Introduction - Biological and Environmental Control of Disease Vectors - page 2

Table 1.1. Summary of vectors of tropical infectious diseases and potential control methods.

Lost DALYs a
(millions) b

Number of
countries
with active
transmission a

(Potential) Vector control
methods Vector (genus) Disease Total %

Mosquitoes
( Anopheles ,
Culex , Stegomyia )

Malaria 99 45.0 74 ITNs, IRS, LSM,

synthetic and
botanical
semiochemicals,
fungi, fi sh, arthropods,
house screening,
water management

Lymphatic fi lariasis 72 5.8 10

Dengue >100 0.7 1

Japanese
encephalitis

40 0.4 1

Housefl y, fi lth fl y,
blow fl y ( Musca ,
Calliphora ,
Chrysomya )

Trachoma 57 2.3 4 Sanitation, water

management, house
screening, LSM
(onchocerciasis),
ITNs/IRS
(leishmaniasis)

Enteric/diarrhoeal
diseases

191 n/a n/a

Blackfl y ( Simulium ) Onchocerciasis 37 0.5 1

Sandfl y ( Lutzomyia ,
Phlebotomus )

Leishmaniasis 88 2.1 3

Tsetse fl y ( Glossina ) Human African

trypanosomiasis

37 n/a n/a Semiochemicals in

combination with
insecticides

Snails
( Biomphalaria ,
Bulinus )

Schistosomiasis 60 1.7-4.5 6 Water management

Kissing bugs
( Rhodnius ,
Triatoma )

Chagas disease 21 0.7 1 House screening, ITNs,

IRS

a From WHO (2012a).
b The disability-adjusted life year (DALY) is a measure of overall disease burden, expressed as the number of years lost
due to ill-health, disability or early death.
ITNs, insecticide-treated nets; IRS, indoor residual spraying; LSM, larval source management; n/a: not quantifi ed.

1.1.1 Malaria control during the pre- and
post-DDT era

sites, and improving human habitation and
sanitation to reduce the number of disease
vectors in a given area (Walker and Lynch,
2007). Often, these strategies aim to promote
community participation and enhance com-
munity benefi ts without polluting the environ-
ment. In Malaysia, specifi c environmental
control methods were employed after the local
mosquito vectors and their ecological breeding
requirements had been identifi ed. Indoor
residual spraying, ITNs and personal protection
measures were combined with house screening,
clearance of vegetation to remove shade
required by the anopheline larvae and environ-
mental modifi cation, including the installation
of automatic siphons to fl ush streams, drains
packed with coconut husk to create stable

Before the discovery of DDT (dichlorodiphenyltri-
chloroethane) in the 1940s, early disease
control programmes included environmental
and biological methods, such as house screening
and the drainage of swamps and other breeding
sites (Rozendaal, 1997; Keiser et al ., 2005). For
example, on the island of Java in Indonesia,
periodic drainage of rice fi elds and cleaning of
fi sh ponds helped to eliminate malaria; a success
that is still evident now 80 years after imple-
mentation (Raghavendra et al ., 2011). Generally,
environmental management strategies focus on
changing natural habitats by removing existing
or avoiding the creation of new vector breeding