Safety of azithromycin in infants under six months of age in Niger: A community randomized trial

Feasibility and acceptability of integrating mass distribution of azithromycin to children 1-11 months into a trachoma mass drug administration campaign to reduce child mortality in Côte d'Ivoire

Evidence suggests that bi-annual mass drug administration (MDA) of single-dose azithromycin to 1-11 month-old children reduces child mortality in high child-mortality settings. Several countries conduct annual MDAs to distribute azithromycin to individuals ages 6 months and older to prevent trachoma infection. This study examined the feasibility and acceptability of reaching 1-11 months-old children during a trachoma MDA in Côte d'Ivoire by extending azithromycin distribution to infants 1-5 months old during the campaign. In November 2020, the study piloted single-dose azithromycin for 1-5 month-olds during a trachoma MDA in one health district. Monitoring data included the number of children reached and occurrences of adverse drug reactions. Feasibility, the extent to which the target population received the intervention (coverage), was assessed through a population-based, household survey with parents/caregivers of eligible children conducted after the MDA. Acceptability was explored through in-depth interviews (IDIs) with parents/caregivers of eligible children, focus group discussions (FGDs) with community drug distributors (CDDs), and IDIs with their supervisors. CDD FGDs and supervisor IDIs also documented implementation challenges and recommendations for scale-up. 1,735 1-5 month-olds received azithromycin during the pilot activity (estimated population coverage of 90.2%). Adverse drug reactions were reported for 1% (n = 18) infants; all were mild and self-limited. The post-MDA coverage survey interviewed 267 parents/caregivers; survey-based intervention coverage was 95.4% of 1-5 month-olds. Qualitative data revealed high intervention acceptability among parents, CDDs, and supervisors. Implementation challenges included the need to weigh babies to calculate dosage for 1-5 month-olds and the need to obtain written informed consent from parents to provide the drug to 1-5 month-olds. CDDs also indicated the need for more information on azithromycin and possible side effects during training. Delivering azithromycin to younger infants appears acceptable to parents and implementers; >90% coverage indicates feasibility to integrate into a trachoma MDA. (Clinicaltrials.gov ID number: NCT04617626).

Azithromycin during Routine Well-Infant Visits to Prevent Death

BACKGROUND

Mass distribution of azithromycin to children 1 to 59 months of age has been shown to reduce childhood all-cause mortality in some sub-Saharan African regions, with the largest reduction seen among infants younger than 12 months of age. Whether the administration of azithromycin at routine health care visits for infants would be effective in preventing death is unclear.

METHODS

We conducted a randomized, placebo-controlled trial of a single dose of azithromycin (20 mg per kilogram of body weight) as compared with placebo, administered during infancy (5 to 12 weeks of age). The primary end point was death before 6 months of age. Infants were recruited at routine vaccination or other well-child visits in clinics and through community outreach in three regions of Burkina Faso. Vital status was assessed at 6 months of age.

RESULTS

Of the 32,877 infants enrolled from September 2019 through October 2022, a total of 16,416 infants were randomly assigned to azithromycin and 16,461 to placebo. Eighty-two infants in the azithromycin group and 75 infants in the placebo group died before 6 months of age (hazard ratio, 1.09; 95% confidence interval [CI], 0.80 to 1.49; P = 0.58); the absolute difference in mortality was 0.04 percentage points (95% CI, -0.10 to 0.21). There was no evidence of an effect of azithromycin on mortality in any of the prespecified subgroups, including subgroups defined according to age, sex, and baseline weight, and no evidence of a difference between the two trial groups in the incidence of adverse events.

CONCLUSIONS

In this trial conducted in Burkina Faso, we found that administration of azithromycin to infants through the existing health care system did not prevent death. (Funded by the Bill and Melinda Gates Foundation; CHAT ClinicalTrials.gov number, NCT03676764.).

