Simplification and improvement of height-based azithromycin treatment for paediatric trachoma

Mass Azithromycin Distribution to Prevent Child Mortality in Burkina Faso: The CHAT Randomized Clinical Trial

Importance

Repeated mass distribution of azithromycin has been shown to reduce childhood mortality by 14% in sub-Saharan Africa. However, the estimated effect varied by location, suggesting that the intervention may not be effective in different geographical areas, time periods, or conditions.

Objective

To evaluate the efficacy of twice-yearly azithromycin to reduce mortality in children in the presence of seasonal malaria chemoprevention.

Design, Setting, and Participants

This cluster randomized placebo-controlled trial evaluating the efficacy of single-dose azithromycin for prevention of all-cause childhood mortality included 341 communities in the Nouna district in rural northwestern Burkina Faso. Participants were children aged 1 to 59 months living in the study communities.

Interventions

Communities were randomized in a 1:1 ratio to receive oral azithromycin or placebo distribution. Children aged 1 to 59 months were offered single-dose treatment twice yearly for 3 years (6 distributions) from August 2019 to February 2023.

Main Outcomes and Measures

The primary outcome was all-cause childhood mortality, measured during a twice-yearly enumerative census.

Results

A total of 34 399 children (mean [SD] age, 25.2 [18] months) in the azithromycin group and 33 847 children (mean [SD] age, 25.6 [18] months) in the placebo group were included. A mean (SD) of 90.1% (16.0%) of the censused children received the scheduled study drug in the azithromycin group and 89.8% (17.1%) received the scheduled study drug in the placebo group. In the azithromycin group, 498 deaths were recorded over 60 592 person-years (8.2 deaths/1000 person-years). In the placebo group, 588 deaths were recorded over 58 547 person-years (10.0 deaths/1000 person-years). The incidence rate ratio for mortality was 0.82 (95% CI, 0.67-1.02; P = .07) in the azithromycin group compared with the placebo group. The incidence rate ratio was 0.99 (95% CI, 0.72-1.36) in those aged 1 to 11 months, 0.92 (95% CI, 0.67-1.27) in those aged 12 to 23 months, and 0.73 (95% CI, 0.57-0.94) in those aged 24 to 59 months.

Conclusions and Relevance

Mortality in children (aged 1-59 months) was lower with biannual mass azithromycin distribution in a setting in which seasonal malaria chemoprevention was also being distributed, but the difference was not statistically significant. The study may have been underpowered to detect a clinically relevant difference.

Trial Registration

ClinicalTrials.gov Identifier: NCT03676764.

Targeted Mass Azithromycin Distribution for Trachoma: A Community-Randomized Trial (TANA II)

BACKGROUND

Current guidelines recommend annual community-wide mass administration of azithromycin for trachoma. Targeting treatments to those most likely to be infected could reduce the amount of unnecessary antibiotics distributed.

METHODS

In a cluster-randomized trial conducted from 1 November 2010 through 8 November 2013, 48 Ethiopian communities previously treated with annual mass azithromycin distributions for trachoma were randomized in equal numbers to (1) annual azithromycin distributions targeted to children aged 0-5 years, (2) annual azithromycin distributions targeted to households with a child aged 0-5 years found to have clinically active trachoma, (3) continued annual mass azithromycin distributions to the entire community, or (4) cessation of treatment. The primary outcome was the community prevalence of ocular chlamydia infection among children aged 0-9 years at month 36. Laboratory personnel were masked to treatment allocation.

RESULTS

The prevalence of ocular chlamydia infection among children aged 0-9 years increased from 4.3% (95% confidence interval [CI], .9%-8.6%) at baseline to 8.7% (95% CI, 4.2%-13.9%) at month 36 in the age-targeted arm, and from 2.8% (95% CI, .8%-5.3%) at baseline to 6.3% (95% CI, 2.9%-10.6%) at month 36 in the household-targeted arm. After adjusting for baseline chlamydia prevalence, the 36-month prevalence of ocular chlamydia was 2.4 percentage points greater in the age-targeted group (95% CI, -4.8% to 9.6%; P = .50; prespecified primary analysis). No adverse events were reported.

CONCLUSIONS

Targeting azithromycin treatment to preschool children was no different than targeting azithromycin to households with a child with clinically active trachoma. Neither approach reduced ocular chlamydia over the 3-year study.

CLINICAL TRIALS REGISTRATION

NCT01202331.

