Adult vector control, mosquito ecology and malaria transmission.
BACKGROUND
Standard advice regarding vector control is to prefer interventions that reduce the lifespan of adult mosquitoes. The basis for this advice is a decades-old sensitivity analysis of 'vectorial capacity', a concept relevant for most malaria transmission models and based solely on adult mosquito population dynamics. Recent advances in micro-simulation models offer an opportunity to expand the theory of vectorial capacity to include both adult and juvenile mosquito stages in the model.


METHODS
In this study we revisit arguments about transmission and its sensitivity to mosquito bionomic parameters using an elasticity analysis of developed formulations of vectorial capacity.


RESULTS
We show that reducing adult survival has effects on both adult and juvenile population size, which are significant for transmission and not accounted for in traditional formulations of vectorial capacity. The elasticity of these effects is dependent on various mosquito population parameters, which we explore. Overall, control is most sensitive to methods that affect adult mosquito mortality rates, followed by blood feeding frequency, human blood feeding habit, and lastly, to adult mosquito population density.


CONCLUSIONS
These results emphasise more strongly than ever the sensitivity of transmission to adult mosquito mortality, but also suggest the high potential of combinations of interventions including larval source management. This must be done with caution, however, as policy requires a more careful consideration of costs, operational difficulties and policy goals in relation to baseline transmission.
Spatial Ecology and Epidemiology Group, Department of Zoology, Oxford University, Oxford, UK oliver.brady@zoo.ox.ac.uk.
Oliver J
OJ
Brady
Department of Zoology, University of Oxford, UK.
H Charles J
HC
Godfray
Department of Geography and Environment, University of Southampton, Southampton, UK Fogarty International Center, NIH, Bethesda, MD, USA Flowminder Foundation, Stockholm, Sweden.
Andrew J
AJ
Tatem
Spatial Ecology and Epidemiology Group, Department of Zoology, Oxford University, Oxford, UK.
Peter W
PW
Gething
Clinton Health Access Initiative, Boston, MA, USA.
Justin M
JM
Cohen
Fogarty International Center, NIH, Bethesda, MD, USA.
F Ellis
FE
McKenzie
Fogarty International Center, NIH, Bethesda, MD, USA Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA Department of Entomology and Nematology, University of California, Davis, CA, USA.
T
T
Alex Perkins
Fogarty International Center, NIH, Bethesda, MD, USA Department of Entomology and Nematology, University of California, Davis, CA, USA Department of Epidemiology and Biostatistics, Indiana University, Bloomington, IN, USA.
Robert C
RC
Reiner
Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK.
Lucy S
LS
Tusting
Fogarty International Center, NIH, Bethesda, MD, USA Department of Entomology and Nematology, University of California, Davis, CA, USA.
Thomas W
TW
Scott
School of Biological Sciences, Durham University, Durham, UK.
Steven W
SW
Lindsay
Spatial Ecology and Epidemiology Group, Department of Zoology, Oxford University, Oxford, UK Fogarty International Center, NIH, Bethesda, MD, USA.
Simon I
SI
Hay
Spatial Ecology and Epidemiology Group, Department of Zoology, Oxford University, Oxford, UK Fogarty International Center, NIH, Bethesda, MD, USA Sanaria Institute for Global Health and Tropical Medicine, Rockville, MD, USA.
David L
DL
Smith
D000328:Adult; D000818:Animals; D000852:Anopheles; D009033:Culicidae; D004463:Ecology; D006291:Health Policy; D006801:Humans; D007303:Insect Vectors; D007814:Larva; D008018:Life Cycle Stages; D008288:Malaria / Q000517:prevention & control* / Q000635:transmission; D008954:Models, Biological; D009032:Mosquito Control; D011156:Population Density; D011157:Population Dynamics
Larval control; Malaria control policy; Micro-simulation models; Plasmodium falciparum; Plasmodium vivax; Vectorial capacity