Cost and community acceptability of enhanced antibiotic distribution approaches for trachoma in the Republic of South Sudan: enhancing the A in SAFE (ETAS) study protocol

BACKGROUND

The World Health Organization targeted trachoma for global elimination as a public health problem by 2030. Reaching elimination thresholds by the year 2030 in the Republic of South Sudan will be a considerable challenge, as the country currently has many counties considered hyper-endemic (> 30% trachomatous inflammation-follicular [TF]) that have yet to receive interventions. Evidence from randomized trials, modeling, and population-based surveys suggests that enhancements may be needed to the standard-of-care annual mass drug administration (MDA) to reach elimination thresholds in a timely manner within highly endemic areas. We describe a protocol for a study to determine the cost and community acceptability of enhanced antibiotic strategies for trachoma in South Sudan.

METHODS

The Enhancing the A in SAFE (ETAS) study is a community randomized intervention costing and community acceptability study. Following a population-based trachoma prevalence survey in 1 county, 30 communities will be randomized 1:1 to receive 1 of 2 enhanced MDA interventions, with the remaining communities receiving standard-of-care annual MDA. The first intervention strategy will consist of a community-wide MDA followed by 2 rounds of targeted treatment to children ages 6 months to 9 years, 2 weeks and 4 weeks after the community MDA. The second strategy will consist of a community-wide biannual MDA approximately 6 to 8 months apart. The costing analysis will use a payer perspective and identify the total cost of the enhanced interventions and annual MDA. Community acceptability will be assessed through MDA coverage monitoring and mixed-methods research involving community stakeholders. A second trachoma-specific survey will be conducted 12 months following the original survey.

DISCUSSION

ETAS has received ethical clearance and is expected to be conducted between 2022 and 2023. Results will be shared through subsequent manuscripts. The study's results will provide information to trachoma programs on whether enhanced interventions are affordable and acceptable to communities. These results will further help in the design of future trachoma-specific antibiotic efficacy trials. Enhanced MDA approaches could help countries recover from delays caused by conflict or humanitarian emergencies and could also assist countries such as South Sudan in reaching trachoma elimination as a public health problem by 2030.

TRIAL REGISTRATION

This trial was registered on December 1^st, 2022 (clinicaltrails.org: NCT05634759).

Azithromycin distribution and childhood mortality in compliance-related subgroups in Niger: complier average causal effect and spillovers in a cluster-randomized, placebo-controlled trial

BACKGROUND

Biannual azithromycin distribution to children 1-59 months old reduced all-cause mortality by 18% [incidence rate ratio (IRR) 0.82, 95% confidence interval (CI): 0.74, 0.90] in an intention-to-treat analysis of a randomized controlled trial in Niger. Estimation of the effect in compliance-related subgroups can support decision making around implementation of this intervention in programmatic settings.

METHODS

The cluster-randomized, placebo-controlled design of the original trial enabled unbiased estimation of the effect of azithromycin on mortality rates in two subgroups: (i) treated children (complier average causal effect analysis); and (ii) untreated children (spillover effect analysis), using negative binomial regression.

RESULTS

In Niger, 594 eligible communities were randomized to biannual azithromycin or placebo distribution and were followed from December 2014 to August 2017, with a mean treatment coverage of 90% [standard deviation (SD) 10%] in both arms. Subgroup analyses included 2581 deaths among treated children and 245 deaths among untreated children. Among treated children, the incidence rate ratio comparing mortality in azithromycin communities to placebo communities was 0.80 (95% CI: 0.72, 0.88), with mortality rates (deaths per 1000 person-years at risk) of 16.6 in azithromycin communities and 20.9 in placebo communities. Among untreated children, the incidence rate ratio was 0.91 (95% CI: 0.69, 1.21), with rates of 33.6 in azithromycin communities and 34.4 in placebo communities.

CONCLUSIONS

As expected, this analysis suggested similar efficacy among treated children compared with the intention-to-treat analysis. Though the results were consistent with a small spillover benefit to untreated children, this trial was underpowered to detect spillovers.