Simplified dosing of oral azithromycin for children 1-11 months old in child survival programmes: age-based and height-based dosing protocols

BACKGROUND

To facilitate mass distribution of azithromycin, trachoma control programmes use height instead of weight to determine dose for children 6 months to 15 years old. WHO has recommended azithromycin distribution to children 1-11 months old to reduce mortality in high mortality settings under carefully monitored conditions. Weight was used to determine dose in children 1-5 months old in studies of azithromycin distribution for child survival, but a simplified approach using age or height for all aged 1-11 months old could increase programme efficiency in real-world settings.

METHODS

This secondary analysis used data from two cluster randomised trials of azithromycin distribution for child mortality in Niger and Burkina Faso. An exhaustive search algorithm was developed to determine the optimal dose for different age groups, using tolerance limits of 10-20 mg/kg for children 1-2 months old and 15-30 mg/kg for children 3-11 months old. Height-based dosing was evaluated against the existing trachoma dosing pole and with a similar exhaustive search.

RESULTS

The optimal two-tiered age-based approach suggested a dose of 80 mg (2 mL) for children 1-2 months old and 160 mg (4 mL) for children 3-11 months old. Under this schedule, 89%-93% of children would have received doses within tolerance limits in both study populations. Accuracy was 93%-94% with a three-tiered approach, which resulted in doses of 80 mg (2 mL), 120 mg (3 mL) and 160 mg (4 mL) for children 1-2, 3-4 and 5-11 months old, respectively. For children 1-5 months old, the existing height pole would result in 70% of doses within tolerance limits. The optimisation identified height-based dosing options with 95% accuracy, although this would require changes to the existing dosing pole as well as additional training to measure infants lying flat.

CONCLUSIONS

Overall, an age-based approach with two age tiers resulted in high accuracy while considering both concerns about overdosing in this young population and simplicity of field operations.

Effect of Biannual Mass Azithromycin Distributions to Preschool-Aged Children on Trachoma Prevalence in Niger: A Cluster Randomized Clinical Trial

IMPORTANCE

Because transmission of ocular strains of Chlamydia trachomatis is greatest among preschool-aged children, limiting azithromycin distributions to this age group may conserve resources and result in less antimicrobial resistance, which is a potential advantage in areas with hypoendemic trachoma and limited resources.

OBJECTIVE

To determine the efficacy of mass azithromycin distributions to preschool-aged children as a strategy for trachoma elimination in areas with hypoendemic disease.

DESIGN, SETTING, AND PARTICIPANTS

In this cluster randomized clinical trial performed from November 23, 2014, until July 31, 2017, thirty rural communities in Niger were randomized at a 1:1 ratio to biannual mass distributions of either azithromycin or placebo to children aged 1 to 59 months. Participants and study personnel were masked to treatment allocation. Data analyses for trachoma outcomes were performed from October 19, 2021, through June 10, 2022.

INTERVENTIONS

Every 6 months, a single dose of either oral azithromycin (20 mg/kg using height-based approximation for children who could stand or weight calculation for small children) or oral placebo was provided to all children aged 1 to 59 months.

MAIN OUTCOMES AND MEASURES

Trachoma was a prespecified outcome of the trial, assessed as the community-level prevalence of trachomatous inflammation-follicular and trachomatous inflammation-intense through masked grading of conjunctival photographs from a random sample of 40 children per community each year during the 2-year study period. A secondary outcome was the seroprevalence of antibodies to C trachomatis antigens.

RESULTS

At baseline, 4726 children in 30 communities were included; 1695 children were enrolled in 15 azithromycin communities and 3031 children were enrolled in 15 placebo communities (mean [SD] proportions of boys, 51.8% [4.7%] vs 52.0% [4.2%]; mean [SD] age, 30.8 [2.8] vs 30.6 [2.6] months). The mean coverage of study drug for the 4 treatments was 79% (95% CI, 75%-83%) in the azithromycin group and 82% (95% CI, 79%-85%) in the placebo group. The mean prevalence of trachomatous inflammation-follicular at baseline was 1.9% (95% CI, 0.5%-3.5%) in the azithromycin group and 0.9% (95% CI, 0-1.9%) in the placebo group. At 24 months, trachomatous inflammation-follicular prevalence was 0.2% (95% CI, 0-0.5%) in the azithromycin group and 0.8% (95% CI, 0.2%-1.6%) in the placebo group (incidence rate ratio adjusted for baseline: 0.18 [95% CI, 0.01-1.20]; permutation P = .07).

CONCLUSIONS AND RELEVANCE

The findings of this trial do not show that biannual mass azithromycin distributions to preschool-aged children were more effective than placebo, although the underlying prevalence of trachoma was low. The sustained absence of trachoma even in the placebo group suggests that trachoma may have been eliminated as a public health problem in this part of Niger.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02048007.

