The public health strategy of mass drug administration (MDA) – the administration of antimicrobials to entire populations – poses an interesting conundrum. On the one hand, population-level administration of antimalarials or antibiotics can efficiently reduce morbidity and even mortality from infectious diseases. On the other hand, indiscriminate, untargeted use of antimicrobials drive antimicrobial resistance (AMR), and isn’t this exactly what we’re trying to stop with public health messaging and antimicrobial stewardship programs?

This puzzle will be examined in a symposium to be held at LSHTM on Weds 20 Feb, 'MDA and AMR: Cases of azithromycin, malaria and NTDs'. An interdisciplinary, international group of researchers and discussants will present original research, big-picture syntheses, and current thinking on this timely topic. Audience questions and participation are welcome. Sign up to attend in person, or you can join us by live-stream, if you can't be in London on the day. 

Here are a few optional pre-reads, for anyone who’d like to brush up on the topic before the event: MDA with chloroquine, including with medicated cooking salt, is now generally acknowledged to have contributed at least in part toward P. falciparum antimalarial resistance from the 1960s onward. Interest in MDA for malaria waned for several years, but more recently has returned as a tool in elimination and eradication campaigns; a 2013 Cochrane review and a 2016 Lancet ID viewpoint from Nick White provide helpful overviews of the balance between benefit and risk with MDA for malaria, and recent reports track resistance in areas where seasonal malaria chemoprophylaxis (SMC) has been used. Bridging between MDA with antimalarials and antibiotics is last month’s NEJM publication from Daniel Chandramohan and colleagues, reporting on the effect of adding azithromycin to SMC for children in West Africa; this study’s data on AMR are expected soon in a separate report. This report follows, and somewhat contradicts the results of, last year’s publication of primary results from the MORDOR study which found mortality benefit for azithromycin MDA among children in some sub-Saharan African regions. Since the 1990s, azithromycin has also been used in MDA campaigns for neglected tropical diseases (NTDs) such as trachoma and yaws, see also here for discussion of resistance in yaws; and alongside ivermectin for control of scabies and impetigo; and MDA with albendazole is used against soil-transmitted helminths.

Given the diversity of the biology of the affected micro-organisms, and of the antimicrobials’ mechanisms of action, the implications of MDA for AMR are likely to be nuanced and evolving. Come along on 20 Feb and join us for discussions!