@article {1381, title = {Prolonged mass azithromycin distributions and macrolide resistance determinants among preschool children in Niger: A sub-study of a cluster-randomized trial (MORDOR).}, journal = {PLoS Med}, volume = {21}, year = {2024}, month = {2024 May}, pages = {e1004386}, abstract = {

BACKGROUND: Randomized controlled trials found that twice-yearly mass azithromycin administration (MDA) reduces childhood mortality, presumably by reducing infection burden. World Health Organization (WHO) issued conditional guidelines for mass azithromycin administration in high-mortality settings in sub-Saharan Africa given concerns for antibiotic resistance. While prolonged twice-yearly MDA has been shown to increase antibiotic resistance in small randomized controlled trials, the objective of this study was to determine if macrolide and non-macrolide resistance in the gut increases with the duration of azithromycin MDA in a larger setting.

METHODS AND FINDINGS: The Macrolide Oraux pour R{\'e}duire les D{\'e}c{\`e}s avec un Oeil sur la R{\'e}sistance (MORDOR) study was conducted in Niger from December 2014 to June 2020. It was a cluster-randomized trial of azithromycin (A) versus placebo (P) aimed at evaluating childhood mortality. This is a sub-study in the MORDOR trial to track changes in antibiotic resistance after prolonged azithromycin MDA. A total of 594 communities were eligible. Children 1 to 59 months in 163 randomly chosen communities were eligible to receive treatment and included in resistance monitoring. Participants, staff, and investigators were masked to treatment allocation. At the conclusion of MORDOR Phase I, by design, all communities received an additional year of twice-yearly azithromycin treatments (Phase II). Thus, at the conclusion of Phase II, the treatment history (1 letter per 6-month period) for the participating communities was either (PP-PP-AA) or (AA-AA-AA). In Phase III, participating communities were then re-randomized to receive either another 3 rounds of azithromycin or placebo, thus resulting in 4 treatment histories: Group 1 (AA-AA-AA-AA-A, N = 51), Group 2 (PP-PP-AA-AA-A, N = 40), Group 3 (AA-AA-AA-PP-P, N = 27), and Group 4 (PP-PP-AA-PP-P, N = 32). Rectal swabs from each child (N = 5,340) were obtained 6 months after the last treatment. Each child contributed 1 rectal swab and these were pooled at the community level, processed for DNA-seq, and analyzed for genetic resistance determinants. The primary prespecified outcome was macrolide resistance determinants in the gut. Secondary outcomes were resistance to beta-lactams and other antibiotic classes. Communities recently randomized to azithromycin (groups 1 and 2) had significantly more macrolide resistance determinants than those recently randomized to placebo (groups 3 and 4) (fold change 2.18, 95\% CI 1.5 to 3.51, Punadj \< 0.001). However, there was no significant increase in macrolide resistance in communities treated 4.5 years (group 1) compared to just the most recent 2.5 years (group 2) (fold change 0.80, 95\% CI 0.50 to 1.00, Padj = 0.010), or between communities that had been treated for 3 years in the past (group 3) versus just 1 year in the past (group 4) (fold change 1.00, 95\% CI 0.78 to 2.35, Padj = 0.52). We also found no significant differences for beta-lactams or other antibiotic classes. The main limitations of our study were the absence of phenotypic characterization of resistance, no complete placebo arm, and no monitoring outside of Niger limiting generalizability.

CONCLUSIONS: In this study, we observed that mass azithromycin distribution for childhood mortality among preschool children in Niger increased macrolide resistance determinants in the gut but that resistance may plateau after 2 to 3 years of treatment. Co-selection to other classes needs to be monitored.

TRIAL REGISTRATION: NCT02047981 https://classic.clinicaltrials.gov/ct2/show/NCT02047981.