Malaria positivity following a single oral dose of azithromycin among children in Burkina Faso: a randomized controlled trial

Background

Azithromycin is a broad-spectrum antibiotic that has moderate antimalarial activity and has been shown to reduce all-cause mortality when biannually administered to children under five in high mortality settings in sub-Saharan Africa. One potential mechanism for this observed reduction in mortality is via a reduction in malaria transmission.

Methods

We evaluated whether a single oral dose of azithromycin reduces malaria positivity by rapid diagnostic test (RDT). We conducted an individually randomized placebo-controlled trial in Burkina Faso during the high malaria transmission season in August 2020. Children aged 8 days to 59 months old were randomized to a single oral dose of azithromycin (20 mg/kg) or matching placebo. At baseline and 14 days following treatment, we administered a rapid diagnostic test (RDT) to detect Plasmodium falciparum and measured tympanic temperature for all children. Caregiver-reported adverse events and clinic visits were recorded at the day 14 visit.

Results

We enrolled 449 children with 221 randomized to azithromycin and 228 to placebo. The median age was 32 months and 48% were female. A total of 8% of children had a positive RDT for malaria at baseline and 11% had a fever (tympanic temperature ≥ 37.5 °C). In the azithromycin arm, 8% of children had a positive RDT for malaria at 14 days compared to 7% in the placebo arm (P = 0.65). Fifteen percent of children in the azithromycin arm had a fever ≥ 37.5 °C compared to 21% in the placebo arm (P = 0.12). Caregivers of children in the azithromycin group had lower odds of reporting fever as an adverse event compared to children in the placebo group (OR 0.41, 95% CI 0.18–0.96, P = 0.04). Caregiver-reported clinic visits were uncommon, and there were no observed differences between arms (P = 0.32).

Conclusions

We did not find evidence that a single oral dose of azithromycin reduced malaria positivity during the high transmission season. Caregiver-reported fever occurred less often in children receiving azithromycin compared to placebo, indicating that azithromycin may have some effect on non-malarial infections.

Trial registration Clinicaltrials.gov NCT04315272, registered 19/03/2020

Effect of Mass Azithromycin Distributions on Childhood Growth in Niger: A Cluster-Randomized Trial

IMPORTANCE

Mass azithromycin distributions may decrease childhood mortality, although the causal pathway is unclear. The potential for antibiotics to function as growth promoters may explain some of the mortality benefit.

OBJECTIVE

To investigate whether biannual mass azithromycin distributions are associated with increased childhood growth.

DESIGN, SETTING, AND PARTICIPANTS

This cluster-randomized trial was performed from December 2014 until March 2020 among 30 rural communities in Boboye and Loga departments in Niger, Africa, with populations from 200 to 2000 individuals. Communities were randomized in a 1:1 ratio to biannual mass distributions of azithromycin or placebo for children ages 1 to 59 months. Participants, field-workers, and study personnel were masked to treatment allocation. Height and weight changes from baseline to follow-up at 4 years were compared between groups. Data were analyzed from June through November 2021.

INTERVENTIONS

Participants received azithromycin at 20 mg/kg using height-based approximation or by weight for children unable to stand every 6 months at the participants' households. Placebo contained the vehicle of the azithromycin suspension.

MAIN OUTCOMES AND MEASURES

Longitudinal anthropometric assessments were performed on a random sample of children before the first treatment and then annually for 5 years. Height and weight were the prespecified primary outcomes.

RESULTS

Among 3936 children enrolled from 30 communities, baseline characteristics were similar between 1299 children in the azithromycin group and 2637 children in the placebo group (mean 48.2% [95% CI, 45.5% to 50.8%] girls vs 48.0% [95% CI, 45.7% to 50.3%] girls; mean age, 30.8 months [95% CI, 29.5 to 32.0 months] vs 30.6 months [95% CI, 29.2 to 31.6 months]). Baseline anthropometric assessments were performed among 2230 children, including 985 children in the azithromycin group and 1245 children in the placebo group, of whom follow-up measurements were available for 789 children (80.1%) and 1063 children (85.4%), respectively. At the prespecified 4-year follow-up visit, children in the azithromycin group gained a mean 6.7 cm (95% CI, 6.5 to 6.8 cm) in height and 1.7 kg (95% CI, 1.7 to 1.8 kg) in weight per year and children in the placebo group gained a mean 6.6 cm (95% CI, 6.4 to 6.7 cm) in height and 1.7 kg (95% CI, 1.7 to 1.8 kg) in weight per year. Height at 4 years was not statistically significantly different between groups when adjusted for baseline height (0.08 cm [95% CI, -0.12 to 0.28 cm] greater in the azithromycin group; P = .45), and neither was weight when adjusted for height and baseline weight (0.02 kg [95% CI, -0.10 to 0.06 kg] less in the azithromycin group; P = .64). However, among children in the shortest quartile of baseline height, azithromycin was associated with a 0.4 cm (95% CI, 0.1 to 0.7 cm) increase in height compared with placebo.

