We now hear from Sumitomo’s own John Lucas about the key strategies and technical advancements in the fight against malaria and insecticide resistance using mixed insecticide bed nets such as Olyset® Plus.
Transcript From Interview With John Lucas
Sumitomo Chemical is very proud to be involved in the fight against malaria primarily through the use of its Olyset® Net which is the first WHO recommended bed net on the market.
We set about 10 years ago starting to scale up production of that net and others followed and Sumitomo was very involved in this push for universal coverage which really helped meet many of the Millennium Development Goals.
All nets are coated with pyrethroid insecticides, they’re fantastically safe insecticides and very very effective against Malaria mosquitoes. One of the issues with that is that you don’t have this opportunity to rotate different classes of insecticides which is very very important in resistance management and that has given rise over the years to a slow but gradual increase in resistance in those mosquitos which is now reaching a point where we are starting to worry that nets are not delivering the performance that they should be and we may start to lose some of the gains that we’ve made over the last 10 years.
To try and address the issues of resistance we have developed a net called Olyset® Plus which contains piperonyl butoxide (PBO) and we see Olyset® Plus as an interim solution, it’s very very effective but it’s still treated with a pyrethroid but it’s got piperonyl butoxide there that synergises the action of the permethrin insecticide in the net and has really been shown to make a big difference in controlling resistant mosquitos in lab and field studies.
One of the problems of developing a net like this however is that of course with all the research and development that goes into it the net is going to cost more and we really have to move away from the notion that a net has a set cost and a set price so in the case of Olyset® Plus we are very confident that net, in areas where you have high levels of resistance, will deliver a better efficacy and most likely deliver a great reduction in mortality and morbidity due to malaria but currently nets aren’t being valued on any of those parameters purely on cost and that’s got to change.
Piperonyl butoxide is a great tool for combatting certain pyrethroid resistant strains but it is we see an interim tool in terms of rotational strategy, it’s much better to have different modes of action insecticides, different classes of insecticides and Sumitomo as an R&D based company are at the forefront of that activity in developing new chemistries and new products and new intervention.
We’re working now with IVCC the Innovative Vector Control Consortium to develop a net called Olyset® Duo and that net has just gone into the World Health Organisation for its approval and recommendation process and that product contains pyriproxyfen which is an insect growth regulator and has been shown in many many field and lab studies to be effective against resistant strains of mosquitos. Further down the track, and we’re talking hopefully by 2020, we’re again working with IVCC to develop new chemistries, new modes of action chemistries and we’re working on a project with them to identify a new chemical class that will be effective for use against resistant mosquitos.
Sumitomo is really playing its part in developing these new chemistries and working with stakeholders but I think it’s very very important for people on the ground to be vigilant National Malaria Control Programme (NMCP) managers, Ministry of Health (MOH) to keep their eyes open for any symptoms of resistance whether it’s failure of mosquitos to die when they are in contact with the net or resistance through the WHO tube test.
Where resistance levels are seen to start to rise it’s incumbent on those people to put pressure locally to say “What other solutions have we?” and I’m not just talking about switching from a standard bednet to an Olyset® Plus bednet, now that would be good, but also to look at other options, look at larvicides, look at space sprays maybe, but particularly indoor residual sprays, different solutions. Where people see resistance they need to be vigilant, they need to put pressure locally and on stakeholders but particularly if you have any more questions, if you have any more interest in this area, visit our website.