Comparison of annual versus twice-yearly mass azithromycin treatment for hyperendemic trachoma in Ethiopia: a cluster-randomised trial.

Background: In trachoma control programmes, azithromycin is distributed to treat the strains of chlamydia that cause ocular disease. We aimed to compare the effect of annual versus twice-yearly distribution of azithromycin on infection with these strains.

Methods: We did a cluster-randomised trial in 24 subdistricts in northern Ethiopia, which we randomly assigned to receive annual or twice-yearly treatment for all residents of all ages.

Risk factors for ocular chlamydia after three mass azithromycin distributions.

Background: An important component of the World Health Organization's comprehensive trachoma elimination strategy is the provision of repeated annual mass azithromycin distributions, which are directed at reducing the burden of ocular chlamydia. Knowledge of characteristics associated with infection after mass antibiotic treatments could allow trachoma programs to focus resources to those most likely to be infected with ocular chlamydia.

Methodology/principal Findings: We monitored 12 communities in rural Ethiopia that had received 3 annual mass azithromycin treatments as part of a cluster-randomized trial for trachoma.

Latrine promotion for trachoma: assessment of mortality from a cluster-randomized trial in Ethiopia.

Trachoma control strategies, including latrine construction and antibiotic distribution, are directed at reducing ocular chlamydia, but may have additional benefits. In a cluster-randomized clinical trial, 24 subkebeles (administrative geographic units) in Ethiopia were offered a single mass azithromycin treatment, and half were randomized to receive an intensive latrine promotion. At a follow-up census 26 months after the baseline treatment, 320 persons had died.

Adverse events after mass azithromycin treatments for trachoma in Ethiopia.

During a cluster-randomized clinical trial for trachoma in Ethiopia, two rounds of adverse event surveillance were performed in a random sample of communities after community-wide mass azithromycin treatment. The prevalence of any reported adverse event ranged from 4.9% to 7.

Efficacy of latrine promotion on emergence of infection with ocular Chlamydia trachomatis after mass antibiotic treatment: a cluster-randomized trial.

The World Health Organization (WHO) recommends environmental improvements such as latrine construction in the integrated trachoma control strategy, SAFE. We report a cluster-randomized trial assessing the effect of intensive latrine promotion on emergence of infection with ocular Chlamydia trachomatis after mass treatment with antibiotics.Twenty-four communities in Goncha Seso Enesie woreda, Amhara Regional State, Ethiopia, were enumerated, and a random selection of 60 children aged 0- 9 years in each was monitored for clinical signs of trachoma and ocular chlamydial infection at baseline, 12 and 24 months.

Childhood mortality in a cohort treated with mass azithromycin for trachoma.

Background: Mass azithromycin distributions are used to clear ocular strains of chlamydia that cause trachoma, but treatments may also affect respiratory infections, diarrhea, and malaria. Here, we monitor a large cohort in which almost 90% of individuals received azithromycin. We assess whether receiving treatment is associated with reduced all-cause and infectious childhood mortality.

The decline of pneumococcal resistance after cessation of mass antibiotic distributions for trachoma.

After 6 biannual mass distributions of oral azithromycin for trachoma in Ethiopian communities, 76.8% (95% confidence interval [CI], 66.3%-85.

Travel and implications for the elimination of trachoma in ethiopia.

Purpose: Trachoma is the leading infectious cause of blindness. The World Health Organization has set a goal of reducing the trachoma disease burden to a level where it is no longer a public health concern by the year 2020. Some investigators feel that local elimination of ocular chlamydia infection is possible, but little has been done to study the likelihood of reintroduction of infection from neighboring areas.

Clinical activity and polymerase chain reaction evidence of chlamydial infection after repeated mass antibiotic treatments for trachoma.

It is unclear how the prevalence of clinically active trachoma correlates with the prevalence of ocular chlamydial infection at the community level. In 24 villages from a cluster-randomized clinical trial of mass azithromycin distributions in Ethiopia, the correlation between the prevalence of clinical activity (on examination) and chlamydial infection (by polymerase chain reaction) was moderately strong before mass antibiotic treatments (Pearson's correlation coefficient r = 0.75, 95% confidence interval [CI] = 0.

Complete local elimination of infectious trachoma from severely affected communities after six biannual mass azithromycin distributions.

Objective: To determine whether infectious trachoma can be completely eliminated from severely affected villages.

Design: Cross-sectional survey of 2 villages previously enrolled and monitored over 42 months as part of a larger, group-randomized clinical trial.