CONCLUSIONS AND RELEVANCE

This study did not find evidence of an association between mass azithromycin distributions and childhood growth, although subgroup analysis suggested some benefit for the shortest children. These findings suggest that the mortality benefit of mass azithromycin distributions is unlikely to be due solely to growth promotion.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02048007.

Effect of a single dose of oral azithromycin on malaria parasitaemia in children: a randomized controlled trial

Background

Azithromycin has recently been shown to reduce all-cause childhood mortality in sub-Saharan Africa. One potential mechanism of this effect is via the anti-malarial effect of azithromycin, which may help treat or prevent malaria infection. This study evaluated short- and longer-term effects of azithromycin on malaria outcomes in children.

Methods

Children aged 8 days to 59 months were randomized in a 1:1 fashion to a single oral dose of azithromycin (20 mg/kg) or matching placebo. Children were evaluated for malaria via thin and thick smear and rapid diagnostic test (for those with tympanic temperature ≥ 37.5 °C) at baseline and 14 days and 6 months after treatment. Malaria outcomes in children receiving azithromycin versus placebo were compared at each follow-up timepoint separately.

Results

Of 450 children enrolled, 230 were randomized to azithromycin and 220 to placebo. Children were a median of 26 months and 51% were female, and 17% were positive for malaria parasitaemia at baseline. There was no evidence of a difference in malaria parasitaemia at 14 days or 6 months after treatment. In the azithromycin arm, 20% of children were positive for parasitaemia at 14 days compared to 17% in the placebo arm (P = 0.43) and 7.6% vs. 5.6% in the azithromycin compared to placebo arms at 6 months (P = 0.47).

Conclusions

Azithromycin did not affect malaria outcomes in this study, possibly due to the individually randomized nature of the trial.

Trial registration This study is registered at clinicaltrials.gov (NCT03676751; registered 19 September 2018).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-021-03895-9.

Single-dose azithromycin for child growth in Burkina Faso: a randomized controlled trial

Background

In lower resource settings, previous randomized controlled trials have demonstrated evidence of increased weight gain following antibiotic administration in children with acute illness. We conducted an individually randomized trial to assess whether single dose azithromycin treatment causes weight gain in a general population sample of children in Burkina Faso.

Methods

Children aged 8 days to 59 months were enrolled in November 2019 and followed through June 2020 in Nouna Town, Burkina Faso. Participants were randomly assigned to a single oral dose of azithromycin (20 mg/kg) or matching placebo. Anthropometric measurements were collected at baseline and 14 days and 6 months after enrollment. The primary anthropometric outcome was weight gain velocity in g/kg/day from baseline to 14 days and 6 months in separate linear regression models.

Results

Of 450 enrolled children, 230 were randomly assigned to azithromycin and 220 to placebo. Median age was 26 months (IQR 16 to 38 months) and 51% were female. At 14 days, children in the azithromycin arm gained a mean difference of 0.9 g/kg/day (95% CI 0.2 to 1.6 g/kg/day, P = 0.01) more than children in the placebo arm. There was no difference in weight gain velocity in children receiving azithromycin compared to placebo at 6 months (mean difference 0.04 g/kg/day, 95% CI − 0.05 to 0.13 g/kg/day, P = 0.46). There were no significant differences in other anthropometric outcomes.

Conclusions

Transient increases in weight gain were observed after oral azithromycin treatment, which may provide short-term benefits.

Clinical trials registration

ClinicalTrials.gov NCT03676751. Registered 19/09/2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02601-7.

WASH Upgrades for Health in Amhara (WUHA): study protocol for a cluster-randomised trial in Ethiopia

INTRODUCTION

Facial hygiene promotion and environmental improvements are central components of the global trachoma elimination strategy despite a lack of experimental evidence supporting the effectiveness of water, sanitation and hygiene (WASH) measures for reducing trachoma transmission. The objective of the WUHA (WASH Upgrades for Health in Amhara) trial is to evaluate if a comprehensive water improvement and hygiene education programme reduces the prevalence of ocular chlamydia infection in rural Africa.

