Characterization of Anopheles gambiae s.l. and insecticide resistance profile relative to physicochemical properties of breeding habitats within Accra Metropolis, Ghana

Abstract

Malaria is endemic in Ghana as in most countries of sub-Saharan Africa. This study was conducted to characterize Anopheles gambiae s.l. and determine pyrethroid resistance profiles relative to physicochemical properties of breeding habitats in Accra, Ghana. Eight aquatic habitats containing Anopheles larvae were identified and from each habitat, larvae and water were sampled. Adult An. gambiae reared from larvae were morphologically identified and tested for permethrin (0.75%) and deltamethrin (0.05%) resistance using WHO bioassay method. An. gambiae s.s. found were identified to their molecular levels and kdr mutation detected using PCR-based methods. Twenty-nine physicochemical parameters of each water sample were measured and their levels connected with pyrethroid resistance and proportions of An. gambiae s.s. molecular forms in habitats. A total of 2,257 mosquitoes were morphologically identified as An. gambiae s.l. and all 224 processed for PCR were identified as An. gambiae s.s., of which 56.46% and 43.54% were M and S-forms, respectively. Both forms occurred in sympatry in all larval habitats and no S/M hybrids were detected. However, M-form larvae were in high proportion in polluted habitats than the S-form. An. gambiae s.s. was highly resistant to both deltamethrin and permethrin with mortality rates of 42.98-70.0% and 6.5-20.0% respectively. The frequency of kdr mutation was 60.5 % (n=195). This mutation occurred in both S and M-forms, but was mainly associated with the S-form (X 2 =10.92, df =1, P=0.001). Carbonate and pH were both selected in discriminant function analysis as best predictors of high proportion of M-form in the habitats. The adaptation of An. gambiae s.s. in polluted aquatic habitats coupled with occurrence of insecticide resistance is quite alarming particularly for urban malaria control and needs further exploration in a wider context. _____________________________________________________________________________________________

Impact of Urban Agriculture on the Species Distribution and Insecticide Resistance Profile of <i>Anopheles gambiae s.s.</i> and <i>Anopheles coluzzii</i> in Accra Metropolis, Ghana

“…This observation confirms work done by Yadouleton et al in Benin and Kabula et al in Ghana [4] [32] showing high insecticide resistance of A. gambiae s.l. within urban vegetable growing areas.…”

Adding a single low-dose of primaquine (0.25 mg/kg) to artemether-lumefantrine did not compromise treatment outcome of uncomplicated Plasmodium falciparum malaria in Tanzania: a randomized, single-blinded clinical trial

“…In the study area, P. falciparum is the major malaria species and Anopheles gambiae sensu stricto the main vector [7–9]. AL has been used as the first-line treatment for uncomplicated malaria since 2006.…”

Does fluoride influence oviposition of Anopheles stephensi in stored water habitats in an urban setting?

“…gambiae showed significant positive correlation of fluoride (r = 0.739, p = 0.036) with higher proportions of An. gambiae s.s. M-form in larval habitats [18]. In the present study, although fluoride showed significant weak positive correlation with immature density in general, fluoride along with TDS, EC, total hardness, chloride, and sulfate, indicated a very strong positive correlation in habitats where An.…”

“…stephensi preferred less nitrite content compared to Culex sp. and in Ghana where Anopheles gambiae preferred much less nitrite content (<0.005 mg/L) [18]. Furthermore, phosphate showed significant difference in habitats with Anopheles breeding and when co-inhabitation of Anopheles was observed with other mosquito species.…”