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IntroductionMaternal and infant morbidity and mortality remain high in sub-Saharan Africa. However, actions to strengthen postpartum care are still weak and mainly limited to health facilities (HFs). In Kaya health district, Burkina Faso, community health workers (CHWs) were involved in mother and child care during the 1st year postpartum through home visits, outreach sessions and accompanying mothers to health facilities. The aim of this study was to assess the contribution of CHWs to postpartum women's attendance at the health facilities.MethodsWe conducted an effect assessment using Mayne and Lemire's contribution analysis framework. Qualitative and quantitative data were collected through project documents review and individual semi-structured interviews with key-informants.ResultsAll the participants interviewed acknowledged that the number of women, who came to postpartum care, had increased since the implementation of the project activities. Postpartum consultation rates within the 1st week postpartum increased from 29% in 2011 to 80% in 2015 and from 19 to 50% within 6 weeks. Others interventions such as Performance based financing, Save The Children nutritional project and the health services component of Missed Opportunities in Mother and Infant Health (MOMI) were the alternative explanations.ConclusionsCHWs involvement in women care contributed to improve their adherence to postpartum consultations in Kaya health district.

Abstract Background Exclusive breastfeeding is critical for infant survival and development. However, the rate of exclusive breastfeeding in the first 6 months of life is low in sub-Saharan Africa. With the current trend in breastfeeding rates in many countries including in Guinea, the World Health Assembly target of at least 50% of children aged less than 6 months being exclusively breastfeed by 2025 is likely to be compromised and lives a numerous infant that are be at risk. The objective of this study was to identify the individual and contextual determinants of the practice of Exclusive Breastfeeding (EBF) in Guinea. Method We conducted a secondary analysis of data from the 2018 Guinea Demographic and Health Survey (DHS). The study population consisted of women who gave birth between the ages of 15 and 49. Our sample consisted of women who had their last birth six (06) months prior to collection. The enumeration areas were our second level. A multilevel logistic regression was performed using Stata version 15.1 software. Three statistical models were implemented: The final model was obtained using the bottom-up step-by-step method. The intra-class correlation coefficient was calculated. Results On the 851 women included in our study, 33% reported having exclusively breastfed during the first 6 months of life of their children. After a multivariate analysis, the variables associated with exclusive breastfeeding are: children aged 2–3 months (OR = 0.53 CI95% = [0.36–0.79]) and children aged 4–5 months (OR = 0.23 IC95% = [0.14–0.36]), women in the Faranah area (OR = 2.69 IC95% = [1.21–5.94]) and those in Mamou (OR = 2.27 IC95% = [1.00–5.94]), women who gave birth in a health facility (OR = 1.94 IC95% = [1.34–2.80]) and women living in polygamous households (OR = 0.68 IC95% = [0.48–0.98]). Conclusion The practice of exclusive breastfeeding remains low in Guinea. For the achievement of Sustainable Development Goals, particularly the improvement of exclusive breastfeeding practices, the individual and contextual determinants identified in this study should be taken into consideration in policies and programmes.

Abstract Background The effective use of contraception among adolescents and young women can reduce the risk of unintended pregnancies. However, the prevalence of contraceptive use remains low in this age group. The objective of this study was to estimate the rate of contraceptive method discontinuation among adolescents and young women and to identify its associated factors in Burkina Faso, Mali, and Niger. Method This was a secondary analysis of data from Demographic and Health Surveys of Burkina Faso (2010), Mali (2012–2013), and Niger (2012). The dependent variable was the time to discontinuation of contraceptive methods. Independent variables were represented by sociodemographic, socioeconomic, and cultural characteristics. Mixed-effects survival analysis with proportional hazards was used to identify the predictors. Results A total of 2,264 adolescents and young women aged 15 to 24 years were included in this analysis, comprising 1,100 in Burkina Faso, 491 in Mali, and 673 in Niger. Over the last five years, the overall contraceptive discontinuation rate was 68.7% (50.1% in Burkina Faso, 59.6% in Mali, and 96.8% in Niger). At the individual level, in Burkina Faso, occupation (aHR = 0.33), number of living children (aHR = 2.17), marital status (aHR = 2.93), and region (aHR = 0.54) were associated with contraceptive discontinuation. Except for education and marital status, we found the same factors in Mali. In Niger, a women's education level (aHR = 1.47) and her partner (aHR = 0.52) were associated with discontinuation. At the community level, the region of origin was associated with discontinuation of contraceptive methods. Conclusion Most adolescents and young women experienced at least one episode of discontinuation. Discontinuation of contraceptive methods is associated with the level of education, occupation, number of children, marital status, and desire for children with the spouse. Promotion of contraceptive interventions should target adolescents, young women, and their partners, as well as those with a low education level or in a union.

