In recent years, the scale-up of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) has greatly reduced malaria transmission. However, malaria remains a global public health concern with the majority of the disease burden in sub-Saharan Africa. Insecticide resistance is a growing problem among Anopheles vector populations, with potential implications for the continued effectiveness of available control interventions. Improved understanding of current resistance levels and underlying mechanisms is essential to design appropriate management strategies and to mitigate future selection for resistance.
Incorporating quantitative measures of resistance strength, and utilizing bioassays with field doses of insecticides, will help interpret the possible impact of resistance on vector control activities.
In contrast to previous laboratory investigation, ICON(R) Maxx-treated nets showed only moderate KD and mortality rates.
This study showed that unwashed PermaNet(R) 3.0 caused significantly higher mortality against pyrethroid resistant An. gambiae s.s and Culex spp than PermaNet(R) 2.0 and the CTN.
An adaptive response to the presence of multiple insecticide classes necessarily involves the development of multiple resistance mechanisms whose effectiveness may be enhanced by intra-population variation in the expression of resistance phenotypes.
Malaria transmission exists in both town, but with high difference in the level of risk.
Since An. arabiensis shows high levels of resistance to DDT in all villages tested and varying pyrethroid resistance in Gorgora and the Ghibe River valley, precautionary measures should be taken in future vector control operations. Moreover, the status of resistance in other locations in Ethiopia and the spread of resistant gene (s) should be investigated.
In this study, we employ haplotype diversity analysis to examine evidence for selective sweeps around knockdown resistance (kdr) mutations associated with resistance to dichlorodiphenyltrichloroethane and pyrethroid insecticides in the mosquito Anopheles gambiae.
Standard WHO insecticide susceptibility tests were conducted on adults reared from larval and pupal collections from breeding sites at three villages namely: Sodere in the Rift Valley, Gorgora in the north and Ghibe River Valley in the south west of Ethiopia.
Our data show that strong, recent positive selective events, such as those caused by insecticide resistance, can be identified in wild insect populations.