scholarly journals Environmental factors associated with the malaria vectors Anopheles gambiae and Anopheles funestus in Kenya

2009 ◽  
Vol 8 (1) ◽  
Author(s):  
Louise A Kelly-Hope ◽  
Janet Hemingway ◽  
F Ellis McKenzie
Keyword(s):  
Environmental Factors ◽  
Anopheles Gambiae ◽  
Anopheles Funestus ◽  
Malaria Vectors ◽  
Factors Associated

scholarly journals Environmental Factors Associated with the Distribution of Anopheles gambiae s.s in Ghana; an Important Vector of Lymphatic Filariasis and Malaria

PLoS ONE ◽  
2010 ◽  
Vol 5 (3) ◽  
pp. e9927 ◽  
Author(s):  
Dziedzom de Souza ◽  
Louise Kelly-Hope ◽  
Bernard Lawson ◽  
Michael Wilson ◽  
Daniel Boakye
Keyword(s):  
Environmental Factors ◽  
Anopheles Gambiae ◽  
Lymphatic Filariasis ◽  
Anopheles Gambiae S.S ◽  
Factors Associated

scholarly journals 16S rRNA Gene-Based Identification of Midgut Bacteria from Field-Caught Anopheles gambiae Sensu Lato and A. funestus Mosquitoes Reveals New Species Related to Known Insect Symbionts

2005 ◽  
Vol 71 (11) ◽  
pp. 7217-7223 ◽  
Author(s):  
Jenny M. Lindh ◽  
Olle Terenius ◽  
Ingrid Faye
Keyword(s):  
16S Rrna ◽  
Anopheles Gambiae ◽  
Bacterial Species ◽  
Anopheles Funestus ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Malaria Vectors ◽  
Rrna Gene ◽  
Species Determination ◽  
Insect Symbionts

ABSTRACT Field-collected mosquitoes of the two main malaria vectors in Africa, Anopheles gambiae sensu lato and Anopheles funestus, were screened for their midgut bacterial contents. The midgut from each blood-fed mosquito was screened with two different detection pathways, one culture independent and one culture dependent. Bacterial species determination was achieved by sequence analysis of 16S rRNA genes. Altogether, 16 species from 14 genera were identified, 8 by each method. Interestingly, several of the bacteria identified are related to bacteria known to be symbionts in other insects. One isolate, Nocardia corynebacterioides, is a relative of the symbiont found in the vector for Chagas' disease that has been proven useful as a paratransgenic bacterium. Another isolate is a novel species within the γ-proteobacteria that could not be phylogenetically placed within any of the known orders in the class but is close to a group of insect symbionts. Bacteria representing three intracellular genera were identified, among them the first identifications of Anaplasma species from mosquitoes and a new mosquito-Spiroplasma association. The isolates will be further investigated for their suitability for a paratransgenic Anopheles mosquito.

scholarly journals Entomological Indicators of Malaria Transmission Prior to a Cluster Randomised Controlled Trial of a “Lethal House Lure” Intervention in Central Côte D’Ivoire

2021 ◽  
Author(s):  
Rosine Zlanneu Wolie ◽  
Alphonsine A. Koffi ◽  
Lesley Ayuk-Taylor ◽  
Ludovic P. Ahoua Alou ◽  
Eleanore D. Sternberg ◽  
...  
Keyword(s):  
Anopheles Gambiae ◽  
Malaria Transmission ◽  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Controlled Trial ◽  
Anopheles Funestus ◽  
Malaria Vectors ◽  
Cote D’Ivoire ◽  
Côte D'ivoire ◽  
Indoor And Outdoor

