Introduction - Biological and Environmental Control of Disease Vectors - page 1

1 Introduction

Lena M. Lorenz* and Mary M. Cameron
London School of Hygiene & Tropical Medicine, London, UK

For the majority of people, the most obvious
example of using vector control for an infectious
disease that immediately springs to mind is that
of malaria control. Progress in the fi ght against
malaria has been headline news since Bill Gates
called for its eradication at the Gates Malaria
Forum in 2007 (Roberts and Enserink, 2007;
Tanner and de Savigny, 2008), which initiated
increased public and private spending for the
cause (RBM, 2011). Therefore, it is fi tting to
provide a synopsis of the classical example of
the history of malaria vector control, and its
limitations, prior to presenting an overview of
alternative methods based around environ-
mental and biological control. Throughout this
topic, both malaria control and the control of a
diverse array of other tropical vector-borne
diseases (Table 1.1) will be described in more
detail. A range of control methods other than
insecticides have been developed and employed
against disease vectors to combat site- and
species-specifi c ecological traits of vectors,
changes in disease patterns due to environ-
mental change and urbanization and the
evolution of resistance against chemical control
methods.

1.1 Malaria Control and its
Limitations

Malaria parasites are transmitted between
humans by species of the anopheline mosquito
complex. The very specifi c biting and blood
feeding behaviour of the main vector in sub-
Saharan Africa Anopheles gambiae sensu stricto,
namely indoor biting and resting during
evenings and at night time, has allowed the use
of targeted control tools, particularly indoor
residual spraying (IRS) with insecticides and
the use of insecticide-treated bed nets (ITNs)
(Pates and Curtis, 2005). However, alternative
methods of anopheline control now need to be
sought following a surge in insecticide resistance
in mosquitoes (Ranson et al ., 2011), potentially
rendering ITNs and IRS less ef ective in areas
with high levels of resistant mosquitoes (e.g. in
Benin; N'Guessan et al ., 2007; Asidi et al ., 2012).
In addition, the successful application of tools
targeting indoor mosquito activities has led to a
change in species composition from the specialist
An . gambiae s.s. to the more generalist An .
arabiensis females, which bite in- and outdoors
(Reddy et al ., 2011; Kitau et al ., 2012).

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