Malaria is a life-threatening disease that is transmitted through the bite of an infected female Anopheles mosquito. The life cycle of the mosquito has four stages: egg, larva, pupa and adult. The first 3 stages are aquatic (water bodies) and the adult stage is terrestrial. Larval source Management (LSM) is the management of aquatic habitats that are potential larval habitats for mosquitoes, LSM aims to prevent the completion of development of the immature stages (egg, larva and pupa). Thus, Larval source management refers to the targeted management of mosquito breeding sites, with the objective of reducing the number of mosquito larvae and pupae.
There are four main types of LSM:
- Habitat modification: a permanent alteration to the environment, e.g. land reclamation;
- Habitat manipulation: A recurrent activity, e.g. flushing of streams;
- Biological control: the introduction of natural predators into water bodies
- Larviciding: the regular application of biological or chemical insecticides to water
Larviciding is the regular application of biological or chemical insecticides to water bodies. Larviciding is recommended as a complementary intervention to augment the core interventions such as indoor residual spraying (IRS) and long-lasting insecticide nets (LLINs).
AngloGold Ashanti (Ghana) Malaria Control Limited (AGAMal) has been implementing IRS project intermittently in Obuasi complementing the primary intervention Indoor Residual Spraying.
The core intervention implemented against the malaria vector has been largely effective in reducing the burden of the disease in all operational districts.
AGAMal’s complementary larviciding project is carried out with Bacillus thurengiensis israelensis (Bti) in Obuasi Municipal area and Obuasi East District. Potential breeding sites are geotagged and characterized using the SnooCODE® mobile application and mapped using Google Earth®. This contributed to a more precise quantification of personnel, larvicide and increased efficiency in tracing the sites for treatment and re-treatment. Entomological monitoring was done to assess the juvenile and adult vector densities over the period.
Key characteristics of AGAMal’s LSM that have contributed to the successful project include but not limited to:
- Good project management
- Entomology unit staff having detailed knowledge of local vectors
- More importantly community acceptance and community support. Local employment procedures are followed in larvicide applicators.