Sensibilité des Populations D’Aedes Aegypti des Zones Héveicoles de Dabou (Sud de la Côte d’Ivoire) aux Organophosphorés, aux Pyréthrinoïdes et au Bacillus Thuringiensis Israelensis

L’expansion de l’hévéaculture entraine une forte modification de l’environnement en Côte d’Ivoire. Aussi, plusieurs épidémies de dengue et de fièvre jaune dues Aedes aegypti ont récemment été observées en Côte d’Ivoire. Le profil de sensibilité aux insecticides d’Aedes aegypti dans ces zones d’agriculture de masse nécessitant une main d’œuvre importante est mal connu. Cette étude a établi le profil de sensibilité d’Aedes aegypti dans les zones de cultures d’hévéa de Dabou afin de mieux planifier les mesures de lutte contre le vecteur majeur des d’arbovirus. Des larves d'Aedes aegypti ont été échantillonnées en janvier 2018 dans des plantations immatures et matures d’hévéa, ainsi que dans les villages environnants aux plantations d’hévéa dans le département de Dabou. Des tests larvicides (Bacillus thuringiensis israelensis et téméphos) et adulticides (chlorpyriphos-méthyl 0.8%, malathion 0,1% et Fenitrithion 0,1%, perméthrine 0,75%, deltaméthrine 0,05%, lambdacyahalothrine 0,05%) en tube sur les générations F1 ont été réalisés conformément aux directives de l'Organisation Mondiale de la Santé (OMS). Les 3743 larves d’Aedes aegypti testées ont été toutes sensibles aux deux larvicides avec des LC50 comprises entre 7.10-3 mg/L et 9.10-3 mg/L pour le Bacillus thuringiensis israelensis et entre 6,5.10-2 mg/L et 1,2.10-1 mg/L pour le téméphos. Les LC95 respectives étaient comprises entre 2,1.10-2 mg/L et 2,4.10-2 mg/L et entre 6,5.10-2 mg/L et 1,2.10-1 mg/L. Aussi, 2400 Aedes aegypti adultes testés ont été tous sensibles aux organophosphorés (chlorpyriphos-méthyl 0.8%, malathion 0,1% et fenitrithion 0,1%) avec des mortalités comprises entre 98% et 100% et aux pyréthrinoïdes (perméthrine 0,75%, deltaméthrine 0,05%, lambdacyahalothrine 0,05%) avec des mortalités de 100%. L’étude a montré que les populations immatures et adultes d’Aedes aegypti des plantations d’hévéa et les villages environnants de la zone d’étude étaient sensibles au Bacillus thuringiensis israelensis, aux organophosphorés et aux pyréthrinoïdes. The expansion of rubber cultivation is leading to a strong modification of the environment in Côte d'Ivoire. As a result, several outbreaks of dengue and yellow fever caused by Aedes aegypti have recently been observed in Côte d'Ivoire. The insecticide susceptibility profile of Aedes aegypti in these labourintensive mass farming areas is poorly known. This study established the susceptibility profile of Aedes aegypti in the rubber growing areas of Dabou in order to better plan control measures against the major arbovirus vector. Aedes aegypti larvae were sampled in January 2018 in immature and mature rubber plantations, as well as in the villages surrounding the rubber plantations in the Dabou department. Larvicidal (Bacillus thuringiensis israelensis and temephos) and adulticidal (chlorpyriphos-methyl 0.8%, malathion 0.1% and Fenitrithion 0.1%, permethrin 0.75%, deltamethrin 0.05%, lambdacyahalothrin 0.05%) tube tests on F1 generations were carried out in accordance with the World Health Organization (WHO) guidelines. All 3743 Aedes aegypti larvae tested were sensitive to both larvicides with LC50 ranging from 7.10-3 mg/L to 9.10-3 mg/L for Bacillus thuringiensis israelensis and from 6.5.10-2 mg/L to 1.2.10-1 mg/L for temephos. The respective LC95 were between 2.1.10-2 mg/L and 2.4.10-2 mg/L and between 6.5.10-2 mg/L and 1.2.10-1 mg/L. Also, 2400 adult Aedes aegypti tested were all sensitive to organophosphates (chlorpyrifos-methyl 0.8%, malathion 0.1% and fenitrithion 0.1%) with mortalities between 98% and 100% and to pyrethroids (permethrin 0.75%, deltamethrin 0.05%, lambdacyahalothrin 0.05%) with mortalities of 100%. The study showed that immature and adult populations of Aedes aegypti in rubber plantations and surrounding villages in the study area were susceptible to Bacillus thuringiensis israelensis, organophosphates and pyrethroids