SYNOPSIS: Generally, there are disparities in the availability and utilization of postabortion care services within the different regions at the national level in Burkina Faso, Cote d’Ivoire, and Guinea and between the 3 countries. Access to postabortion care at the primary level must be improved and the adoption of family planning when providing postabortion care. Unsafe abortion remains one of the leading causes of maternal mortality in sub-Sahara Africa, with relatively poor access to quality postabortion care (PAC) services. This study evaluated the quantity and distribution as well as the utilization of PAC services in Burkina Faso, Cote d’Ivoire, and Guinea. We conducted a secondary data analysis using the most recent EmONC surveys in the 3 countries between 2016 and 2017. We used PAC signal functions approach to assess facilities’ capacity to provide basic PAC at both primary and referral level of care and comprehensive PAC at the referral level. We illustrated population coverage of PAC services based on the WHO benchmark, and then assessed the utilization of PAC services. Basic PAC capacity at primary level was low (36.6%), ranging from 16.2% in Burkina Faso to 36% in Cote d’Ivoire. About 82.0% of hospitals could provide comprehensive PAC. There were disparities in the geographical distribution of PAC services at both national and subnational levels. Abortion complications represented 16.2% of all obstetric emergencies, and uptake of PAC modern contraceptive was low (37.1%) in all countries. There is a need to focus on access to PAC at the primary level of care in the 3 countries.

Correct timing of phenology is crucial for the survival and growth of species in arid areas with long dry seasons. Nevertheless, knowledge on genetic variation and adaptive patterns in phenology in deciduous African dryland species is limited. Here we study the variation in phenology of diploid and polypoid A. senegal trees from rangewide populations growing in a common garden trial in Senegal and test correlations between population phenology and climate at the site of origin. The leafing, flowering and fruiting phenology was monitored during 17 months and compared to detailed observations of the rainfall in the common garden during the period. We found that A. senegal trees in general started development of leaves prior to the beginning of the rainy season with flowering and fruiting initiation occurring during the rainy season. The results lead us to conclude that is was not the rain per se that initiated leaf development. We also conclude that phenology in A. senegal is under genetic control, because significant differences could be observed among populations and ploidy levels when grown at the same site. In general, early leaf flushing trees had a longer growing period and performed better in terms of growth at the tested site and the results thus support that leaf phenology influence fitness. We further found that differences among trees in phenology seem to be associated with differences in climate at their site of origin, because the timing of leaf development in the common garden and the timing of the rainy season at the site of origin was significantly correlated for the diploid trees (not for tetraploids). However, it was diploid trees from sites with a late arriving rainy season that developed leaves earliest in the year. The environmental cues that control leafing phenology and the associated physiological mechanisms therefore still need to be identified in order to understand how the variation among populations has evolved, its relationship to local adaptation and the implication for smart transfer of seed sources as mean to mitigate changing growing conditions related to global warming.

