Efficacy of mosquito coils containing 0.3% and 0.4% pyrethrins against An.gambiae sensu lato mosquitoes.

OBJECTIVE

To investigate the efficacy of a formulation containing 0.4% pyrethrins against registered mosquito coil containing 0.3% pyrethrins.

DESIGN

Non intervention analytical study.

SETTING

Four villages in Mashonaland East province, Mumurwi, Chitengu, Katiyo and Nyagande.

SUBJECTS

Biological efficacy of Doom and IT mosquito coils.

MAIN OUTCOME MEASURES

To measure insecticidal, knock down and inhibition of biting activities of the coils in the presence of mosquitoes.

RESULTS

A two hour exposure of mosquitoes to both coils results in a 99% and 98.5% mortality rate for a 0.4% and a 0.3% formulation respectively. The KT50 and KT90 of a formulation containing 0.4% pyrethrins were half those of a 0.3% formulation, suggesting that a 0.4% formulation has a rapid knock down effect. A formulation containing 0.4% pyrethrins inhibited 92.5% from biting as compared to a 0.3% formulation (80%).

CONCLUSION

A formulation containing 0.4% pyrethrins is more effective in repelling mosquitoes than a 0.3% formulation.