Mosquito (Diptera: Culicidae) Larval Ecology in Rubber Plantations and Rural Villages in Dabou (Côte d'Ivoire)

In Coˆte d’Ivoire, rubber cultivation has more than doubled since 2010. These mass agricultural areas require a large workforce with little information on how this environment might impact risk of mosquitoborne diseases. The objective of this study was to assess the larval ecology of mosquitoes in rubber areas of Dabou, Coˆ te d’Ivoire. From January to June 2017, an entomological survey was conducted of mature (MP) and immature (IP) rubber plantations, as well as in villages surrounded by rubber plantations (SV) and remote from rubber plantations (RV). The number and type of potential and positive breeding sites were recorded, and mosquito larval densities and diversity were estimated. Seven genera divided into 31 species including major vector such as Anopheles gambiae s.l. and Aedes aegypti were identified. A total of 1,660 waterbodies were identified with a larvae positivity rate of 63.1%. A majority of waterbodies were identified in SV (N = 875, 53.4% positivity rate), followed by MP (N = 422, 81.8% positivity rate), IP (N = 194, 72.2% positivity rate) and least in RV (N = 169, 57.4% positivity rate). The most important breeding sites for disease vectors were leaf axils in IP (N = 108, 77.1%), latex collection cups in MP (N = 332, 96.2%) and the containers abandoned in the SV (N = 242, 51.8%) as well as in the RV (N = 59, 60.8%). All these results allow us to affirm that the cultivation of rubber trees has an impact on the larval ecology by increasing the number of available sites and favoring a high larval density and diversity

Clinical Outcomes during Treatment Interruptions in Human Immunodeficiency Virus-Hepatitis B Virus Co-infected Patients from Sub-Saharan Africa

Antiretroviral treatment (ART) interruptions increase the risk of severe morbidity/mortality in human immunodeficiency virus (HIV)-infected individuals from subSaharan Africa. We aimed to determine whether the risk is further increased among HIV-hepatitis B virus (HBV) co-infected patients in this setting. In this sub-analysis of a randomized-control trial, 632 participants from Côte d'Ivoire randomized to receive continuous-ART (C-ART), structured ART interruptions of 2-months off, 4-months on (2/4-ART), and CD4-guided ART interruptions (CD4GT, interruption at 350/mm3 and reintroduction at 250/mm3) were analyzed. Incidence rates (IR) of serious HIV- and non-HIV-related morbidity were compared between patients stratified on hepatitis B surface antigen (HBsAg) status. Overall, 65 (10.3%) were HBsAg-positive, 29 (44.6%) of whom had HBV-DNA levels > 10,000 copies/mL. After a median 2.0 year (range = 0.2-3.1) followup, 3 1 serious HIV-related events occurred in 101 HIV mono-infected and 15 HIV-HBV co-infected patients (IR = 10.0 versus 13.2/100 person/years, respectively, P = 0.3), whereas the highest incidence was observed in co-infected patients with baseline HBV-replication > 10,000 copies/mL (IR = 24.0/100 person/years, P versus HIV mono-infected = 0.002). Incidence of bacterial infections was also highest in the co-infected group with HBV-replication > 10,000 copies/mL (IR = 12.9 versus 3.3/100 person/years in HIV mono-infected patients, P = 0.001). The relative effect of CD4GT or 2/4-ART versus C-ART was not different between infection groups (P for interaction = 0.4). No increase in the incidence of non-HIV-related morbidity was observed for co-infected patients (P = 0.5), even at HBV-replication levels > 10,000 copies/mL (P = 0.7). In conclusion, co-infected patients with elevated HBV-replication at ART-initiation are more susceptible to HIV-related morbidity, especially invasive bacterial diseases, during treatment interruption