Guidelines

1
Vector control issues and new technologies Dr
Pierre Guillet Global Malaria Programme Vector
Control and Prevention 6th Intercountry meeting
of National Malaria Programme Managers Cairo, 3
6 July 2006
2
Vector control and prevention objectives

• Vector control to be expanded using ITNs and IRS
• Long-Lasting Insecticidal Nets to be used
• Obviate the need for re-treatment campaigns
• Cheaper than conventionally treated nets
• Targeting full coverage as an immediate objective
  to protect all populations at risk of malaria
• 1 LLIN for 2 persons at risk of malaria
• Simpler to achieve
• Plans for replacement of LLINs once exhausted

3
What is a LLIN?

• WHO definition
• 20 standard washes
• 3 years
• 2 recommended products
• Olyset PermaNet 2.0
• Life-time of a LLIN
• Polyester 3 years
• Polyethylene 5 years

4
Olyset efficacy

• Several trials concluded to good efficacy for 5
  up to 7 years.
• On going Tanzania multi-village trial almost
  complete interruption of transmission with both
  Olyset PermaNet for more than 18 consecutive
  months
• Efficacy against leishmaniasis vectors confirmed
• CDC results rapid loss of efficacy based on WHO
  test cone and slow regeneration after washing.
• Need for standardized test methods and procedures
• Difficulty in testing efficacy of permethrin
  treated materials

5
WHO test cones (3 minutes exposure, forced
contact)
6
Tunnel test (12 hours, free flying mosquitoes)
7
WHO test tubes (3 minutes, forced exposure)
8
Test method efficacy of treated nettings
Permethrin 500 mg/m2
Deltamethrin 25 mg/m2
9
New LLINs under WHOPES evaluation

• 8 new LLINs under WHOPES testing
• Expected dates for WHO recommendation
• Dec 06 1 (BASF Germany)
• June 07 4 (Tana Netto, Thailand Yorkool
  Genfont, China)
• Dec 07 3 (Clark USA, Syngenta Switzerland, IIC
  France)
• Current production capacity 5.3 million/month
  with 2 producers (63.6 millions/year).
  Need for planning orders.
• Average FOB price 4.5 to 5.5 US /net X-family
  size (1.6 W x 1.8 L x 1.5 H)

10
Expected production capacity(based on products
already in WHOPES)
11
Costs for LLINs procurement distribution
(4)
(1 1.5)
IFRC Joint LLIN/EPI campaigns, Hoyer 2006, LSHTM

• Interesting developments in Africa linking ITN
  distribution with EPI activities (routine and
  campaigns) ANC services
• Opportunity for achieving full LLIN coverage

12
All mosquito nets to be treated

• Treatment of conventional nets (new or in use)
• Development of long-lasting treatment kits (LLT
  kit)
• 2 LLT kits under WHOPES evaluation (expected Dec
  06 Bayer Dec 07 Syngenta)
• Achieving full insecticide coverage
• Public sector to purchase LLINs only
• National program to treat existing conventional
  nets with LLT kits
• Nets locally made or sold through retail market
  to be bundled with LLT kits

13
African Network for Vector Resistance
(ANVR)Permethrin resistance in An. gambiae s.s.
Kdr mutation East
Kdr mutation West
Kdr frequency in Uganda
Kdr frequency in CAR
Data 2000 - 2005
Susceptible
West
Resistance to be confirmed
East
Resistant
Highly resistant
14
Selection of resistance, a fast evolving process

• West Africa
• Rapid progression of kdr mutation Northward in
  An. gambiae M form (central Côte d'Ivoire from
  less 1 AF in 1995 to more than 40 in 2003).
  Now present in Burkina Faso
• Rapid increase in frequency of kdr in An.
  arabiensis currently observed throughout West and
  East Africa
• Introgression of resistance genes in sibling
  species
• Dispersal of vectors, population dynamics and
  gene flow, are major factors conditioning
  evolution of insecticide resistance

15
Need for improved resistance monitoring

• Resistance monitoring to be part of routine
  operational activities. Need for
• strengthening capacity of MNCP to implement
  monitoring
• national reference laboratory
• specific funding (GFATM, bilateral)
• regional network for resistance monitoring
  management
• Operational impact of resistance to be assessed
• Resistance management tactics (e.g. rotations) to
  be locally adapted, especially for residual
  spraying larval control programs

16
Threats to large scale ITN implementation

• Availability of LLINs
• Acceptability
• Mechanisms for rapid scale-up
• Pyrethroid resistance in case of kdr, no
  immediate threat to implementation but concerns
  in Benin

17
ITNs loss of efficacy in Southern
Benin(experimental huts, An. gambiae)
Data M. Rowland, LSHTM
18
How to address resistance with ITNs?