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.

Secondary Effects from Mass Azithromycin Administration: A Systematic Review and Meta-analysis

The effects of azithromycin mass drug administration (MDA) on trachoma and yaws have been addressed. However, the secondary effects of azithromycin MDA remain unclear. This study aimed to explore the secondary effects of azithromycin MDA. PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov were searched from conception to January 5, 2022. Studies on secondary effects of azithromycin MDA were included. A total of 34 studies were included. Six of them reported on child mortality, 10 on malaria, and 20 on general morbidity and condition. Azithromycin MDA reduced child mortality, and quarterly MDA may be most beneficial for reducing child mortality. The effect of azithromycin MDA on malaria was weak. No association was observed between azithromycin MDA and malaria parasitemia (rate ratio: 0.71, 95% confidence interval: 0.43-1.15). Azithromycin MDA was associated with a lower risk of respiratory tract infections and diarrhea. Additionally, it was associated with a lower risk of fever, vomiting, and headache. The carriage of pathogenic organisms such as Streptococcus pneumoniae and gut Campylobacter species was reduced. However, these secondary effects of azithromycin MDA appeared to last only a few weeks. Moreover, no association was observed between azithromycin MDA and nutritional improvement in children. In conclusion, azithromycin MDA had favorable secondary effects on child mortality and morbidity. However, the effects were short term.

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.

Mass drug administration of antibacterials: weighing the evidence regarding benefits and risks

Background

Mass drug administration (MDA) is a strategy to improve health at the population level through widespread delivery of medicine in a community. We surveyed the literature to summarize the benefits and potential risks associated with MDA of antibacterials, focusing predominantly on azithromycin as it has the greatest evidence base.

Main body

High-quality evidence from randomized controlled trials (RCTs) indicate that MDA-azithromycin is effective in reducing the prevalence of infection due to yaws and trachoma. In addition, RCTs suggest that MDA-azithromycin reduces under-five mortality in certain low-resource settings that have high childhood mortality rates at baseline. This reduction in mortality appears to be sustained over time with twice-yearly MDA-azithromycin, with the greatest effect observed in children < 1 year of age. In addition, observational data suggest that infections such as skin and soft tissue infections, rheumatic heart disease, acute respiratory illness, diarrheal illness, and malaria may all be treated by azithromycin and thus incidentally impacted by MDA-azithromycin. However, the mechanism by which MDA-azithromycin reduces childhood mortality remains unclear. Verbal autopsies performed in MDA-azithromycin childhood mortality studies have produced conflicting data and are underpowered to answer this question. In addition to benefits, there are several important risks associated with MDA-azithromycin. Direct adverse effects potentially resulting from MDA-azithromycin include gastrointestinal side effects, idiopathic hypertrophic pyloric stenosis, cardiovascular side effects, and increase in chronic diseases such as asthma and obesity. Antibacterial resistance is also a risk associated with MDA-azithromycin and has been reported for both gram-positive and enteric organisms. Further, there is the risk for cross-resistance with other antibacterial agents, especially clindamycin.

Conclusions

Evidence shows that MDA-azithromycin programs may be beneficial for reducing trachoma, yaws, and mortality in children < 5 years of age in certain under-resourced settings. However, there are significant potential risks that need to be considered when deciding how, when, and where to implement these programs. Robust systems to monitor benefits as well as adverse effects and antibacterial resistance are warranted in communities where MDA-azithromycin programs are implemented.

