Azithromycin did not prevent infant deaths when provided at routine healthcare visits in the West African country of Burkina Faso, a randomized controlled trial demonstrated.
Among infants who received a single oral dose of azithromycin at routine visits, 0.52% died before 6 months of age compared with 0.48% who received a placebo (HR 1.09, 95% CI 0.80-1.49, P=0.58), reported researchers led by Ali Sié, MD, PhD, of Centre de Recherche en Santé de Nouna in Burkina Faso.
Investigators found no differences in deaths between the two groups according to age, sex, or baseline weight.
"Individual-level treatment may not result in the same effects for prevention of death as have been observed with community-wide treatment," the authors wrote in the .
Researchers wanted to test whether providing azithromycin at routine well-infant visits would be just as effective as mass administration of azithromycin at reducing infant mortality, which has proven to be an effective strategy in some sub-Saharan African regions. But unlike providing azithromycin in healthcare settings, mass administration involves large-scale, community-wide distribution -- often conducted door-to-door -- requiring substantial resources and coordination, the authors pointed out.
Exactly how azithromycin reduces infant mortality is unknown, co-author Catherine Oldenburg, ScD, MPH, from the University of California San Francisco's Francis I. Proctor Foundation, told Ƶ. "Mass drug administration provides an indirect, herd-like effect, with benefit to individuals because others are treated," she said, most likely through reduction of pathogens in the entire community.
Emerging resistance to azithromycin remains an ongoing concern and was another motivation for examining an alternative to mass distribution, Oldenburg said.
"Presumably, individual dosing would lead to reduced antimicrobial resistance compared to community-wide treatment, but it does not prevent mortality and should not be considered as a strategy for azithromycin distribution to reduce mortality," she explained.
The showed that twice-yearly community-wide distribution of azithromycin in sub-Saharan Africa reduced all-cause mortality in infants ages 1 to 11 months of age by 25% and by 13.5% in children up to 59 months of age.
Based on findings from the MORDOR trial, the that mass drug administration of azithromycin be considered in children 1 to 11 months of age for prevention of childhood mortality in sub-Saharan African settings in which infant mortality is >60 per 1,000 live births or where mortality for children under 5 years is >80 per 1,000 live births (low quality evidence).
Some children enrolled in the current study lived in communities that were already receiving mass distribution of azithromycin. "We found no evidence of interaction between community distribution of azithromycin and individual treatment with azithromycin in infancy," the authors wrote.
Among infants who lived in communities with mass azithromycin treatment, 0.63% of those who were individually treated with azithromycin died compared with 0.56% of placebo recipients (HR 1.12, 95% CI 0.67-1.89). Among infants who lived in communities with no mass azithromycin treatment, 0.51% of infants receiving azithromycin died compared with 0.42% receiving placebo (HR 1.20, 95% CI 0.76-1.89).
The current study, , enrolled 32,877 infants ages 5 to 12 weeks of age in three areas of Burkina Faso to receive either a one-time dose of azithromycin (20 mg/kg) or placebo. The median age of infants enrolled in both groups was approximately 6.6-6.7 weeks of age, and 49% were girls. Very few children were lost to follow-up, and the vast majority of enrolled children were evaluated at 6 months of age. Incidence of adverse events were similar between the two groups.
By 6 months of age, 82 out of 16,416 infants in the azithromycin group and 75 out of 16,461 infants in the placebo group had died.
Researchers reported some limitations to the study. "We observed substantially lower mortality than projected," the authors noted, which possibly led to low statistical power. Investigators recruited infants in clinics and through community outreach, but they may have missed more vulnerable populations of children who had less access to routine healthcare and community events, they wrote.
Disclosures
The study was funded by the Bill and Melinda Gates Foundation.
Pfizer donated azithromycin and placebo used in the study.
Sié reported no disclosures. Oldenburg reported receiving funding from the Bill and Melinda Gates Foundation and the National Eye Institute. Two co-authors also reported receiving previous research grants from the Bill and Melinda Gates Foundation.
Primary Source
New England Journal of Medicine
Sié A, et al "Azithromycin during routine well-infant visits to prevent death" N Engl J Med 2024; DOI: 10.1056/NEJMoa2309495.