The potential impact of moxidectin on onchocerciasis elimination in Africa: an economic evaluation based on the Phase II clinical trial data

Abstract

BackgroundSpurred by success in several foci, onchocerciasis control policy in Africa has shifted from morbidity control to elimination of infection. Clinical trials have demonstrated that moxidectin is substantially more efficacious than ivermectin in effecting sustained reductions in skin microfilarial load and, therefore, may accelerate progress towards elimination. We compare the potential cost-effectiveness of annual moxidectin with annual and biannual ivermectin treatment.MethodsData from the first clinical study of moxidectin were used to parameterise the onchocerciasis transmission model EPIONCHO to investigate, for different epidemiological and programmatic scenarios in African savannah settings, the number of years and in-country costs necessary to reach the operational thresholds for cessation of treatment, comparing annual and biannual ivermectin with annual moxidectin treatment.ResultsAnnual moxidectin and biannual ivermectin treatment would achieve similar reductions in programme duration relative to annual ivermectin treatment. Unlike biannual ivermectin treatment, annual moxidectin treatment would not incur a considerable increase in programmatic costs and, therefore, would generate sizeable in-country cost savings (assuming the drug is donated). Furthermore, the impact of moxidectin, unlike ivermectin, was not substantively influenced by the timing of treatment relative to seasonal patterns of transmission.ConclusionsMoxidectin is a promising new drug for the control and elimination of onchocerciasis. It has high programmatic value particularly when resource limitation prevents a biannual treatment strategy, or optimal timing of treatment relative to peak transmission season is not feasible.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-0779-4) contains supplementary material, which is available to authorized users.

Genome-wide analysis of ivermectin response by Onchocerca volvulus reveals that genetic drift and soft selective sweeps contribute to loss of drug sensitivity

“…With respect to SORs, genotyping assays will benefit control programmes in multiple ways by (i) providing diagnostic tools to monitor changes in the frequency of SORs (non-invasive through genotyping infective larvae in the vector [ 109 ]), (ii) discriminating between genetic explanations for persistence of transmission (i.e., presence/selection for SOR) and other factors that determine CDTI success (such as host-related factors, treatment coverage and compliance, pre-control prevalence and intensity of infection and vector biting rates [ 48 – 53 , 107 ]), (iii) suggesting a trigger for the initiation of alternative treatment strategies, such as anti- Wolbachia treatment [ 110 , 111 ], local vector control, new treatments that may become available such as moxidectin [ 46 , 112 ], combinations of interventions, or novel macrofilaricides (as reviewed in [ 113 ]) in populations where persistent transmission is observed despite prolonged CDTI [ 114 ].…”

Factors affecting onchocerciasis transmission: lessons for infection control

“…Other entomological issues related to ivermectin delivery concern the need to time interventions at the times when transmission is at its height. This is because modelling has shown that the timing of drug distributions in relation to seasonal transmission peaks has an impact on the period needed for a MDA programme to achieve maximum reductions in skin microfilarial loads [91]. The frequency of ivermectin treatments is also a factor.…”

Genome-wide analysis of ivermectin response byOnchocerca volvulusreveals that genetic drift and soft selective sweeps contribute to loss of drug sensitivity

“…With respect to SORs, genotyping assays will benefit control programs in multiple ways by (i) providing diagnostic tools to monitor changes in the frequency of SORs (e.g. genotyping infective larvae in the vector), (ii) discriminating between genetic explanations for persistence of transmission (i.e., selection for SOR) and other factors that determine CDTI success (such as host-related factors, treatment coverage and compliance, pre-control prevalence and intensity of infection and vector biting rates [48–53, 99]), and (iii) suggesting a trigger for the initiation of alternative treatment strategies, such as anti-Wolbachia treatment [101, 102], local vector control, or new treatments that may become available sooner or later like moxidectin [46, 103], or combination treatments, flubendazole or emodepside (as reviewed in [104]) in populations where persistent transmission is observed in spite of CDTI [105].…”