INTRODUCTION: Les technologies mobiles en santé sont de plus en plus utilisées comme solutions innovantes pour améliorer les services de soins prénatals (SPN) dans les soins de première ligne. Cette étude a évalué l´acceptabilité et la satisfaction de l´utilisation du système Pregnancy and Newborn Diagnostic Assessment PANDA lors des SPN au Burkina Faso. METHODES: une étude transversale utilisant une approche mixte a été menée auprès de 35 utilisatrices des SPN et de 35 agents de santé dans le district sanitaire de Koupéla, dans la région du Centre-Est du Burkina Faso en septembre 2017. Des entretiens et 4 focus groups ont été réalisés auprès des utilisatrices des SPN et des d´entretiens semi-structurés auprès des professionnels de soin. L´analyse des données quantitatives a été effectuée avec le logitiel SPSS et les données qualitatives à l´aide d´une analyse thématique avec Nvivo 10. RESULTATS: le système PANDA a été très bien accepté et très apprécié par les utilisatrices et les prestataires de soins. Les motifs de satisfaction chez les utilisatrices étaient l´amélioration des échanges avec les prestataires de soin et l´accès à des soins de meilleure qualité à moindre coût. Les agents de santé ont apprécié la pertinence du système PANDA et l´amélioration des prestations fournies, du suivi et de la prise en charge des femmes enceintes. CONCLUSION: le système PANDA est très bien accepté et apprécié au niveau des soins primaires aussi bien par les prestataires de soins que par les utilisatrices de services de soins prénataux au Burkina Faso.

Sudden adult death is an instantaneous or rapid death of natural, unexpected or unexpected origin. As a public health issue, the global incidence of sudden death would be 20100 per 100,000 population.The main objective of our study was to assess the incidence of sudden death in Dakar. The specific objectives were to establish the epidemiological profile of sudden death, identify the circumstances of its occurrence and the medical and surgical causes, and identify the factors associated with sudden deaths from cardiovascular causes.It is an observational, descriptive, retrospective study covering a period of 5 years, from January 1, 2014 to December 31, 2018. Included in the study were all records of adults (18 years of age and over) who died suddenly, in a health facility or outside it and were autopsied in the morgues of Aristide le Dantec Hospital (HALD) and Idrissa Pouye General Hospital (HOGIP).We found 1133 cases of sudden adult death, or 28 % of autopsies. The annual average was 226.6 cases. Our series consisted of 918 men and 215 women, for a sex ratio of 3.27. The sudden death of the adult was predominantly cardiovascular in origin with 561 cases or 49.5 %. The MI occurred on average at 51.95 years of age with 164 males (84.5 % of MIs) and 30 females (15.5 % of MIs). With regard to pulmonary causes, pulmonary tuberculosis was the leading cause of pulmonary origin with 66 cases or 26.2 %. For digestive causes, generalized acute peritonitis (GAP) was the most frequent cause with 29 cases (38.7 %).The prevention of sudden death is essentially based on cardiovascular disease treatment and prevention. The African context has to deal with weak health promotion, a failure of pre-hospital care and the daily difficulties of hospital care.

e le tabac pendant l�hospitalisation. Apres un suivi de 3 mois, 45% des patients ont repris le tabac, 65% a 6 mois et 85% a 12 mois. CONCLUSION: Le tabagisme est assez frequent chez les patients senegalais presentant un infarctus du myocarde. Le taux de sevrage tabagique a court et moyen termes est faible. Le sevrage tabagique devrait alors constituer un objectif privilegie dans la prevention des maladies cardio-vasculaires.

