Congratulations to the REACH Niger team on the publication of results derived from the multi-year, national-level AVENIR programme, in the prestigious journal Nature Medicine.
“Mass azithromycin distribution and antibiotic resistance in the gut and nasopharynx: a cluster-randomized trial” is the result of years of dedicated, painstaking fieldwork, and the mobilization of scientific and field teams to seek answers to some of the most pressing questions about mass drug administration (MDA) in the face of the growing threat of antimicrobial resistance (AMR).
A notable milestone
The publication of results in this prestigious journal is a notable milestone, both for the study team themselves and for the REACH Network of African-led research institutions, Ministries of Health, policy advocates, and implementation partners who work together to reduce preventable child mortality through evidence-based, equitable, and scalable solutions.
The AVENIR study team in Niger is made up of key personnel and an enduring partnership between the Centre de Recherche et Interventions en Santé Publique (CRISP), Birni N’Gaoure, Niger, the Programme National de Santé Oculaire, Niamey, Niger and the Doan Lab at the University of California, San Francisco, USA.
The study team’s article examines the implications for AMR rates of large-scale azithromycin MDA when used as a means to reduce childhood mortality in high-burden settings.
Balancing risks and gains
Conducted as part of a large cluster-randomized trial in Niger, the team’s research compares different age-targeting strategies (children aged 1-59 months, children aged 1-11 months, placebo) to assess resistance in the gut and nasopharyngeal microbiomes.
While prior trials have clearly demonstrated substantial mortality benefits from biannual azithromycin distribution, discussion more recently has increasingly focussed on the need to carefully balance these gains, and potential gains, with the risk of accelerating antibiotic resistance.
The AVENIR team’s findings indicate that repeated azithromycin MDA modestly increases macrolide resistance in the gut microbiome, particularly when treatment is extended to include older children, but shows no statistically significant increase in resistance in the nasopharynx.
Careful age-targeting
Targeting the infant-only group (1-11 months) appeared to produce less pronounced rates of resistance than treating the entire under-five population, implying that narrower targeting could preserve the mortality benefits of azithromycin MDA while mitigating some of the more alarming AMR risks.
In terms of antimicrobial stewardship, a key tenet of the Abuja Declaration on for Child Survival, the study provides valuable evidence on the resistance effects on the population level of preventive antibiotic use. The article’s authors also make the case for AMR surveillance systems to accompany scale-up of azithromycin MDA, so that longer-term or broader impacts may be detected.
Protecting treatments for the future
The study suggests that programme design – and age-targeting and the frequency of treatment in particular – can meaningfully influence resistance outcomes. This insight supports the “tailored”, country-owned, and locally-adaptive approach to azithromycin MDA which the REACH Network’s Co-chairs advocate so powerfully for.
The AVENIR team’s study is also another important contribution by REACH teams to the responsible stewardship of AMR in the context of azithromycin MDA, providing rigorous quantification of both the benefits and risks.
This exemplifies the REACH Network’s commitment to data-driven strategies that will protect both current and future generations from infectious disease threats, and the medicines we use to treat them.
