Integrated Vector Management - Biological and Environmental Control of Disease Vectors - page 178

control. The inclusion of mass drug ad-
ministration (MDA) programmes, integrated
with ITN distribution, is an ef ective means of
reducing LF prevalence (Prybylski et al ., 1994;
Blackburn, 2006). The emphasis of the
programme was on community participation,
rather than using costly skilled workers, and,
perhaps in consequence, the uptake and
retention rates for the ITNs were high. As a
result, a year later, many of the most at risk
people were protected from exposure to both LF
and malaria. This study provides support for
future integrated campaigns on LF and malaria.
The annual MDA programme af ords the
opportunity for the coverage of ITNs and the
ei cacy of the nets against malaria and LF to be
monitored (van den Berg et al ., 2012). Using
vector control methods and MDA programmes
in conjunction will potentially reduce the
amount of time it takes to eliminate LF (Sunish
et al ., 2007).

Anopheles larvae (Ikemoto et al ., 1986; Andrade,
1992; Fillinger et al ., 2003; Majambere et al .,
2007; Kahindi et al ., 2008). It has been
suggested that microbial larvicides could be
incorporated within IVM programmes to
augment control ef orts aimed against adult
mosquitoes and/or larvae (Fillinger et al ., 2003;
Majambere et al ., 2007). Factors favouring the
use of Bti include its low toxicity to fi sh, but high
toxicity to Anopheles larvae, making it very
suitable to be used in combination with
predatory fi sh (Ikemoto et al ., 1986), and that
Bti produces a synergistic ef ect with the
synthetic organic larvicide Temephos (Andrade,
1992). Microbial larvicides have been used as a
single intervention against malaria in Tanzania
(Geissbuehler et al ., 2009) and The Gambia
(Majambere et al ., 2010) or in combination with
other interventions in IVM programmes, such as
the fi lling in of breeding sites in Eritrea (Shililu et
al ., 2007) and with ITNs in Tanzania (Fillinger et
al ., 2008) and Kenya (Fillinger et al ., 2009). All
of the aforementioned interventions resulted in
a reduction in malaria outcomes in the
treatment groups, and one study reported that
the use of microbial insecticides enhanced the
level of protection that was achieved with ITNs
alone (Fillinger et al ., 2009).
In addition to the use of larvicides,
environmental management of breeding sites, as
described previously (see Kondrasen et al .,
Chapter 9, this volume), is an important
component of LSM. Field studies that have
demonstrated a reduction in malaria trans-
mission, as a result of dif erent environmental
management interventions, include: fl ushing of
streams in the Philippines (Santiago, 1960);
larval habitat removal through the construction
of dams in India (Sharma et al ., 2008); and drain
maintenance in Tanzania (Castro et al ., 2009).
One important factor for the inclusion of LSM in
IVM programmes is the fact that malaria
transmission persists in many regions, despite
the implementation of ITNs and/or IRS directed
against endophilic mosquitoes, and LSM should
reduce mosquitoes that bite outdoors in addition
to house-entering mosquitoes (Fillinger and
Lindsay, 2011).
Nevertheless, support for the acceptance of
LSM in Global Malaria Control Programmes has
met some challenges:

10.3.1 Non-chemical tools for LF and
malaria IVM programmes

With the emergence of insecticide resistance to
synthetic pyrethroids, additional tools are
required for IVM programmes. The World Health
Organization Pesticide Evaluation Scheme
(WHOPES) is concerned with the development
of new tools and methods for malaria vector
control. In addition, WHOPES supports member
states and other stakeholders in their selection
of safe and judicious use of public health
pesticides. Non-chemical measures used for
larval control include biological control agents,
such as microbial or phytochemical larvicides
and predators (arthropods and fi sh), and larval
source management (LSM). Many of these
methods have been discussed comprehensively
in previous chapters of this volume, but the
potential role of microbial larvicides and LSM
requires further attention.
Two microbial larvicides, commonly used
in vector control, for example, against Simulium
damnosum larvae in the Onchocerciasis Control
Programme in West Africa (Akpoboua et al .,
1989), are the bacilli Bacillus thuringiensis
israelensis (Bti) and B . sphaericus (Bs). Several
studies have demonstrated their ability to kill