Abstract Background The growing development of pyrethroid resistance constitutes a serious threat to malaria control programmes and if measures are not taken in time, resistance may compromise control efforts in the foreseeable future. Prior to Long Lasting Insecticidal Nets (LLINs) distribution in Eastern Cote d’Ivoire, we conducted bioassays to inform the National Malaria Control Programme of the resistance status of the main malaria vector, Anopheles gambiae s. s. and the need for close surveillance of resistance. Methods Larvae of An. gambiae s. s. were collected in two areas of Adzopé (Port-Bouët and Tsassodji) and reared to adults. WHO susceptibility tests with impregnated filter papers were carried out to detect resistance to three pyrethroids commonly used to develop LLINs: permethrin 1%, deltamethrin 0.05% and lambda-cyhalothrin 0.05%. Molecular assays were conducted to detect M and S forms and the L1014F kdr allele in individual mosquitoes. Results Resistance, at various degrees was detected in both areas of Adzopé. Overall, populations of An. gambiae at both sites surveyed showed equivalent frequency of the L1014F kdr allele (0.67) but for all tested pyrethroids, there were significantly higher survival rates for mosquitoes from Tsassodji (32–58%) than those from Port-Bouët (3–32%) (p kdr alone. During the survey period (May–June) in this forested area of Côte d’Ivoire, An. gambiae s. s. found were exclusively of the M form and were apparently selected for pyrethroid resistance through agricultural and household usage of insecticides. Conclusion Prior to LLINs scaling up in Eastern Côte d’Ivoire, resistance was largely present at various levels in An. gambiae. Underlying mechanisms included the high frequency of the L1014F kdr mutation and other unidentified components, probably metabolic detoxifiers. Their impact on the efficacy of the planned strategy (LLINs) in the area should be investigated alongside careful monitoring of the trend in that resistance over time. The need for alternative insecticides to supplement or replace pyrethroids on nets must be stressed.

Abstract Background At Yaokoffikro field site near Bouaké, in central Côte d'Ivoire, a group of experimental huts built in 1996 served over many years for the evaluation of insecticides against highly resistant mosquitoes. Breeding sites of mosquitoes and selection pressure in the area were maintained by local farming practices until a war broke out in September 2002. Six years after the crisis, we conducted bioassays and biochemical analysis to update the resistance status of Anopheles gambiae s.s. populations and detect other potential mechanisms of resistance that might have evolved. Methods An. gambiae s.s. larvae from Yaokoffikro were collected in breeding sites and reared to adults. Resistance status of this population to insecticides was assessed using WHO bioassay test kits for adult mosquitoes with seven insecticides: two pyrethroids, a pseudo-pyrethroid, an organochloride, two carbamates and an organophosphate. Molecular and biochemical assays were carried out to identify the L1014F kdr and ace-1R alleles in individual mosquitoes and to detect potential increase in mixed function oxidases (MFO), non-specific esterases (NSE) and glutathione S-transferases (GST) activity. Results High pyrethroids, DDT and carbamate resistance was confirmed in An. gambiae s.s. populations from Yaokoffikro. Mortality rates were less than 70% with pyrethroids and etofenprox, 12% with DDT, and less than 22% with the carbamates. Tolerance to fenitrothion was observed, with 95% mortality after 24 h. PCR analysis of samples from the site showed high allelic frequency of the L1014F kdr (0.94) and the ace-1R (0.50) as before the crisis. In addition, increased activity of NSE, GST and to a lesser extent MFO was found relative to the reference strain Kisumu. This was the first report detecting enhanced activity of these enzymes in An. gambiae s.s from Yaokoffikro, which could have serious implications in detoxification of insecticides. Their specific roles in resistance should be investigated using additional tools. Conclusion The insecticide resistance profile at Yaokoffikro appears multifactorial. The site presents a unique opportunity to evaluate its impact on the protective efficacy of insecticidal products as well as new tools to manage these complex mechanisms. It calls for innovative research on the behaviour of the local vector, its biology and genetics that drive resistance.