Graphical Abstract

Trachoma

Trachoma is a neglected tropical disease caused by infection with conjunctival strains of Chlamydia trachomatis. It can result in blindness. Pathophysiologically, trachoma is a disease complex composed of two linked chronic processes: a recurrent, generally subclinical infectious-inflammatory disease that mostly affects children, and a non-communicable, cicatricial and, owing to trichiasis, eventually blinding disease that supervenes in some individuals later in life. At least 150 infection episodes over an individual's lifetime are needed to precipitate trichiasis; thus, opportunity exists for a just global health system to intervene to prevent trachomatous blindness. Trachoma is found at highest prevalence in the poorest communities of low-income countries, particularly in sub-Saharan Africa; in June 2021, 1.8 million people worldwide were going blind from the disease. Blindness attributable to trachoma can appear in communities many years after conjunctival C. trachomatis transmission has waned or ceased; therefore, the two linked disease processes require distinct clinical and public health responses. Surgery is offered to individuals with trichiasis and antibiotic mass drug administration and interventions to stimulate facial cleanliness and environmental improvement are designed to reduce infection prevalence and transmission. Together, these interventions comprise the SAFE strategy, which is achieving considerable success. Although much work remains, a continuing public health problem from trachoma in the year 2030 will be difficult for the world to excuse.

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

Comparing Azithromycin to Amoxicillin in the Management of Uncomplicated Severe Acute Malnutrition in Burkina Faso: A Pilot Randomized Trial

Azithromycin is a promising alternative to amoxicillin in the management of uncomplicated severe acute malnutrition (SAM) as it can be administered as a single dose and has efficacy against several pathogens causing infectious disease and mortality in children under 5. In this pilot trial, we aimed to establish the feasibility of a larger randomized controlled trial and provide preliminary evidence comparing the effect of azithromycin to amoxicillin on weight gain in children with uncomplicated SAM. We enrolled children 6-59 months old with uncomplicated SAM at six healthcare centers in Burkina Faso. Participants were randomized to a single dose of azithromycin or a 7-day course of amoxicillin and followed weekly until nutritional recovery and again at 8 weeks. Apart from antibiotics, participants received standard of care, which includes ready-to-use therapeutic food. Primary feasibility outcomes included enrollment potential, refusals, and loss to follow-up. The primary clinical outcome was weight gain (g/kg/day) over 8 weeks. Outcome assessors were masked. Between June and October 2020, 312 children were screened, 301 were enrolled with zero refusals, and 282 (93.6%) completed the 8-week visit. Average weight gain was 2.5 g/kg/day (standard deviation [SD] 2.0) in the azithromycin group and 2.6 (SD 1.7) in the amoxicillin group (mean difference -0.1, 95% CI -0.5 to 0.3, P = 0.63). Fewer adverse events were reported in the azithromycin group (risk ratio 0.50, 95% CI 0.31-0.82, P = 0.006). With strong enrollment and follow-up, a fully powered trial in this setting is feasible.

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.

Safety of azithromycin in pediatric infectious diseases: a clinical systematic review and meta-analysis

BACKGROUND

Azithromycin is a second-generation macrolide antibiotic which can be used in the treatment of diseases caused by sensitive bacterial infections. This article aimed to investigate the safety of azithromycin in the treatment of infectious diseases in children by meta-analysis.

METHODS

PubMed, Embase, and Cochrane were selected as the search database platforms. Randomized controlled trials (RCTs) published after 2010 were searched using the following keywords: "azithromycin", "children", "adverse event", "intravenous event", and "oral". Included studies were all clinical trials of azithromycin in the treatment of pediatric diseases. After inclusion/exclusion criteria screening and bias risk assessment, data were extracted from the included studies. RevMan 5.3.5 software was used for statistical analysis to obtain both forest and funnel plots.

RESULTS

A total of nine articles involving 3,597 pediatric patients were included in this study. The results of meta-analysis showed that the nine articles exhibited statistical heterogeneity (I²=70%; P=0.001), and thus, a random-effects model was used. The obtained statistic was [odds ratio (OR) =0.65; 95% confidence interval (CI): (0.43, 0.97)], the statistical effect value was Z=2.10, P=0.04, and the difference was statistically significant. After excluding one article, the remaining eight articles showed homogeneity (I²=12%; P=0.34). So, using fixed-effects model analysis, the statistic was [OR =0.79; 95% CI: (0.67, 0.94)], and the effect size value was Z=2.73, P=0.006.

