Insecticide treated nets work by providing personal protection to the sleeper under the net, as well as to the entire community by elimination of vector-borne diseases disseminated by blood-feeding mosquitoes.
Critically, this protection can only work if the mosquito is not resistant to the insecticide on the net, and today we are seeing increases in both the frequency and strength of resistance to pyrethroids (the main class of insecticide used for treated nets) across Africa. To combat the threat of insecticide resistance, IVCC and BASF developed the Interceptor® G2. The Interceptor® G2 is a Long Lasting Insecticidal Net (LLIN) combining a pyrethroid (alphacypermethrin), with a pyrrole insecticide (chlorfenapyr), a first in 30 years.
Technical details
Interceptor® G2 is a second-generation LLIN developed by BASF with a combination of chlorfenapyr and alpha-cypermethrin to control insecticide resistant mosquitoes. This novel mode of action in vector control exploits mosquito enzymatic systems against themselves and shows no cross-resistance to other insecticide classes. Interceptor® G2 is a multifilament polyester net produced with a unique textile-finishing process developed by BASF’s textile technologists using a proprietary polymer system. It contains 200 mg/m2 chlorfenapyr and 100 mg/m2 alpha-cypermethrin.
On mosquito netting, chlorfenapyr is toxic to insecticide resistant and susceptible mosquitoes. It lacks the property of typical pyrethroid excito-repellency, crucial for reducing mosquito biting rates and providing personal protection to net users.
In Interceptor® G2 the pyrethroid component alpha-cypermethrin provides excito-repellency and personal protection, whilst the chlorfenapyr component restores insecticidal activity against insecticide resistant mosquitoes.
Benefits and features
When used as a coating on mosquito netting, chlorfenapyr kills both insecticide-resistant and insecticide-susceptible mosquitoes but does not repel the insects immediately. As excito-repellent activity is important for reducing mosquito biting rates and providing personal protection to sleepers, a pyrethroid component, alpha-cypermethrin, has been added to ensure repellency and personal protection, whilst chlorfenapyr ensures insecticidal activity against mosquitoes.
The active ingredient, chlorfenapyr, was first launched in 1995 and is currently registered and used in over 40 countries around the world for a variety of agricultural and non-crop uses. It is already known for its efficacy in agriculture and urban pest control where, in many countries, it is registered for food-handling areas or areas where food is served and stored.
The assessment of risk to humans of washing and sleeping under the Interceptor® G2 LLIN following the World Health Organization (WHO) Generic Risk Assessment Model for insecticide-treated nets on behalf of WHO concluded that when used as instructed, Interceptor® G2 LLIN is safe.
Performance
Unlike pyrethroids and all other classes of insecticide currently recommended for adult mosquito control, the chlorfenapyr target site of activity is not the insect nervous system.
Unlike pyrethroids and all other classes of insecticide currently recommended for adult mosquito control, the chlorfenapyr target site of activity is not the insect nervous system. Instead, chlorfenapyr acts, after being metabolized by P450 enzymes at the cellular level, by disrupting respiratory pathways and proton gradients through the uncoupling of oxidative phosphorylation within the mitochondria. Current WHO guidelines for identifying new insecticides and measuring toxic activity against malaria vectors are based on historic precedents established for neurotoxins, such as pyrethroids, organochlorines, carbamates, and organophosphates.
Interceptor® G2 kills about 70 – 97% of the total mosquitoes already after 24 hours, comparable to the pyrethroid-only LLIN Interceptor®.
Industry partner
- A Chlorfenapyr Mixture Net Interceptor® G2 Shows High Efficacy and Wash Durability against Resistant Mosquitoes in West Africa
- Efficacy of Interceptor® G2, a new Long Lasting Insecticidal Net (LLIN) against wild pyrethroid-resistant Anopheles gambiae s.s. from Côte d’Ivoire: a semi-field trial
- Which intervention is better for malaria vector control: insecticide mixture Long Lasting Insecticidal Nets (LLINs) or standard pyrethroid nets combined with Indoor Residual Spraying (IRS)?
- Evaluation of efficacy of Interceptor® G2, a Long Lasting Insecticidal Net (LLIN) coated with a mixture of chlorfenapyr and alpha-cypermethrin, against pyrethroid resistant Anopheles gambiae s.l. in Burkina Faso