Abstract Background The spread of pyrethroid resistance in Anopheles gambiae s.s. is a critical issue for malaria vector control based on the use of insecticide-treated nets. Carbamates and organophosphates insecticides are regarded as alternatives or supplements to pyrethroids used in nets treatment. It is, therefore, essential to investigate on the susceptibility of pyrethroid resistant populations of An. gambiae s.s. to these alternative products. Methods In September 2004, a cross sectional survey was conducted in six localities in Côte d'Ivoire: Toumbokro, Yamoussoukro, Toumodi in the Southern Guinea savannah, Tiassalé in semi-deciduous forest, then Nieky and Abidjan in evergreen forest area. An. gambiae populations from these localities were previously reported to be highly resistant to pyrethroids insecticides. Anopheline larvae were collected from the field and reared to adults. Resistance/susceptibility to carbamates (0.4% carbosulfan, 0.1% propoxur) and organophosphates (0.4% chlorpyrifos-methyl, 1% fenitrothion) was assessed using WHO bioassay test kits for adult mosquitoes. Then, PCR assays were run to determine the molecular forms (M) and (S), as well as phenotypes for insensitive acetylcholinesterase (AChE1) due to G119S mutation. Results Bioassays showed carbamates (carbosulfan and propoxur) resistance in all tested populations of An. gambiae s.s. In addition, two out of the six tested populations (Toumodi and Tiassalé) were also resistant to organophosphates (mortality rates ranged from 29.5% to 93.3%). The M-form was predominant in tested samples (91.8%). M and S molecular forms were sympatric at two localities but no M/S hybrids were detected. The highest proportion of S-form (7.9% of An. gambiae identified) was in sample from Toumbokro, in the southern Guinea savannah. The G119S mutation was found in both M and S molecular forms with frequency from 30.9 to 35.2%. Conclusion This study revealed a wide distribution of insensitive acetylcholinesterase due to the G119S mutation in both M and S molecular forms of the populations of An. gambiae s.s. tested. The low cross-resistance between carbamates and organophosphates highly suggests involvement of other resistance mechanisms such as metabolic detoxification or F290V mutation.

Background: The city of Abidjan, Côte d'Ivoire has increasingly faced multiple outbreaks of Aedes mosquito-borne arboviral diseases (e.g., dengue (DEN) and yellow fever (YF)) during the recent years, 2017-2023. Thus, we assessed and compared Aedes aegypti larval and adult population dynamics and Stegomyia indices in four urbanized areas with differential arboviral incidences in Abidjan, Côte d'Ivoire., Methods: From August 2019 to July 2020, we sampled Aedes mosquito immatures (larvae and pupae), adults and breeding habitats in Anono and Gbagba with high arboviral incidences and Ayakro and Entente with low arboviral incidences in the Abidjan city, using standardized methods. Sampling was conducted in the peridomestic and domestic (indoors and outdoors) premises during short dry season (SDS), short rainy season (SRS), long dry season (LDS) and long rainy season (LRS). The abdomens and ovaries of Ae. aegypti females were examined to determine their blood-meal and parity statuses. Stegomyia indices (container index: CI, house index: HI and Breteau index: BI), blood-meal status and parity rates were compared by study sites and seasons and with the World Health Organization (WHO)-established epidemic thresholds., Results: Overall, Aedes and arboviral risk indices were high and similar between the four study areas. In total, 86,796 mosquitoes were identified and dominated by Ae. aegypti species (97.14%, 84,317/86,796). The most productive larval breeding habitats were tires, discarded containers and water storage containers. CI, HI, and BI in Anono (22.4%, 33.5% and 89.5), Ayakro (23.1%, 43.8% and 91.0), Entente (15.9%, 24.8% and 48.5) and Gbagba (23.3%, 43.0% and 102.0) were high in the respective study sites. Stegomyia indices were higher than the WHO-established epidemic thresholds during any seasons for DEN, and LRS and SRS for YF. The numbers of Ae. aegypti-positive breeding sites were higher in the domestic premises (68.0%, 900/1,324) than in the peridomestic premises (32.0%, 424/1,324). In the domestic premises, Ae. aegypti-positive breeding sites (94.6%, 851/4,360) and adult individuals (93.4%, 856/916) were mostly found outdoors of houses. Aedes aegypti adult females were mostly unfed (51.3%, 203/396), followed by blood-fed (22.2%, 88/396), gravid (13.9%, 55/396) and half-gravid (12.6%, 50/396), and had parity rate of 49.7% (197/396) that was comparable between the study sites., Conclusions: The city of Abidjan, Côte d'Ivoire is highly infested with Ae. aegypti which showed comparable ecological patterns across study sites and seasons. Thus, the local communities are exposed to high and permanent risks of transmission of DEN and YF viruses that were above the WHO-established epidemic thresholds throughout. The results provide a baseline for future vector studies needed to further characterize the observed patterns of local Ae. aegypti abundances and behaviors, and risks of transmission of these arboviruses. Community-based larval source management of identified productive containers might reduce Ae. aegypti numbers and risks of transmission of Aedes-borne arboviruses in Abidjan, and other sub-Saharan African cities., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Adjobi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The health district of Sakassou is one of the 83 health districts in Côte d'Ivoire, located in a zone with very high malarial transmission rates, with an incidence rate of ≥40% Therefore, to guide vector control methods more effectively, it was crucial to have a good understanding of the vectors in the area. This study aimed to determine the level of malarial transmission during the dry season in Sakassou, Côte d'Ivoire. Female Anopheles mosquitoes were sampled using human landing catches (HLCs) and pyrethrum spraying catches (PSCs). The larvae were collected using the 'dipping' method. A total of 10,875 adult female mosquitoes of Anopheles gambiae were collected. The PCR analysis revealed that all individuals were Anopheles coluzzii . The geographical distribution of potential breeding sites of Anopheles showed the presence of An. coluzzii in all the wetlands of the city of Sakassou. During the dry season, the human-biting rate of An. coluzzii was 139.1 bites/person/night. An exophagic trend was displayed by an adult female of An. coluzzii . The entomological inoculation rate during the dry season was 1.49 infectious bites/person/night. This study demonstrated that An. coluzzii was the main vector of malarial transmission in Sakassou, and the intensity of transmission remains high throughout the dry season., Competing Interests: The authors declare there is no conflict., (© 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).)

