scholarly journals Anophelesbionomics, insecticide resistance mechanisms and malaria transmission in the Korhogo area, northern Côte d’Ivoire: a pre-intervention study

2019 ◽  
Author(s):  
Barnabas Zogo ◽  
Dieudonné Diloma Soma ◽  
Bertin N’Cho Tchiekoi ◽  
Anthony Somé ◽  
Ludovic P. Ahoua Alou ◽  
...  

AbstractBackgroundA better understanding of malaria transmission at a local scale is essential for developing and implementing effective control strategies. In the frame of a randomized control trial, we aimed to provide an updated description of malaria transmission in the Korhogo area, northern Côte d’Ivoire, and to get baseline data for the trial.MethodsWe performed Human Landing Collections in 26 villages in the Korhogo area during the rainy season (September-October 2016, April-May 2017) and the dry season (November-December 2016, February-March 2017). We used Polymerase chain reaction techniques to ascertain the species of theAn. gambiaecomplex,Plasmodium spsporozoite infection and insecticide resistance mechanisms in a subset ofAnophelesvectors.ResultsAnopheles gambiae s.l. was the predominant malaria vector in the Korhogo area. Overall, more vectors were collected outdoors than indoors (P < 0.001). Of the 774An. gambiae s.l. tested in the laboratory, 89.65% wereAn. gambiae s.s. and 10.35% wereAn. coluzzii. The frequencies of thekdrallele were very high inAn. gambiae s.s. but theace-1allele was found at moderate frequencies. An unprotected individual living in the Korhogo area received an average of 9.04, 0.63, 0.06 and 0.12 infected bites per night in September-October, November-December, February-March, and April-May, respectively.ConclusionsThe intensity of malaria transmission is extremely high in the Korhogo area, especially during the rainy season. Malaria control in highly endemic areas such as Korhogo needs to be strengthened with complementary tools in order to reduce the burden of the disease.

Parasite ◽  
2019 ◽  
Vol 26 ◽  
pp. 40 ◽  
Author(s):  
Barnabas Zogo ◽  
Dieudonné Diloma Soma ◽  
Bertin N’Cho Tchiekoi ◽  
Anthony Somé ◽  
Ludovic P. Ahoua Alou ◽  
...  

A better understanding of malaria transmission at a local scale is essential for developing and implementing effective control strategies. In the framework of a randomized controlled trial (RCT), we aimed to provide an updated description of malaria transmission in the Korhogo area, northern Côte d’Ivoire, and to obtain baseline data for the trial. We performed human landing collections (HLCs) in 26 villages in the Korhogo area during the rainy season (September–October 2016, April–May 2017) and the dry season (November–December 2016, February–March 2017). We used PCR techniques to ascertain the species of the Anopheles gambiae complex, Plasmodium falciparum sporozoite infection, and insecticide resistance mechanisms in a subset of Anopheles vectors. Anopheles gambiae s.l. was the predominant malaria vector in the Korhogo area. Overall, more vectors were collected outdoors than indoors (p < 0.001). Of the 774 An. gambiae s.l. tested in the laboratory, 89.65% were An. gambiae s.s. and 10.35% were An. coluzzii. The frequencies of the kdr allele were very high in An. gambiae s.s. but the ace-1 allele was found at moderate frequencies. An unprotected individual living in the Korhogo area received an average of 9.04, 0.63, 0.06 and 0.12 infected bites per night in September–October, November–December, February–March, and April–May, respectively. These results demonstrate that the intensity of malaria transmission is extremely high in the Korhogo area, especially during the rainy season. Malaria control in highly endemic areas such as Korhogo needs to be strengthened with complementary tools in order to reduce the burden of the disease.


2016 ◽  
Vol 11 (1) ◽  
pp. 18-25
Author(s):  
Ouattara Genefol ◽  
Camara Brahima ◽  
Bomisso Edson Lezi ◽  
Cherif Mamadou ◽  
Sorho Fatogoma ◽  
...  

2019 ◽  
Vol 41.2 ◽  
pp. 6926-6939
Author(s):  
NIAMIEN Coffi Jean Magloire ◽  
KONAN Ekoun Michaël ◽  
ODOUKPE Kadio Saint Guillaume ◽  
YAOKOKORE-BEIBRO Kouassi Hilaire ◽  
N’GORAN Kouakou Eliézer