Abstract Background: A study was conducted prior to implementing a cluster randomised controlled trial (CRT) of a lethal house lure strategy in central Côte d’Ivoire and aimed to provide baseline information on malaria vectors in 40 village clusters. Methods: Human landing catches (HLC) was performed between November-December 2016, capturing mosquitoes indoor and outdoor between 18.00-08.00. Mosquitoes were processed for entomological indicators of malaria transmission (human biting rates, parity rates, sporozoite infection rates and the entomological inoculation rates (EIR)). Species composition and allelic frequencies of Kdr-w and Ace-1R mutations were also investigated within the Anopheles gambiae complex. Results: Overall, 15,632 mosquitoes were captured. Anopheles gambiae s.l. and Anopheles funestus were the two malaria vectors found during the survey period, with predominance for Anopheles gambiae s.l. (66.2%) compared to Anopheles funestus (10.3%). The mean biting rate for An. gambiae s.l. was almost 5 times higher than that for An. funestus s.l.(19.8 bites per person per night for An. gambiae s. l. vs 4.3 bites per person per night for An. funestus s. l.) and this was evident indoor and outdoor. An. funestus was more competent to transmit malaria parasites in the study area, despite relatively lower number tested for sporozoite index (1.6% (1,373) for An. gambiae vs 4.7 % (722) for An. funestus s.l.). There was no significant difference between the proportion infected outdoor and indoor for An. gambiae s.l. (1.6% vs 1.5%; OR=1.11[0.65-1.9]; P=0.676), but for An. funestus, more mosquitoes were infected outdoor (6.4%) than indoor (3.5%) (OR=1.86 [1.07-3.23]; P=0.0249). The majority of both infected vectors with malaria parasites harboured P. falciparum (90.6% for An. gambiae s. l. and 97, 8% for An. funestus s. l.). The EIR for both vectors (0.43 infected bites per night) were similar and there were no significant differences for transmission occurring outdoor and indoor for both species. Of the An. gambiae s.l. analysed, only An. gambiae (14.1%) and An. coluzzii (85.9%) were found. The allelic frequencies of Kdr and Ace-1R were higher in An. gambiae (0.97 for Kdr and 0.19 for Ace-1R) than in An. coluzzii (0.86 for Kdr and 0.10 for Ace-1R) (P<0.001).Conclusion: Despite universal coverage of long-lasting insecticidal nets (LLINs) in the area, there was an abundance of malaria vectors in the study in area in central Côte d’Ivoire, specifically highly resistant An. gambiae s.l. as well as An. funestus s.l.. The malaria sporozoite rate was higher in An. funestus s.l than An. gambiae s.l.. but EIR rates in these two species were similarly high, both indoor and outdoor. Novel tools or strategies are urgently needed to further reduce malaria transmission in this area.

scholarly journals Multimodal Pyrethroid Resistance in Malaria Vectors, Anopheles gambiae s.s., Anopheles arabiensis, and Anopheles funestus s.s. in Western Kenya

PLoS ONE ◽  
2011 ◽  
Vol 6 (8) ◽  
pp. e22574 ◽  
Author(s):  
Hitoshi Kawada ◽  
Gabriel O. Dida ◽  
Kazunori Ohashi ◽  
Osamu Komagata ◽  
Shinji Kasai ◽  
...  
Keyword(s):  
Anopheles Gambiae ◽  
Anopheles Arabiensis ◽  
Pyrethroid Resistance ◽  
Anopheles Funestus ◽  
Malaria Vectors ◽  
Anopheles Gambiae S.S ◽  
Western Kenya

The response of Anopheles gambiae s.l. and A. funestus (Diptera: Culicidae) to tents baited with human odour or carbon dioxide in Tanzania

1997 ◽  
Vol 87 (2) ◽  
pp. 173-178 ◽  
Author(s):  
L.E.G. Mboera ◽  
B.G.J. Knols ◽  
W. Takken ◽  
A. della Torre
Keyword(s):  
Carbon Dioxide ◽  
Anopheles Gambiae ◽  
Light Trap ◽  
Anopheles Funestus ◽  
Carbon Dioxide Concentration ◽  
Fold Increase ◽  
Field Studies ◽  
Malaria Vectors ◽  
Bed Net ◽  
Human Odour