METHODS AND ANALYSIS

Forty study clusters, each of which had received at least annual mass azithromycin distributions for the 7 years prior to the start of the study, are randomised in a 1:1 ratio to the WASH intervention arm or a delayed WASH arm. The WASH package includes a community water point, community-based hygiene promotion workers, household wash stations, household WASH education books, household soap distribution and a primary school hygiene curriculum. Educational activities emphasise face-washing and latrine use. Mass antibiotic distributions are not provided during the first 3 years but are provided annually over the final 4 years of the trial. Annual monitoring visits are conducted in each community. The primary outcome is PCR evidence of ocular chlamydia infection among children aged 0-5 years, measured in a separate random sample of children annually over 7 years. A secondary outcome is improvement of the clinical signs of trachoma between the baseline and final study visits as assessed by conjunctival photography. Laboratory workers and photo-graders are masked to treatment allocation.

ETHICS AND DISSEMINATION

Study protocols have been approved by human subjects review boards at the University of California, San Francisco, Emory University, the Ethiopian Food and Drug Authority, and the Ethiopian Ministry of Innovation and Technology. A data safety and monitoring committee oversees the trial. Results will be disseminated through peer-reviewed publications and presentations.

TRIAL REGISTRATION NUMBER

(http://www.clinicaltrials.gov): NCT02754583; Pre-results.

Malaria Parasitemia and Nutritional Status during the Low Transmission Season in the Presence of Azithromycin Distribution among Preschool Children in Niger

The relationship between malaria and malnutrition is complicated, and existence of one may predispose or exacerbate the other. We evaluated the relationship between malaria parasitemia and nutritional status in children living in communities participating in a cluster-randomized trial of biannual azithromycin compared with placebo for prevention of childhood mortality. Data were collected during the low malaria transmission and low food insecurity season. Parasitemia was not associated with weight-for-height Z-score (24 months: P = 0.11 azithromycin communities, P = 0.75 placebo communities), weight-for-age Z-score (24 months: P = 0.83 azithromycin, P = 0.78 placebo), height-for-age Z-score (24 months: P = 0.30 azithromycin, P = 0.87 placebo), or mid-upper arm circumference (24 months: P = 0.12 azithromycin, P = 0.56 placebo). There was no statistically significant evidence of a difference in the relationship in communities receiving azithromycin or placebo. During the low transmission season, there was no evidence that malaria parasitemia and impaired nutritional status co-occur in children.

Cause-specific mortality of children younger than 5 years in communities receiving biannual mass azithromycin treatment in Niger: verbal autopsy results from a cluster-randomised controlled trial

Background

The Macrolides Oraux pour Réduire les Décès avec un Oeil sur la Résistance (MORDOR) trial found that biannual mass distribution of azithromycin to children younger than 5 years in Niger reduced the primary outcome of all-cause mortality by 18%. We aimed to determine the causes of mortality among deceased children using verbal autopsy.

Methods

In this 2-year cluster-randomised controlled trial, 594 community clusters in Niger were randomly allocated (1:1 ratio) to receive biannual mass distributions of either oral azithromycin (approximately 20 mg per kg of bodyweight) or placebo targeted to children aged 1–59 months. Participants, study investigators, and field workers were masked to treatment allocation. Between Nov 23, 2014, and July 31, 2017, 3615 child deaths were recorded by use of biannual house-to-house censuses, and verbal autopsies were done between May 26, 2015, and May 17, 2018, to identify cause of death. Cause-specific mortality, as assessed by verbal autopsy, was a prespecified secondary outcome. This trial is completed and is registered with ClinicalTrials.gov, NCT02047981.

Findings

Between Nov 23, 2014, and July 31, 2017, 303 communities (n=40 375 children at baseline) in Niger received mass azithromycin and 291 communities (n=35 747 children at baseline) received placebo. Treatment coverage was 90·3% (SD 10·6) in the azithromycin group and 90·4% (10·1) in the placebo group. No communities were lost to follow-up. In total, 1727 child deaths in the azithromycin group and 1888 child deaths in the placebo group were reported from the population censuses. Of these, the cause of death for 1566 (90·7%) children in the azithromycin group and 1735 (91·9%) children in the placebo group were ascertained by verbal autopsy interviews. In the azithromycin group, 437 (27·9%) deaths were due to malaria, 252 (16·1%) deaths were due to pneumonia, and 234 (14·9%) deaths were due to diarrhoea. In the placebo group, 493 (28·4%) deaths were due to malaria, 275 (15·9%) deaths were due to pneumonia, and 251 (14·5%) deaths were due to diarrhoea. Relative to communities that received placebo, child mortality in communities that received azithromycin was lower for malaria (incidence rate ratio 0·78, 95% CI 0·66–0·92; p=0·0029), dysentery (0·65, 0·44–0·94; p=0·025), meningitis (0·67, 0·46–0·97; p=0·036), and pneumonia (0·83, 0·68–1·00; p=0·051). The distribution of causes of death did not differ significantly between the two study groups (p=0·98).

