antibiotics are discontinued. Objective To determine whether biannual treatment can eliminate ocular chlamydial infection from preschool children and to compare results with the World Health Organization-recommended annual treatment. Design, Setting, and Participants A cluster-randomized clinical trial of biannual vs annual mass azithromycin administrations to all residents of 16 rural villages in the Gurage Zone, Ethiopia, from March 2003 to April 2005. Interventions At scheduled treatments, all individuals aged 1 year or older were offered a single dose of oral azithromycin either annually or biannually. Main Outcome Measure Village prevalence of ocular chlamydial infection and presence of elimination at 24 months in preschool children determined by polymerase chain reaction, correcting for baseline prevalence. Antibiotic treatments were performed after sample collections. Results Overall, 14 897 of 16 403 eligible individuals (90.8%) received their scheduled treatment. In the villages in which residents were treated annually, the prevalence of infection in preschool children was reduced from a mean of 42.6% (range, 14.7%-56.4%) to 6.8% (range, 0.0%-22.0%) at 24 months. In the villages in which residents were treated biannually, infection was reduced from 31.6% pretreatment (range, 6.1%-48.6%) to 0.9% (range, 0.0%-4.8%) at 24 months. Biannual treatment was associated with a lower prevalence at 24 months (P=.03, adjusting for baseline prevalence). At 24 months, no infection could be identified in 6 of 8 of those treated biannually and in 1 of 8 of those treated annually (P=.049, adjusting for baseline prevalence). Conclusion Local elimination of ocular chlamydial infection appears feasible even in the most severely affected areas, although it may require biannual mass antibiotic distributions at a high coverage level.

Association of Conjunctival Bacterial Infection and Female Sex in Cicatricial Trachoma

“…Villages came from different treatment arms of the trial, but were similar in that none of the villages had received mass azithromycin within the preceding 6 months. Of the nine villages, four had received a single dose of mass azithromycin 1 year prior, 10 three had received mass azithromycin 1 year prior and 6 months prior to this study, 11 and two had received no mass azithromycin treatment.…”

“…We performed a clinical trial of different mass azithromycin treatment strategies in an area of Ethiopia with highly prevalent trachoma. 10,11 During this study, we collected swabs of persons with cicatricial signs of trachoma, to determine the microbiologic profile of conjunctival organisms in persons with trichiasis.…”

Estimating Community Prevalence of OcularChlamydia trachomatisInfection using Pooled Polymerase Chain Reaction Testing

“…The use of pooled estimates has been effective in such settings as the TEF study and Trachoma Amelioration in Northern Amhara clinical trial, where pooled estimates were used as primary outcomes. 12,13,16,17,19 Unlike other pooling PCR protocols, we do not require unpooling and retesting specimens at the individual level. In this paper we provided recommendations for pooling that are applicable in a broader setting, and show that the imprecision introduced by pooling can be kept within acceptable limits by simply choosing a small enough pool size.…”

Multiplex 5′ Nuclease-Quantitative PCR for Diagnosis of Relapsing Fever in a Large Tanzanian Cohort

“…We sought to identify incidents of symptomatic and asymptomatic relapsing fever as an ancillary study to that of mass treatment with azithromycin for trachoma (Partnership for the Rapid Elimination of Trachoma [PRETϩ]). In the parent study, four villages in the Kongwa district in the central Dodoma region of Tanzania were selected for WHO-recommended single-dose mass treatment with azithromycin (20 mg/kg of body weight, up to 1 g) for highly prevalent (Ն10%) active (trachomatous follicular or intense) trachoma (17,21,25). Within villages, 130 households per village (intervention group) were randomly selected.…”