Innovations in Malaria Vector Control Towards Elimination

1. Innovations in Malaria Vector Control Towards Elimination BWAMBOK B K 1st Rwanda Malaria Forum Kigali, 27th September 2012

2. Gains in Malaria Control are Immense and Real • National and international efforts to tackle malaria are working. • With the rapid scale up of life-saving interventions we have seen a consistent reduction in global malaria cases and deaths over the last five years. • Within the last decade, malaria death rates in Africa alone have dropped by one-third, while 35 of the 53 countries affected by malaria outside of Africa have successfully cut cases by more than 50%. http://www.who.int/malaria/world_malaria_report_2011/en/ • Just by scaling up efforts to prevent malaria, including universal coverage of mosquito nets, we will save the lives of an estimated three million African children by 2015. http://www.rbm.who.int/ProgressImpactSeries/report3.html

3. Challenges in tools towards elimination Will be motivated by Low Parasite Prevalence / Low vector density in a resource constrained environment • Diagnosis- Test sensitivity and specificity • Treatment- Drug resistance • Vector control- Insecticide resistance • Community/ household- Utilization

4. Effective vector control is essential for pre-elimination • Vector control is indispensable for reducing transmission • Only approach capable of bringing intense or moderate transmission down to low levels where elimination is within reach • Plays critical role in knocking out last foci of transmission in later stages of elimination • It is essential that insecticidal tools (IRS, LLINs) remain highly effective so as to reduce vector population size and longevity Allocation of malaria suppression measures to different phases of an elimination program SOURCE: MALARIA ELIMINATION GROUP (2009)

5. Effective vector control is essential for pre-elimination • As vector densities and/or longevity decrease it is important that selective pressure is minimized • Cessation of anti-vector activities or even loss of efficacy can lead to parasite reinvasion in a non-immune human population There will always be some survivors in a population following insecticide exposure and it is more likely that these are resistant individuals The survivors reproduce and the proportion of resistant individuals increases If there is further exposure to the same insecticide, resistance may become common SOURCE: INSECTICIDE RESISTANCE ACTION COMMITTEE (2011)

6. Rationale use of insecticides is critical • Insecticide resistance and the limits of our current vector control tools threaten our global progress against vector-borne diseases • Insecticide Resistance Management strategies should: • Be implemented in broader context of integrated vector management • Delay the loss of insecticide susceptibility • Prolong the effective life of currently available interventions FINE-SCALE MOSAIC MIXTURE ROTATION SOURCE: INSECTICIDE RESISTANCE ACTION COMMITTEE (2011)

7. Efficacy of current tools must be preserved Hypothetical vector control programme cost with resistance management and without resistance management Failure to successfully manage resistance has well documented financial implications and failure to implement an IRM programme on financial grounds is a false economy that will lead to increased costs in the future = WE MUST PRESERVE THE EFFICACY OF CURRENT TOOLS WHILST AWAITING NEW TOOLS SOURCE: INSECTICIDE RESISTANCE ACTION COMMITTEE (2011)

8. Efficacy of current tools must be preserved SOURCE: WHO GLOBAL PLAN FOR INSECTICIDE RESISTANCE MANAGEMENT IN MALARIA VECTORS (2012) = WE MUST PRESERVE THE EFFICACY OF CURRENT TOOLS WHILST AWAITING NEW TOOLS

9. There are limited options for vector control • Resistance has now been reported to all classes of insecticides recommended for adult vector control • Only two modes of action are currently available for adult vector control: • Acetylcholinesterase inhibitors (Carbamates, Organophosphates) • Sodium channel modulators (Pyrethrins, Pyrethroids, DDT) • Mixtures are complicated as degradation profiles need to be similar for all active ingredients • Rotations and fine-scale mosaics are not appropriate for LLINs • Options for LLINs are: • Use of non-pyrethroid only • Combining pyrethroids with synergists • Combining non-pyrethroids with pyrethroids • Options for IRS -LLIRS paradigm-Wall Spray/ Wall Linning -Mixtures

10. Innovative tools are urgently required New tools are urgently required for deployment though there are technical, financial and programmatic barriers that hinder the pace of development and introduction of innovative tools Fostering the introduction of innovative vector control tools for public health, Report from a Stakeholder Workshop held in Paris on 1-2 March, 2012

11. New formulations are in pipeline or ready for deployment • Combination LLIN • DuPont • OlysetDuo® Sumitomo • PermaNet® 3.0 • Vestergaard Frandsen • Chlorphenapyr/alpha-cypermethrin, BASF • OlysetPlus® • Sumitomo • Chlorphenapyr • BASF • Pyrimephos-methyl • Syngenta • LLIRS • DuPont • Deltamethrin LLIRS • Bayer

12. Pathway for introduction of new tools is unclear Impetus is on countries to generate own data based on local vector species behavior, susceptibility status etc. and user acceptability in order to inform evidence-based vector control decisions ? What are the right guidelines for testing a particular novel product? ? How much and what type of data are required to conclude that the novel product is appropriate for adoption? (adaption…..) ? What are the mechanisms for review and validation of local data towards policy adoption? ? How much data is required by donors to be convinced of the need for a change to a novel product, especially if there are cost implications? • Action must be immediate and pre-emptive, not responsive. But how much and what proof is needed for introduction of novel products? And how can this process be sped up?

13. Evidence-based vector control is essential • While awaiting new insecticidal actives / modes of action, we must be extremely careful with our current tools • It is essential that monitoring is conducted to ascertain baseline susceptibility and that changes are monitored over time • Focus should be on generating local data for informing control strategies • Preference should be given to tools with the highest efficacy that provide protection for the full intended lifetime (ie. minimum 3 years for LLINs) • This is especially critical in pre-elimination/elimination as insecticide resistance can seriously threaten significant gains made Most experts consider that insecticide resistance will likely have significant operational impact if no preemptive action is taken.

14. ASANTE SANA