DISCUSSION

Compared with other antibiotics, the clinical safety of azithromycin is relatively good, but care should be taken when the dosage is high in treating some disease.

Privacy-first health research with federated learning

Privacy protection is paramount in conducting health research. However, studies often rely on data stored in a centralized repository, where analysis is done with full access to the sensitive underlying content. Recent advances in federated learning enable building complex machine-learned models that are trained in a distributed fashion. These techniques facilitate the calculation of research study endpoints such that private data never leaves a given device or healthcare system. We show-on a diverse set of single and multi-site health studies-that federated models can achieve similar accuracy, precision, and generalizability, and lead to the same interpretation as standard centralized statistical models while achieving considerably stronger privacy protections and without significantly raising computational costs. This work is the first to apply modern and general federated learning methods that explicitly incorporate differential privacy to clinical and epidemiological research-across a spectrum of units of federation, model architectures, complexity of learning tasks and diseases. As a result, it enables health research participants to remain in control of their data and still contribute to advancing science-aspects that used to be at odds with each other.

Azithromycin Reduction to Reach Elimination of Trachoma (ARRET): study protocol for a cluster randomized trial of stopping mass azithromycin distribution for trachoma

Background

The World Health Organization (WHO) recommends annual mass azithromycin distribution until districts drop below 5% prevalence of trachomatous inflammation—follicular (TF). Districts with very low TF prevalence may have little or no transmission of the ocular strains of Chlamydia trachomatis that cause trachoma, and additional rounds of mass azithromycin distribution may not be useful. Here, we describe the protocol for a randomized controlled trial designed to evaluate whether mass azithromycin distribution can be stopped prior to the current WHO guidelines.

Methods

The Azithromycin Reduction to Reach Elimination of Trachoma (ARRET) study is a 1:1 community randomized non-inferiority trial designed to evaluate whether mass azithromycin distribution can be stopped in districts with baseline prevalence of TF under 20%. Communities in Maradi, Niger are randomized after baseline assessment either to continued annual mass azithromycin distribution or stopping annual azithromycin distribution over a 3-year period. We will compare the prevalence of ocular C. trachomatis (primary outcome), TF and other clinical signs of trachoma, and serologic markers of trachoma after 3 years. We hypothesize that stopping annual azithromycin distribution will be non-inferior to continued annual azithromycin distributions for all markers of trachoma prevalence and transmission.

Discussion

The results of this trial are anticipated to provide potentially guideline-changing evidence for when mass azithromycin distributions can be stopped in low TF prevalence areas.

Trial registration number

This study is registered at clinicaltrials.gov (NCT04185402). Registered December 4, 2019; prospectively registered pre-results.

Adverse Events and Clinic Visits following a Single Dose of Oral Azithromycin among Preschool Children: A Randomized Placebo-Controlled Trial

Biannual mass azithromycin distribution reduces all-cause child mortality in some settings in sub-Saharan Africa; however, adverse events and short-term infectious outcomes following treatment have not been well characterized. Children aged 0–59 months were recruited in Nouna Town, Burkina Faso, and randomized 1:1 to a single directly observed oral 20 mg/kg dose of azithromycin or placebo. At 14 days after treatment, caregivers were interviewed about adverse event symptoms their child experienced since treatment and if they had sought health care for their child. All children had tympanic temperature measured at the 14-day visit. We compared adverse events and clinic visits using logistic regression models between azithromycin- and placebo-controlled children. Of 450 children enrolled, 230 were randomized to azithromycin and 220 to placebo. On average, children were aged 28 months, and 50.9% were female. Caregivers of 20% of children reported that their child experienced at least one adverse event, with no significant difference between study arms (19.9% azithromycin; 20.0% placebo, logistic regression P = 0.96). Vomiting was more often reported by caregivers of azithromycin-treated children than by those of placebo-treated children (7.2% azithromycin, 1.9% placebo, logistic regression P = 0.01). There were no significant differences in other adverse events or clinic visits. Adverse events following a single oral dose of azithromycin in preschool children were rare and mild. Azithromycin administration appears safe in this population.

