What are the recognized global public‑health uses of ivermectin in mass‑drug‑administration campaigns and their impacts?
Executive summary
Ivermectin has been deployed for decades in coordinated mass‑drug‑administration (MDA) campaigns primarily to control and, in some settings, eliminate onchocerciasis (river blindness) and lymphatic filariasis, and it also plays established roles against scabies, strongyloidiasis and other soil‑transmitted helminths in public‑health programmes [1] [2] [3]. Recent research and policy roadmaps have explored expanding iMDA (ivermectin MDA) to exploit the drug’s mosquitocidal activity as a complementary malaria vector control tool, though population‑level malaria impact remains under active investigation and not yet proven at scale [4] [5] [2].
1. Proven uses in neglected tropical disease control and their outcomes
Ivermectin’s best‑documented public‑health role is in MDA against onchocerciasis and lymphatic filariasis, where repeated community distributions have reduced disease burden, prevented blindness and underpinned WHO elimination ambitions in many endemic regions; Merck’s donation programmes and long‑running WHO partnerships catalysed those successes [1] [6] [7]. The drug is WHO‑listed as essential for antifilarial and antiectoparasitic treatment and has been central to global programmes that now give ivermectin to hundreds of millions of people annually or semi‑annually as part of coordinated campaigns [1] [7].
2. Expanded NTD and community‑health benefits beyond filariasis
Beyond filarial disease, ivermectin is widely used in MDA for scabies and strongyloidiasis and, in combination with other anthelmintics, against some soil‑transmitted helminths such as trichuriasis; these programs can yield broad community health improvements in heavily polyparasitized, resource‑poor settings [3] [8] [9]. Field delivery innovations — including height‑based dose poles and discussions of fixed‑dose formulations — reflect operational learning from decades of MDA and aim to increase coverage and simplify deployment in low‑resource campaigns [4] [3].
3. The promise and limits of ivermectin as a vector control tool for malaria
Laboratory and clinical evidence show ivermectin shortens the lifespan of Anopheles mosquitoes that feed on treated humans or livestock, creating a plausible mechanism to cut malaria transmission when delivered at community scale [4] [2]. Global roadmaps and modelling studies have proposed iMDA as a complementary vector control method to address residual transmission and insecticide resistance, but simulations and systematic reviews emphasize that health impact, optimal dosing regimens, safety at higher or repeat doses, cost‑effectiveness and environmental and resistance risks require further large trials and policy translation [4] [5] [2].
4. Safety, programmatic risks and reputational spillovers from COVID‑19 controversies
Ivermectin has an established safety profile in the context of NTD MDA, but adverse events sometimes reflect disease‑drug interactions rather than drug toxicity; nonetheless, misuse and politicized promotion of ivermectin for COVID‑19 led several governments to procure and distribute it outside evidence‑based frameworks, creating documented diversion of supplies and erosion of community trust that may jeopardize NTD campaigns [6] [10] [7] [11]. Major health authorities — including WHO, FDA and EMA — advised against routine use of ivermectin for COVID‑19 outside trials, and analyses of the pandemic period show both misinformation‑driven demand surges and government kit distributions with weak clinical justification [12] [10] [11].
5. Trade‑offs, research gaps and the path forward for MDA policy
Programmatic success to date demonstrates that ivermectin MDA can be a cost‑effective public‑health strategy against specific NTDs when delivered within sustained, community‑trusted platforms supported by drug donation and surveillance systems [6] [1]. However, expanding indications — especially for malaria control — requires resolving unanswered questions on optimal dosing regimens, resistance monitoring, environmental impact, ethical consent in community‑level prophylaxis, and rigorous evidence of population‑level effectiveness from large clinical trials and operational research [4] [5]. The literature and WHO roadmaps advocate careful, evidence‑driven translation of ivermectin’s promising biology into policy while protecting core NTD programmes from supply shocks and misinformation [4] [7].