Interpretation

Mass azithromycin distribution resulted in approximately a third fewer deaths in children aged 1–59 months due to meningitis and dysentery, and a fifth fewer deaths due to malaria and pneumonia. The lack of difference in the distribution of causes of death between the azithromycin and placebo groups could be attributable to the broad spectrum of azithromycin activity and the study setting, in which most childhood deaths were due to infections.

Funding

Bill & Melinda Gates Foundation.

Biannual mass azithromycin distributions and malaria parasitemia in pre-school children in Niger: A cluster-randomized, placebo-controlled trial

BACKGROUND

Mass azithromycin distributions have been shown to reduce mortality in preschool children, although the factors mediating this mortality reduction are not clear. This study was performed to determine whether mass distribution of azithromycin, which has modest antimalarial activity, reduces the community burden of malaria.

METHODS AND FINDINGS

In a cluster-randomized trial conducted from 23 November 2014 until 31 July 2017, 30 rural communities in Niger were randomized to 2 years of biannual mass distributions of either azithromycin (20 mg/kg oral suspension) or placebo to children aged 1 to 59 months. Participants, field staff, and investigators were masked to treatment allocation. The primary malaria outcome was the community prevalence of parasitemia on thick blood smear, assessed in a random sample of children from each community at study visits 12 and 24 months after randomization. Analyses were performed in an intention-to-treat fashion. At the baseline visit, a total of 1,695 children were enumerated in the 15 azithromycin communities, and 3,029 children were enumerated in the 15 placebo communities. No communities were lost to follow-up. The mean prevalence of malaria parasitemia at baseline was 8.9% (95% CI 5.1%-15.7%; 52 of 552 children across all communities) in the azithromycin-treated group and 6.7% (95% CI 4.0%-12.6%; 36 of 542 children across all communities) in the placebo-treated group. In the prespecified primary analysis, parasitemia was lower in the azithromycin-treated group at month 12 (mean prevalence 8.8%, 95% CI 5.1%-14.3%; 51 of 551 children across all communities) and month 24 (mean 3.5%, 95% CI 1.9%-5.5%; 21 of 567 children across all communities) than it was in the placebo-treated group at month 12 (mean 15.3%, 95% CI 10.8%-20.6%; 81 of 548 children across all communities) and month 24 (mean 4.8%, 95% CI 3.3%-6.4%; 28 of 592 children across all communities) (P = 0.02). Communities treated with azithromycin had approximately half the odds of parasitemia compared to those treated with placebo (odds ratio [OR] 0.54, 95% CI 0.30 to 0.97). Parasite density was lower in the azithromycin group than the placebo group at 12 and 24 months (square root-transformed outcome; density estimates were 7,540 parasites/μl lower [95% CI -350 to -12,550 parasites/μl; P = 0.02] at a mean parasite density of 17,000, as was observed in the placebo arm). No significant difference in hemoglobin was observed between the 2 treatment groups at 12 and 24 months (mean 0.34 g/dL higher in the azithromycin arm, 95% CI -0.06 to 0.75 g/dL; P = 0.10). No serious adverse events were reported in either group, and among children aged 1 to 5 months, the most commonly reported nonserious adverse events (i.e., diarrhea, vomiting, and rash) were less common in the azithromycin-treated communities. Limitations of the trial include the timing of the treatments and monitoring visits, both of which took place before the peak malaria season, as well as the uncertain generalizability to areas with different malaria transmission dynamics.

CONCLUSIONS

Mass azithromycin distributions were associated with a reduced prevalence of malaria parasitemia in this trial, suggesting one possible mechanism for the mortality benefit observed with this intervention.

TRIAL REGISTRATION

The trial was registered on ClinicalTrials.gov (NCT02048007).

A Longitudinal Analysis of Chlamydial Infection and Trachomatous Inflammation Following Mass Azithromycin Distribution

BACKGROUND

Mass azithromycin distributions are effective for clearing ocular strains of Chlamydia trachomatis, yet infection frequently returns in areas with hyperendemic trachoma. A better understanding of the factors associated with chlamydial reinfection could be helpful to plan trachoma elimination strategies.

METHODS

This was a prospective cohort study conducted in a trachoma-hyperendemic region of Ethiopia in 2003. As part of a larger cluster-randomized trial, 21 villages were treated with a single mass azithromycin distribution and all children 5 years and younger were monitored for ocular chlamydia and clinically active trachoma at baseline and at 2 and 6 months following the treatment.