AbstractField studies on the response of Anopheles gambiae s.l. Giles and Anopheles funestus Giles to tents baited with human odour or carbon dioxide were conducted in south-east Tanzania. Two exit traps and a CDC miniature light trap set beside a bed net were used to sample mosquitoes that entered the tent. Human odour, pumped from an underground pit into a bed net attracted a similar number of mosquitoes as a bed net occupied by a human male. Significantly fewer mosquitoes were caught in a tent into which carbon dioxide (300 ml min-1) was pumped than in a human-odour baited tent (9 and 27% for A. gambiae s.l. and A. funestus respectively). A five-fold increase of the carbon dioxide concentration (to 1500 ml min-1) did not increase the catches of A. gambiae s.l. whereas those of A. funestus were increased to 69% of the catches by human odour. Species identifications of A. gambiae s.l. catches showed that A. arabiensis Patton prevailed and that the proportions of A. arabiensis/A. gambiae s.s. did not differ between treatments. It is concluded that in the indoor situation described, human odour other than carbon dioxide is the principal cue to which these malaria vectors are attracted and that the physical presence of a host and carbon dioxide, when used as a kairomone on its own, accounts for only a minor part of the overall attractiveness of man, particularly for A. gambiae s.l.

scholarly journals Elevated Plasmodium sporozoite infection and multiple insecticide resistance in the principal malaria vectors Anopheles funestus and Anopheles gambiae in a forested locality close to the Yaoundé airport, Cameroon

2020 ◽  
Vol 5 ◽  
pp. 146
Author(s):  
Francis N. Nkemngo ◽  
Leon M. J. Mugenzi ◽  
Ebai Terence ◽  
Abdoulaye Niang ◽  
Murielle J. Wondji ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Anopheles Gambiae ◽  
Transcriptional Profiling ◽  
Anopheles Funestus ◽  
Abundant Species ◽  
Resistance Mechanisms ◽  
Malaria Vectors ◽  
Resistance Allele ◽  
Sporozoite Rate ◽  
Forested Areas

Background: Reducing the burden of malaria requires better understanding of vector populations, particularly in forested regions where the incidence remains elevated. Here, we characterized malaria vectors in a locality near the Yaoundé international airport, Cameroon, including species composition, abundance, Plasmodium infection rate, insecticide resistance profiles and underlying resistance mechanisms. Methods: Blood-fed adult mosquitoes resting indoors were aspirated from houses in April 2019 at Elende, a village located 2 km from the Yaoundé-Nsimalen airport. Female mosquitoes were forced to lay eggs to generate F1 adult progeny. Bioassays were performed to assess resistance profile to insecticides. The threshold of insecticide susceptibility was defined above 98% mortality rate and mortality rates below 90% were indicative of confirmed insecticide resistance. Furthermore, the molecular basis of resistance and Plasmodium infection rates were investigated. Results: Anopheles funestus s.s. was most abundant species in Elende (85%) followed by Anopheles gambiae s.s. (15%) with both having a similar sporozoite rate. Both species exhibited high levels of resistance to pyrethroids (<40% mortality). An. gambiae s.s. was also resistant to DDT (9.9% mortality) and bendiocarb (54% mortality) while susceptible to organophosphate. An. funestus s.s. was resistant to dieldrin (1% mortality), DDT (86% mortality) but susceptible to carbamates and organophosphates. The L119F-GSTe2 resistance allele (8%) and G119S ace-1 resistance allele (15%) were detected in An. funestus s.s. and An. gambiae s.s., respectively. Furthermore, the high pyrethroid/DDT resistances in An. gambiae s.s. corresponded with an increase frequency of 1014F kdr allele (95%). Transcriptional profiling of candidate cytochrome P450 genes reveals the over-expression of CYP6P5, CYP6P9a and CYP6P9b. Conclusion: The resistance to multiple insecticide classes observed in these vector populations alongside the high Plasmodium sporozoite rate highlights the challenges that vector control programs encounter in sustaining the regular benefits of contemporary insecticide-based control interventions in forested areas.

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