Participants: A total of 758 individuals residing in 2 villages with high baseline trachoma prevalence, of a total population of 768 (98.

Effect of mass distribution of azithromycin for trachoma control on overall mortality in Ethiopian children: a randomized trial.

Context: Mass oral azithromycin distribution to affected communities is a cornerstone of the World Health Organization's trachoma elimination program. Antibiotics are provided to target the ocular strains of chlamydia that cause trachoma, but may also be efficacious against respiratory disease, diarrhea, and malaria--frequent causes of childhood mortality in trachoma-endemic areas.

Objective: To compare mortality rates of participants aged 1 to 9 years in treated communities with those in untreated communities.

Importance of coverage and endemicity on the return of infectious trachoma after a single mass antibiotic distribution.

Background: As part of the SAFE strategy, mass antibiotic treatments are useful in controlling the ocular strains of chlamydia that cause trachoma. The World Health Organization recommends treating at least 80% of individuals per community. However, the role of antibiotic coverage for trachoma control has been poorly characterized.

Lack of macrolide resistance in Chlamydia trachomatis after mass azithromycin distributions for trachoma.

We investigated antimicrobial drug resistance in ocular Chlamydia trachomatis 18 months after 4 biannual communitywide distributions of antimicrobial drugs in a region of Ethiopia where ocular strains of C. trachomatis are highly endemic. We found no significant differences in susceptibilities to azithromycin and doxycycline in 6 posttreatment and 4 pretreatment samples.

Assessment of herd protection against trachoma due to repeated mass antibiotic distributions: a cluster-randomised trial.

Background: Trachoma-control programmes distribute oral azithromycin to treat the ocular strains of chlamydia that cause the disease and to control infection. Theoretically, elimination of infection is feasible if untreated individuals receive an indirect protective effect from living in repeatedly treated communities, which is similar to herd protection in vaccine programmes. We assessed indirect protection against trachoma with mass azithromycin distributions.

Reduction and return of infectious trachoma in severely affected communities in Ethiopia.

Background: Antibiotics are a major tool in the WHO's trachoma control program. Even a single mass distribution reduces the prevalence of the ocular chlamydia that causes trachoma. Unfortunately, infection returns after a single treatment, at least in severely affected areas.

Detection of Chlamydia trachomatis ocular infection in trachoma-endemic communities by rRNA amplification.

Purpose: Trachoma remains the leading infectious cause of blindness worldwide. The World Health Organization (WHO) recommends mass antibiotic distributions in its strategy to eliminate blinding trachoma. To determine the most effective antibiotic treatment strategy, it is essential to have a diagnostic test that can correctly measure the true status of ocular Chlamydia trachomatis infection in individuals, particularly after treatment.

Comparison of annual and biannual mass antibiotic administration for elimination of infectious trachoma.

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.

Complete elimination is a difficult goal for trachoma programs in severely affected communities.

The World Health Organization has distributed millions of doses of azithromycin to control the ocular chlamydial infection that causes trachoma. Theoretically, a loftier goal of elimination is feasible. Here, we demonstrate that, although local elimination of infection in the most severely affected communities is difficult, it is possible with biannual antibiotic distributions.

A rationale for continuing mass antibiotic distributions for trachoma.

Background: The World Health Organization recommends periodic mass antibiotic distributions to reduce the ocular strains of chlamydia that cause trachoma, the world's leading cause of infectious blindness. Their stated goal is to control infection, not to completely eliminate it. A single mass distribution can dramatically reduce the prevalence of infection.

Comparison of an rRNA-based and DNA-based nucleic acid amplification test for the detection of Chlamydia trachomatis in trachoma.

Background/aim: The World Health Organisation (WHO) hopes to achieve global elimination of trachoma, still the leading cause of preventable blindness worldwide, in part through mass antibiotic treatment. DNA-based nucleic acid amplification tests (NAATs) are currently used to evaluate the success of treatment programmes by measuring the prevalence of C trachomatis infection. Some believe that newer ribosomal RNA (rRNA)-based tests may be much more sensitive since bacterial rRNA is present in amounts up to 10 000 times that of genomic DNA.

Effect of a single mass antibiotic distribution on the prevalence of infectious trachoma.

Context: The World Health Organization recommends mass antibiotic distributions in its strategy to eliminate blinding trachoma as a public health concern. Some hypothesize that a single distribution is sufficient to control the ocular strains of chlamydia that cause trachoma. Others believe infection will inevitably return and periodic treatments or other measures are essential.