RESULTS

In 20 villages with available data, azithromycin treatment coverage was 88.7% (95% confidence interval [CI] 85.7-91.8%). In total, 1005 children tested negative for ocular chlamydia at the 2-month visit, of whom 41 became infected by 6 months (1.0 incident chlamydia infections per 100 person-months, 95%CI 0.7-1.4). The presence of intense trachomatous inflammation (TI) at baseline was associated with incident infection at 6 months (incidence rate ratio 1.91, 95%CI 1.03-3.55). Ocular chlamydia infections clustered more within households than communities: (intraclass correlation coefficient 0.01 for communities and 0.29 for households six months posttreatment). Younger children were more likely to have persistent clinically active trachoma (P = 0.03).

CONCLUSIONS

More intensive antibiotic distributions may be warranted for younger children, for children with TI, and for households containing children with ocular chlamydia infections.

Mass azithromycin distribution for hyperendemic trachoma following a cluster-randomized trial: A continuation study of randomly reassigned subclusters (TANA II)

BACKGROUND

The World Health Organization recommends annual mass azithromycin administration in communities with at least 10% prevalence of trachomatous inflammation-follicular (TF) in children, with further treatment depending on reassessment after 3-5 years. However, the effect of stopping mass azithromycin distribution after multiple rounds of treatment is not well understood. Here, we report the results of a cluster-randomized trial where communities that had received 4 years of treatments were then randomized to continuation or discontinuation of treatment.

METHODS AND FINDINGS

In all, 48 communities with 3,938 children aged 0-9 years at baseline in northern Ethiopia had received 4 years of annual or twice yearly mass azithromycin distribution as part of the TANA I trial. We randomized these communities to either continuation or discontinuation of treatment. Individuals in the communities in the continuation arm were offered either annual or twice yearly distribution of a single directly observed dose of oral azithromycin. The primary outcome was community prevalence of ocular chlamydial infection in a random sample of children aged 0-9 years, 36 months after baseline. We also assessed the change from baseline to 36 months in ocular chlamydia prevalence within each arm. We compared 36-month ocular chlamydia prevalence in communities randomized to continuation versus discontinuation in a model adjusting for baseline ocular chlamydia prevalence. A secondary prespecified analysis assessed the rate of change over time in ocular chlamydia prevalence between arms. In the continuation arm, mean antibiotic coverage was greater than 90% at all time points. In the discontinuation arm, the mean prevalence of infection in children aged 0-9 years increased from 8.3% (95% CI 4.2% to 12.4%) at 0 months to 14.7% (95% CI 8.7% to 20.8%, P = 0.04) at 36 months. Ocular chlamydia prevalence in communities where mass azithromycin distribution was continued was 7.2% (95% CI 3.3% to 11.0%) at baseline and 6.6% (95% CI 1.1% to 12.0%, P = 0.64) at 36 months. The 36-month prevalence of ocular chlamydia was significantly lower in communities continuing treatment compared with those discontinuing treatment (P = 0.03). Limitations of the study include uncertain generalizability outside of trachoma hyperendemic regions.

CONCLUSIONS

In this study, ocular chlamydia infection rebounded after 4 years of periodic mass azithromycin distribution. Continued distributions did not completely eliminate infection in all communities or meet WHO control goals, although they did prevent resurgence.

TRIAL REGISTRATION

This study was prospectively registered at clinicaltrials.gov (clinicaltrials.gov NCT01202331).

Mass Azithromycin and Malaria Parasitemia in Niger: Results from a Community-Randomized Trial

Studies designed to determine the effects of mass administration of azithromycin on trachoma have suggested that mass azithromycin distributions may also reduce the prevalence of malaria. These studies have typically examined the impact of a small number of treatments over short durations. In this prespecified substudy of a cluster-randomized trial for trachoma, we compared malaria parasitemia prevalence in 24 communities in Niger randomized to receive either annual or biannual mass azithromycin distributions over 3 years. The 12 communities randomized to annual azithromycin received three treatments during the high-transmission season, and the 12 communities randomized to biannual azithromycin received a total of six treatments: three during the high-transmission season and three during the low-transmission season. Blood samples were taken to assess malariometric indices among children in all study communities at a single time point during the high-transmission season after 3 years of the intervention. No significant differences were identified in malaria parasitemia, parasite density, or hemoglobin concentration between the annual and biannual treatment arms. When compared with annual mass azithromycin alone, additional mass azithromycin distributions given during the low-transmission season did not significantly reduce the subsequent prevalence of malaria parasitemia or parasite density after 3 years, as measured during the high-transmission season.