}, keywords = {Anti-Bacterial Agents, Azithromycin, Child Mortality, Child, Preschool, Drug Resistance, Bacterial, Female, Humans, Infant, Macrolides, Male, Mass Drug Administration, Niger}, issn = {1549-1676}, doi = {10.1371/journal.pmed.1004386}, author = {Arzika, Ahmed M and Abdou, Amza and Maliki, Ramatou and Beido, Nassirou and Kadri, Boubacar and Harouna, Abdoul N and Galo, Abdoul N and Alio, Mankara K and Lebas, Elodie and Oldenburg, Catherine E and O{\textquoteright}Brien, Kieran S and Chen, Cindi and Zhong, Lina and Zhou, Zhaoxia and Yan, Daisy and Hinterwirth, Armin and Keenan, Jeremy D and Porco, Travis C and Lietman, Thomas M and Doan, Thuy} } @article {911, title = {Age-based targeting of biannual azithromycin distribution for child survival in Niger: an adaptive cluster-randomized trial protocol (AVENIR).}, journal = {BMC Public Health}, volume = {21}, year = {2021}, month = {2021 04 29}, pages = {822}, abstract = {

BACKGROUND: Biannual distribution of azithromycin to children 1-59 months old reduced mortality by 14\% in a cluster-randomized trial. The World Health Organization has proposed targeting this intervention to the subgroup of children 1-11 months old to reduce selection for antimicrobial resistance. Here, we describe a trial designed to determine the impact of age-based targeting of biannual azithromycin on mortality and antimicrobial resistance.

METHODS: AVENIR is a cluster-randomized, placebo-controlled, double-masked, response-adaptive large simple trial in Niger. During the 2.5-year study period, 3350 communities are targeted for enrollment. In the first year, communities in the Dosso region will be randomized 1:1:1 to 1) azithromycin 1-11: biannual azithromycin to children 1-11 months old with placebo to children 12-59 months old, 2) azithromycin 1-59: biannual azithromycin to children 1-59 months old, or 3) placebo: biannual placebo to children 1-59 months old. Regions enrolled after the first year will be randomized with an updated allocation based on the probability of mortality in children 1-59 months in each arm during the preceding study period. A biannual door-to-door census will be conducted to enumerate the population, distribute azithromycin and placebo, and monitor vital status. Primary mortality outcomes are defined as all-cause mortality rate (deaths per 1000 person-years) after 2.5 years from the first enrollment in 1) children 1-59 months old comparing the azithromycin 1-59 and placebo arms, 2) children 1-11 months old comparing the azithromycin 1-11 and placebo arm, and 3) children 12-59 months in the azithromycin 1-11 and azithromycin 1-59 arms. In the Dosso region, 50 communities from each arm will be followed to monitor antimicrobial resistance. Primary resistance outcomes will be assessed after 2 years of distributions and include 1) prevalence of genetic determinants of macrolide resistance in nasopharyngeal samples from children 1-59 months old, and 2) load of genetic determinants of macrolide resistance in rectal samples from children 1-59 months old.

DISCUSSION: As high-mortality settings consider this intervention, the results of this trial will provide evidence to support programmatic and policy decision-making on age-based strategies for azithromycin distribution to promote child survival.

TRIAL REGISTRATION: This trial was registered on January 13, 2020 (clinicaltrials.gov: NCT04224987 ).

}, keywords = {Anti-Bacterial Agents, Azithromycin, Child, Child, Preschool, Drug Resistance, Bacterial, Humans, Infant, Macrolides, Mass Drug Administration, Niger, Randomized Controlled Trials as Topic}, issn = {1471-2458}, doi = {10.1186/s12889-021-10824-7}, author = {O{\textquoteright}Brien, Kieran S and Arzika, Ahmed M and Amza, Abdou and Maliki, Ramatou and Ousmane, Sani and Kadri, Boubacar and Nassirou, Beido and Mankara, Alio Karamba and Harouna, Abdoul Naser and Colby, Emily and Lebas, Elodie and Liu, Zijun and Le, Victoria and Nguyen, William and Keenan, Jeremy D and Oldenburg, Catherine E and Porco, Travis C and Doan, Thuy and Arnold, Benjamin F and Lietman, Thomas M} } @article {71, title = {Macrolide and Nonmacrolide Resistance with Mass Azithromycin Distribution.}, journal = {N Engl J Med}, volume = {383}, year = {2020}, month = {2020 11 12}, pages = {1941-1950}, abstract = {

BACKGROUND: Mass distribution of azithromycin to preschool children twice yearly for 2 years has been shown to reduce childhood mortality in sub-Saharan Africa but at the cost of amplifying macrolide resistance. The effects on the gut resistome, a reservoir of antimicrobial resistance genes in the body, of twice-yearly administration of azithromycin for a longer period are unclear.