Biannual azithromycin distribution and child mortality among malnourished children: A subgroup analysis of the MORDOR cluster-randomized trial in Niger

BACKGROUND

Biannual azithromycin distribution has been shown to reduce child mortality as well as increase antimicrobial resistance. Targeting distributions to vulnerable subgroups such as malnourished children is one approach to reaching those at the highest risk of mortality while limiting selection for resistance. The objective of this analysis was to assess whether the effect of azithromycin on mortality differs by nutritional status.

METHODS AND FINDINGS

A large simple trial randomized communities in Niger to receive biannual distributions of azithromycin or placebo to children 1-59 months old over a 2-year timeframe. In exploratory subgroup analyses, the effect of azithromycin distribution on child mortality was assessed for underweight subgroups using weight-for-age Z-score (WAZ) thresholds of -2 and -3. Modification of the effect of azithromycin on mortality by underweight status was examined on the additive and multiplicative scale. Between December 2014 and August 2017, 27,222 children 1-11 months of age from 593 communities had weight measured at their first study visit. Overall, the average age among included children was 4.7 months (interquartile range [IQR] 3-6), 49.5% were female, 23% had a WAZ < -2, and 10% had a WAZ < -3. This analysis included 523 deaths in communities assigned to azithromycin and 661 deaths in communities assigned to placebo. The mortality rate was lower in communities assigned to azithromycin than placebo overall, with larger reductions among children with lower WAZ: -12.6 deaths per 1,000 person-years (95% CI -18.5 to -6.9, P < 0.001) overall, -17.0 (95% CI -28.0 to -7.0, P = 0.001) among children with WAZ < -2, and -25.6 (95% CI -42.6 to -9.6, P = 0.003) among children with WAZ < -3. No statistically significant evidence of effect modification was demonstrated by WAZ subgroup on either the additive or multiplicative scale (WAZ < -2, additive: 95% CI -6.4 to 16.8, P = 0.34; WAZ < -2, multiplicative: 95% CI 0.8 to 1.4, P = 0.50, WAZ < -3, additive: 95% CI -2.2 to 31.1, P = 0.14; WAZ < -3, multiplicative: 95% CI 0.9 to 1.7, P = 0.26). The estimated number of deaths averted with azithromycin was 388 (95% CI 214 to 574) overall, 116 (95% CI 48 to 192) among children with WAZ < -2, and 76 (95% CI 27 to 127) among children with WAZ < -3. Limitations include the availability of a single weight measurement on only the youngest children and the lack of power to detect small effect sizes with this rare outcome. Despite the trial's large size, formal tests for effect modification did not reach statistical significance at the 95% confidence level.

CONCLUSIONS

Although mortality rates were higher in the underweight subgroups, this study was unable to demonstrate that nutritional status modified the effect of biannual azithromycin distribution on mortality. Even if the effect were greater among underweight children, a nontargeted intervention would result in the greatest absolute number of deaths averted.

TRIAL REGISTRATION

The MORDOR trial is registered at clinicaltrials.gov NCT02047981.

Clinical comparison of five anti-chlamydial antibiotics in koalas (Phascolarctos cinereus)