Impact of mass azithromycin distribution on malaria parasitemia during the low-transmission season in Niger: a cluster-randomized trial

We assessed the effect of mass azithromycin treatment on malaria parasitemia in a trachoma trial in Niger. Twenty-four study communities received treatment during the wet, high-transmission season. Twelve of the 24 communities were randomized to receive an additional treatment during the dry, low-transmission season. Outcome measurements were conducted at the community-level in children < 1-72 months of age in May-June 2011. Parasitemia was higher in the 12 once-treated communities (29.8%, 95% confidence interval [CI] = 21.5-40.0%) than in the 12 twice-treated communities (19.5%, 95% CI = 13.0-26.5%, P = 0.03). Parasite density was higher in once-treated communities (354 parasites/μL, 95% CI = 117-528 parasites/μL) than in twice-treated communities (74 parasites/μL, 95% CI = 41-202 parasites/μL, P = 0.03). Mass distribution of azithromycin reduced malaria parasitemia 4-5 months after the intervention. The results suggest that drugs with antimalaria activity can have long-lasting impacts on malaria during periods of low transmission.

Trachoma and antibiotic use: the 'A' in SAFE

Trachoma, a chronic conjunctivitis caused by Chlamydia trachomatis, is the leading infectious cause of blindness worldwide. In recognition of this public health problem, the World Health Assembly has targeted the year 2020 to eliminate blinding trachoma, and a multifaceted strategy (SAFE) is recommended, including antibiotics for treatment of infection. Trachoma is a disease of entire communities, and the pool of infection resides largely in preschool age children. Thus, for endemic communities, mass treatment with antibiotics annually for at least 3-5 years is carried out. The antibiotics used, the effectiveness of this approach, and the challenges of antibiotic treatment of communities are discussed, concluding with a view towards the elimination of trachoma in the future.

Diagnostic characteristics of tests for ocular Chlamydia after mass azithromycin distributions

PURPOSE

Although trachoma control programs frequently use the World Health Organization (WHO) simplified grading system for trachoma to monitor the clinical response after repeated mass azithromycin treatments, the programmatic relevance of this evaluation after multiple rounds of antibiotic treatments is unclear.

METHODS

Three rounds of annual mass azithromycin were distributed to 12 villages in Ethiopia. Twelve months after the third treatment, children were assessed for follicular trachomatous inflammation (TF) and intense trachomatous inflammation (TI) using the WHO simplified grading system and for ocular chlamydial infection using DNA-based and RNA-based tests. Test characteristics for predicting chlamydial infection were computed assuming a chlamydial RNA-based gold standard. As a secondary analysis, test characteristics were also assessed using a latent class analysis.

RESULTS

The prevalence of RNA evidence of ocular chlamydia was 7.1% (95% confidence interval [CI], 2.7-17.4). A DNA-based test and TF had sensitivities of 61.0% (95% CI, 47.1-73.3) and 65.9% (95% CI, 41.6-83.9), specificities of 100% (95% CI, 99.3-100) and 67.5% (95% CI, 61.0-73.5), and positive predictive values of 100% (95% CI, 86.3-100) and 13.4% (95% CI, 5.5-29.3) compared with an RNA-based gold standard. The latent class analysis confirmed that the RNA-based test was a reasonable choice for a gold standard, with a sensitivity of 100% (95% CI, 67.1-100) and specificity of 99.6% (95% CI, 98.1-100).

CONCLUSIONS

Basing treatment decisions after mass azithromycin distributions on the WHO simplified grading system will maximize the treatment of infected persons compared with a DNA-based test but will also result in more uninfected persons being treated. The RNA-based test was considerably more sensitive, and almost equivalently specific, compared with a DNA-based test. (ClinicalTrials.gov number, NCT00322972.).

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.

METHODS

As part of a clinical trial for trachoma, a census was conducted in 24 communities in rural Ethiopia. All individuals ≥1 year of age were eligible for single-dose oral azithromycin, although antibiotic coverage was not universal. A follow-up census was performed 26 months after treatment to estimate all-cause mortality among children 1-5 years of age, and verbal autopsies were performed to identify infectious mortality.

RESULTS

The cohort included 35,052 individuals ≥1 year of age and 5507 children 1-5 years of age, of whom 4914 received a dose of azithromycin. All-cause mortality was significantly lower among those 1-5-year-old children who received azithromycin (odds ratio [OR]=0.35 [95% confidence interval {CI}, 0.17-0.74]), as was infectious mortality (OR=0.20 [95% CI, 0.07-0.58]). When individuals were compared only with members of the same household, azithromycin treatment was still associated with reduced all-cause mortality in children 1-5 years of age (OR=0.40 [95% CI, 0.16-0.96]), although this relationship was not statistically significant for infectious mortality (OR=0.35 [95% CI, 0.10-1.28]).

CONCLUSIONS

This study demonstrated an association between mass oral azithromycin treatment and reduced all-cause and infectious childhood mortality. This relationship could not be attributed to bias at the level of the household. Mass azithromycin distributions may have benefits unrelated to trachoma.