METHODS: We investigated the gut resistome of children after they received twice-yearly distributions of azithromycin for 4 years. In the Niger site of the MORDOR trial, we enrolled 30 villages in a concurrent trial in which they were randomly assigned to receive mass distribution of either azithromycin or placebo, offered to all children 1 to 59 months of age every 6 months for 4 years. Rectal swabs were collected at baseline, 36 months, and 48 months for analysis of the participants{\textquoteright} gut resistome. The primary outcome was the ratio of macrolide-resistance determinants in the azithromycin group to those in the placebo group at 48 months.

RESULTS: Over the entire 48-month period, the mean ({\textpm}SD) coverage was 86.6{\textpm}12\% in the villages that received placebo and 83.2{\textpm}16.4\% in the villages that received azithromycin. A total of 3232 samples were collected during the entire trial period; of the samples obtained at the 48-month monitoring visit, 546 samples from 15 villages that received placebo and 504 from 14 villages that received azithromycin were analyzed. Determinants of macrolide resistance were higher in the azithromycin group than in the placebo group: 7.4 times as high (95\% confidence interval [CI], 4.0 to 16.7) at 36 months and 7.5 times as high (95\% CI, 3.8 to 23.1) at 48 months. Continued mass azithromycin distributions also selected for determinants of nonmacrolide resistance, including resistance to beta-lactam antibiotics, an antibiotic class prescribed frequently in this region of Africa.

CONCLUSIONS: Among villages assigned to receive mass distributions of azithromycin or placebo twice yearly for 4 years, antibiotic resistance was more common in the villages that received azithromycin than in those that received placebo. This trial showed that mass azithromycin distributions may propagate antibiotic resistance. (Funded by the Bill and Melinda Gates Foundation and others; ClinicalTrials.gov number, NCT02047981.).

}, keywords = {Anti-Bacterial Agents, Azithromycin, Child Mortality, Child, Preschool, Drug Resistance, Bacterial, Female, Gastrointestinal Microbiome, Humans, Infant, Macrolides, Male, Mass Drug Administration, Metagenome, Niger, Sequence Analysis, DNA}, issn = {1533-4406}, doi = {10.1056/NEJMoa2002606}, author = {Doan, Thuy and Worden, Lee and Hinterwirth, Armin and Arzika, Ahmed M and Maliki, Ramatou and Abdou, Amza and Zhong, Lina and Chen, Cindi and Cook, Catherine and Lebas, Elodie and O{\textquoteright}Brien, Kieran S and Oldenburg, Catherine E and Chow, Eric D and Porco, Travis C and Lipsitch, Marc and Keenan, Jeremy D and Lietman, Thomas M} } @article {121, title = {Longer-Term Assessment of Azithromycin for Reducing Childhood Mortality in Africa.}, journal = {N Engl J Med}, volume = {380}, year = {2019}, month = {2019 Jun 06}, pages = {2207-2214}, abstract = {

BACKGROUND: The MORDOR I trial (Macrolides Oraux pour R{\'e}duire les D{\'e}c{\`e}s avec un Oeil sur la R{\'e}sistance) 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{\textquoteright} original assignments.

RESULTS: In the MORDOR II trial, the mean ({\textpm}SD) azithromycin coverage was 91.3{\textpm}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{\textpm}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.).

}, keywords = {Anti-Bacterial Agents, Azithromycin, Child Mortality, Child, Preschool, Drug Administration Schedule, Female, Humans, Infant, Infant Mortality, Male, Mass Drug Administration, Niger}, issn = {1533-4406}, doi = {10.1056/NEJMoa1817213}, author = {Keenan, Jeremy D and Arzika, Ahmed M and Maliki, Ramatou and Boubacar, Nameywa and Elh Adamou, Sanoussi and Moussa Ali, Maria and Cook, Catherine and Lebas, Elodie and Lin, Ying and Ray, Kathryn J and O{\textquoteright}Brien, Kieran S and Doan, Thuy and Oldenburg, Catherine E and Callahan, E Kelly and Emerson, Paul M and Porco, Travis C and Lietman, Thomas M} }