Chlamydiosis is the most significant infectious disease of koalas (Phascolarctos cinereus). It is primarily a systemic sexually transmitted disease caused by Chlamydia pecorum and was responsible for 46% of the 2348 koala admissions to Australia Zoo Wildlife Hospital between 2013 and 2017. Treatment of chlamydiosis in koalas is complicated by three major factors. Firstly, koalas rely on bacterial fermentation of their high fibre diet making antibiotic therapy a risk. Secondly, they possess efficient metabolic pathways for the excretion of plant toxins and potentially of therapeutic agents. Thirdly, wild koalas, often present to rehabilitation facilities with chronic and severe disease. Traditional anti-chlamydial antibiotics used in other species may cause fatal dysbiosis in koalas or be excreted before they can be effective. We compared five anti-chlamydial antibiotics, azithromycin, chloramphenicol, doxycycline, enrofloxacin and florfenicol, which were used to treat 86 wild koalas with chlamydiosis presented to Australia Zoo Wildlife Hospital under consistent conditions of nutrition, housing, husbandry and climate. Response to treatment was assessed by recovery from clinical signs, and clearance of detectable Chlamydia via quantitative PCR. Doxycycline was the most effective anti-chlamydial antibiotic of the five, producing a 97% cure rate, followed by chloramphenicol (81%), enrofloxacin (75%), florfenicol (66%) and azithromycin (25%). The long-acting injectable preparation of doxycycline was well tolerated by koalas when administered via the subcutaneous route, and the weekly dosing requirement is a major advantage when treating wild animals. These findings indicate that doxycycline is the current drug of choice for the treatment of chlamydiosis in koalas, with chloramphenicol being the best alternative.

Safety of azithromycin in pediatrics: a systematic review and meta-analysis

Purpose

To evaluate the toxicity of azithromycin in neonates, infants, and children.

Methods

A systematic review was performed for relevant studies using Medline (Ovid), PubMed, Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, and International Pharmaceutical Abstracts. We calculated the pooled incidence of adverse drug reactions (ADRs) associated with azithromycin based on prospective studies (RCTs and prospective cohort studies) and analyzed the risk difference (RD) of ADRs between azithromycin and placebo or other antibiotics using meta-analysis of RCTs.

Results

We included 133 studies with 4243 ADRs reported in 197,675 neonates, infants, and children who received azithromycin. The safety of azithromycin as MDA in pediatrics was poorly monitored. The main ADRs were diarrhea and vomiting. In prospective non-MDA studies, the most common toxicity was gastrointestinal ADRs (938/1967; 47.7%). The most serious toxicities were cardiac (prolonged QT or irregular heart beat) and idiopathic hypertrophic pyloric stenosis (IHPS). Compared with placebo, azithromycin did not show increased risk ADRs based on RCTs (risk difference − 0.17 to 0.07). The incidence of QT prolonged was higher in the medium-dosage group (10–30 mg/kg/day) than that of low-dosage group (≤ 10 mg/kg/day) (82.0% vs 1.2%).

Conclusion

The safety of azithromycin as MDA needs further evaluation. The most common ADRs are diarrhea and vomiting. The risk of the most serious uncommon ADRs (cardiac-prolonged QT and IHPS) is unknown.

Electronic supplementary material

The online version of this article (10.1007/s00228-020-02956-3) contains supplementary material, which is available to authorized users.

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.

A double-masked placebo-controlled trial of azithromycin to prevent child mortality in Burkina Faso, West Africa: Community Health with Azithromycin Trial (CHAT) study protocol

Background

Biannual, mass azithromycin distribution has previously been shown to reduce all-cause child mortality in sub-Saharan Africa. Subgroup analysis suggested that the strongest effects were in the youngest children, leading to the hypothesis that targeting younger age groups might be an effective strategy to prevent mortality. We present the methods of two randomized controlled trials designed to evaluate mass and targeted azithromycin distribution for the prevention of child mortality in Burkina Faso, West Africa.

Methods/design

The Child Health with Azithromycin Treatment (CHAT) study consists of two nested, randomized controlled trials. In the first, communities are randomized in a 1:1 fashion to biannual, mass azithromycin distribution or placebo. The primary outcome is under-5 all-cause mortality measured at the community level. In the second, children attending primary healthcare facilities during the first 5–12 weeks of life for a healthy child visit (e.g., for vaccination) are randomized in a 1:1 fashion to a single orally administered dose of azithromycin or placebo. The primary outcome is all-cause mortality measured at 6 months of age. The trial commenced enrollment in August 2019.

