The importance of modelling the spread of insecticide resistance in a heterogeneous environment: the example of adding synergists to bed nets

Table 2 Parameters, symbols and subscripts used in the construction of the model

Parameter	Symbol
Dominance coefficient in each niche	h
Fitness cost of carrying a resistance allele	z
Selection coefficient in each niche	s
Baseline fitness level of susceptible homozygote in niches were insecticide is deployed	φ
Proportion of mosquitoes encountering a particular niche	α
Proportion of mosquitoes encountering ITN that also encounter the synergist	β
Impact of synergist	k
k=0; synergist completely effective: all mosquitoes encountering insecticide plus synergist die
k=1; synergist completely ineffective: mosquitoes encountering insecticide plus synergist die
at the same rate as those encountering insecticide alone (the model tracks survival in different niches -Table1, so the impact is on a reverse scale)
Subscripts
Male	m
Female	f
Insecticide free	n
Deployment of insecticide outside the house	o
Deployment of insecticide inside the house	i

ISSN: 1475-2875