• Short term response
• using non-pyrethroids to restore efficacy against
  resistant vectors (Ops, carbamates?)
• tentative combination of insecticides on nets to
  manage resistance
• Medium term combine ITNs (as well as IRS) with
  other interventions in the context of integrated
  vector management
• Longer term solution development of a new
  insecticide alternative to pyrethroids

19
IRS loss of efficacy in Southern
Benin(experimental huts, An. gambiae)
Data M. Rowland, LSHTM
20
Insecticides for IRS no miracle expected

• DDT (residual efficacy 6 to 12 months)
• still the cheapest and easiest to use (price,
  residual efficacy)
• no longer used in agriculture (resistance)
• to be maintained as long as a suitable
  alternative is available
• Pyrethroids (3 to 6 months)
• six products but equivalent to 1 as far as
  resistance is concerned
• not an alternative to DDT in kdr areas
• Ops (2 to 3 months) Carbamates (3 to 6 months)
• share a common resistance mechanism (modified
  AChE)

21
New products for IRS?

• Longer-lasting formulations (IVCC Gates
  Foundation)
• microcapsuled Chlorpyrifos-methyl (Reldan)
• bendiocarb resin based formulation (?)
• Already existing contact insecticide
  chlorfenapyr (pyrrole)
• different mode of action (no cross resistance
  with pyrethroids)
• low mammalian toxicity
• on going testing in experimental huts (ITNs
  IRS)
• Development of new contact insecticides (NIH,
  NIAID, Gates Foundation (Grand Challenge, IVCC)

22
Restoring IRS efficacychlorpyrifos methyl
(experimental huts, An. gambiae)
Data M. Rowland, LSHTM
23
Larvicides a range of new products

• Temephos (Abate) to disappear (EU Biocide)
• B. thuringiensis H 14
• Vectobac WDG tablets for drinking water (dry
  formulations)
• Pyriproxifen (IGR)
• Sumilarve granules (5 to 10 grams/ha, gt 6 weeks
  efficacy)
• Slow release chips 20 ppb, gt 6 months efficacy
  in tanks/cisterns
• Spinosins (under WHOPES evaluation)
• Spinosad, 1ppm, 3 months efficacy in closed
  breeding sites (alternative to temephos?).
• Novaluron (IGR) (10 to 100 grams/ha),
  Dinetofuranand others

24
New approaches fumigant insecticide

• Metofluthrin (SumiOne, Sumitomo)
• evaporation at room temperature
• efficacy from 1 night to 8 weeksor more (up to 6
  months?)
• safe alternative to coils. Alternative to IRS or
  ITNs?
• need for field testing efficacy against
  pyrethroid resistant strains

SumiOne matrix 8 weeks testing in West Africa
(data IRD, Benin)
25
New products for specific applications

• Insecticide incorporated plastic sheeting (ITPS,
  80 gsm, HDPE) for refugee settings and
  emergencies
• 2 tarpaulins under development
• 1 commercial (ZeroFly deltamethrin, Vestergaard)
• 1 experimental (permethrin, Sumitomo)
• tents

26
New products for specific applications

• Insecticide incorporated plastic film (24 gsm
  HDPE, 2 permethrin) for indoor use
  (wall and/or roof lining)
• On going testing in Benin (experimental huts) and
  Iran (Baluchistan, village trial) for efficacy,
  feasibility and acceptability. Minimum 5 years
  efficacy targeted.

27
New products for specific applications

• Long lasting insecticide treated curtains
• Protection against domestic pests, malaria,
  dengue, Chikungunya
• Long-lasting treated blankets for refugee
  settings
• Wide range of possibilities opportunities
• Need for program managers to express their needs
  and expectations. WHO to stimulate industry to
  get the right technology for the right
  application.