Les oiseaux rendent d’importants services écologiques nécessaires au bien-être de l’homme. En Côte d’Ivoire, l’essentiel des études ornithologiques se sont déroulées au sud, et accessoirement au centre et au centre-ouest. En outre, très peu de travaux ont porté sur les zones humides. La ville de Korhogo abrite des barrages à vocation agro-pastorale qui n’ont été l’objet d’aucune étude. Pour combler ce manque de connaissance, une étude a été menée de février 2016 à janvier 2017. L’objectif de ce travail est d’évaluer la richesse spécifique et de déterminer l’influence des saisons sur la distribution qualitative de la communauté des oiseaux du barrage urbain de Koko dans la commune de Korhogo. Pour ce faire, des observations directes, utilisant la méthode des transects ponctuée d’arrêts d’environ 15 minutes, ont été effectuées. Les résultats indiquent que cette communauté est constituée de 63 espèces d’oiseaux appartenant à 32 familles et regroupées en 14 ordres. Globalement, l’ordre des Passériformes et la famille des Ardeidae sont les mieux représentés. Du point de vue de leur statut biogéographique, les espèces résidentes (37 individus : 59 %) et accidentelles (23 individus : 36,51%) sont majoritaires. Le plus grand nombre d’espèces a été observé en saison des pluies (52 individus : 82,54%). Sept espèces ont été spécifiques de la saison sèche alors que trois espèces sont caractéristiques de la saison des pluies. Les espèces résidentes ont été les nombreuses en toute saison. Au niveau structural, les espèces accessoires, les espèces assez-fréquentes et les espèces fréquentes ont été les mieux représentées en saison sèche tandis que les espèces assez-fréquentes ont été majoritaires en saison des pluies. Cette étude confirme la distribution des communautés des oiseaux selon les saisons. ABSTRACT Birds provide important ecosystem services necessary for human well-being. In Côte d'Ivoire, ornithological studies were carried out in the south, central and central-west. In addition, very little work has been done on wetlands. The Commune of Korhogo is home to agro-pastoral dams that have not been studied. To fill in this gap of information, a study was conducted from February 2016 to January 2017. The aim of this study was to assess the specific richness and to examine the effect of seasons on the qualitative distribution of the Koko urban dam birds’ community. Direct observations using the method of line transects with a 15 minutes points were carried out. Results show that this community consists of 63 species of birds belonging to 32 families and grouped in 14 orders. Globally, the order of the Passeriformes and the family of Ardeidae were the best represented. In terms of their biogeographical status, resident species (37 individuals: 59%) and accidental species (23 individuals: 36.51%) were dominant. The high number of bird species was observed during the rainy season (52 individuals: 82.54%). Seven species were specific to the dry season while three species are characteristic of the rainy season. Resident species were numerous in all seasons. The accessory and relatively frequent species have been the most abundant during the dry season while the fairly frequent species were predominant in the rainy season. This study confirms the distribution of bird communities according to the seasons.


2010 ◽  
Vol 104 (2) ◽  
pp. 109-121 ◽  
Author(s):  
B. G. Koudou ◽  
M. Doumbia ◽  
N. Janmohamed ◽  
A. B. Tschannen ◽  
M. Tanner ◽  
...  

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
A Hounsa ◽  
D Yao ◽  
A R Attia ◽  
M Gokpéya ◽  
K J Sackou ◽  
...  

Abstract Background In malaria-endemic areas, asymptomatic carriers are a reservoir of parasites that contribue to the persistence of malaria transmission. In Côte d’Ivoire, this situation is poorly documented. The objective of our study was to assess the frequency and socio-environmental factors associated with asymptomatic malaria in the town of Assuefry, located in the northeast of Côte d’Ivoire, a region where malaria prevalence remains high. Methods A cross-sectional study in two stages was conducted from October to December 2018, first at the Urban Health Center (UHC) in Assuefry and then in the households. The sample size calculated for patients was 162 extrapolated to 201 people. All persons received at the CSU who had clinical symptoms of malaria and a positive Rapid Diagnostic Test (RDT) were included. In the households of these index subjects, a follow-up survey allowed active RDT screening for malaria among all household members with no clinical signs of malaria. The socio-environmental factors taken into account were: the area of residence (urban or peri-urban), domestic animals husbandry, water storage at home, nearby garbage dump, wastewater collection and disposal system, type of housing and number of people in the household. Results The frequency of asymptomatic malaria was 341 (38.8%) out of 879 household members visited. Both female and male gender was concerned (51% vs. 49%). The 5 to 25 years old group concentrated nearly 82% of all cases. Only domestic animals husbandry was associated with asymptomatic malaria at the household level (p = 0.021). Conclusions The high frequency of asymptomatic malaria found in this study is a challenge for the National Malaria Control Program in Côte d’Ivoire. This should be taken into account while organizing control strategies. Key messages The frequency of asymptomatic malaria in Côte d’Ivoire is high. Control strategies must take into account in the guidelines the challenges of detecting and treating asymptomatic malaria. For the judicious use of antimalarial drugs, any subject with a positive RDT without clinical signs of malaria should receive a ‘Drop - Thick’ before treatment.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Welbeck A. Oumbouke ◽  
Patricia Pignatelli ◽  
Antoine M. G. Barreaux ◽  
Innocent Z. Tia ◽  
Alphonsine A. Koffi ◽  
...  

Abstract Routine monitoring of occurrence, levels and mechanisms of insecticide resistance informs effective management strategies, and should be used to assess the effect of new tools on resistance. As part of a cluster randomised controlled trial evaluating a novel insecticide-based intervention in central Côte d’Ivoire, we assessed resistance and its underlying mechanisms in Anopheles gambiae populations from a subset of trial villages. Resistance to multiple insecticides in An. gambiae s.s. and An. coluzzii was detected across villages, with dose–response assays demonstrating extremely high resistance intensity to the pyrethroid deltamethrin (> 1,500-fold), and mortality following exposure to pyrethroid-treated bednets was low (< 30% mortality in cone bioassays). The 1014F kdr mutation was almost fixed (≥ 90%) in all villages but the 1575Y kdr-amplifying mutation was relatively rare (< 15%). The carbamate and organophosphate resistance-associated Ace-1 G119S mutation was also detected at moderate frequencies (22–43%). Transcriptome analysis identified overexpression of P450 genes known to confer pyrethroid resistance (Cyp9K1, Cyp6P3, and Cyp6M2), and also a carboxylesterase (COEAE1F) as major candidates. Cyp6P3 expression was high but variable (up to 33-fold) and correlated positively with deltamethrin resistance intensity across villages (r2 = 0.78, P = 0.02). Tools and strategies to mitigate the extreme and multiple resistance provided by these mechanisms are required in this area to avoid future control failures.


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