Discussion

This study is expected to provide evidence on two health systems delivery approaches (mass and targeted treatment) for azithromycin to prevent all-cause child mortality. The results will inform global and national policies related to azithromycin for the prevention of child mortality.

Trial registration

ClinicalTrials.gov, ID: NCT03676764. Registered on 19 September 2018; prospectively registered pre results.

Neonatal azithromycin administration to prevent infant mortality: study protocol for a randomised controlled trial

INTRODUCTION

Biannual mass azithromycin distribution to children aged 1-59 months has been shown to reduce all-cause mortality. Children under 28 days of age were not treated in studies evaluating mass azithromycin distribution for child mortality due to concerns related to infantile hypertrophic pyloric stenosis (IHPS). Here, we report the design of a randomised controlled trial to evaluate the efficacy and safety of administration of a single dose of oral azithromycin during the neonatal period.

METHODS AND ANALYSIS

The Nouveaux-nés et Azithromycine: une Innovation dans le Traitement des Enfants (NAITRE) study is a double-masked randomised placebo-controlled trial designed to evaluate the efficacy of a single dose of azithromycin (20 mg/kg) for the prevention of child mortality. Newborns (n=21 712) aged 8-27 days weighing at least 2500 g are 1:1 randomised to a single, directly observed, oral dose of azithromycin or matching placebo. Participants are followed weekly for 3 weeks after treatment to screen for adverse events, including IHPS. The primary outcome is all-cause mortality at the 6-month study visit.

ETHICS AND DISSEMINATION

This study was approved by the Institutional Review Boards at the University of California, San Francisco in San Francisco, USA (Protocol #18-25027) and the Comité National d'Ethique pour la Recherche in Ouagadougou, Burkina Faso (Protocol #2018-10-123). The findings of this trial will be presented at local, regional and international meetings and published in open access peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03682653; Pre-results.

Longer-Term Assessment of Azithromycin for Reducing Childhood Mortality in Africa

BACKGROUND

The MORDOR I trial (Macrolides Oraux pour Réduire les Décès avec un Oeil sur la Résistance) showed that in Niger, mass administration of azithromycin twice a year for 2 years resulted in 18% lower postneonatal childhood mortality than administration of placebo. Whether this benefit could increase with each administration or wane owing to antibiotic resistance was unknown.

METHODS

In the Niger component of the MORDOR I trial, we randomly assigned 594 communities to four twice-yearly distributions of either azithromycin or placebo to children 1 to 59 months of age. In MORDOR II, all these communities received two additional open-label azithromycin distributions. All-cause mortality was assessed twice yearly by census workers who were unaware of participants' original assignments.

RESULTS

In the MORDOR II trial, the mean (±SD) azithromycin coverage was 91.3±7.2% in the communities that received twice-yearly azithromycin for the first time (i.e., had received placebo for 2 years in MORDOR I) and 92.0±6.6% in communities that received azithromycin for the third year (i.e., had received azithromycin for 2 years in MORDOR I). In MORDOR II, mortality was 24.0 per 1000 person-years (95% confidence interval [CI], 22.1 to 26.3) in communities that had originally received placebo in the first year and 23.3 per 1000 person-years (95% CI, 21.4 to 25.5) in those that had originally received azithromycin in the first year, with no significant difference between groups (P = 0.55). In communities that had originally received placebo, mortality decreased by 13.3% (95% CI, 5.8 to 20.2) when the communities received azithromycin (P = 0.007). In communities that had originally received azithromycin and continued receiving it for an additional year, the difference in mortality between the third year and the first 2 years was not significant (-3.6%; 95% CI, -12.3 to 4.5; P = 0.50).

CONCLUSIONS

We found no evidence that the effect of mass administration of azithromycin on childhood mortality in Niger waned in the third year of treatment. Childhood mortality decreased when communities that had originally received placebo received azithromycin. (Funded by the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT02047981.).

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).