The necrotrophic fungus Botritys cinerea takes advantage of the oxidative burst to facilitate tissue infection, leading to substantial losses during tomato postharvest. Tomato fruit is a source of carotenoids, pigments with a wide variety of isomeric configurations that determine their antioxidant capacity. Here, fruit susceptibility to B. cinerea was assessed in Micro-Tom Near Isogenic lines harboring mutations that alter the profile of carotenoids. Wound-inoculated fruit of the mutants Delta carotene (Del) and tangerine (t), which show large variety of carotenoids rather than the major accumulation of trans-lycopene, were less susceptible to the pathogen. Differences in susceptibility between the mutants were only observed in ripe fruit, after the formation of carotenoids, and they were associated with attenuation of damage caused by reactive oxygen species. The greater variety of carotenoid isomers, which in turn contributed to the greater lipophilic antioxidant capacity of fruit, was associated with the less susceptible mutants, Del and t. Together, our data reveals a potential activity of carotenoids in fruit defense, in addition to the well-known and widespread ecological role as attractors of seed dispersers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Background: Entomological surveillance provides critical information on vectors for appropriate malaria vector control and strategic decision-making. The widely documented insecticide resistance of malaria vectors in Côte d'Ivoire requires that any vector control intervention deployment be driven by entomological data to optimize its effectiveness and appropriate resource allocations. To achieve this goal, this study documents the results of monthly vector surveillance and insecticide susceptibility tests conducted in 2019 and a review of all previous entomological monitoring data used to guide vector control decision making. Furthermore, susceptibility to pirimiphos-methyl and clothianidin was assessed in addition to chlorfenapyr and pyrethroids (intensity and piperonyl butoxide (PBO) synergism) tests previously reported. Vector bionomic data were conducted monthly in four sites (Sakassou, Béoumi, Dabakala and Nassian) that were selected based on their reported high malaria incidence. Adult mosquitoes were collected using human landing catches (HLCs), pyrethrum spray catches (PSCs), and human-baited CDC light traps to assess vector density, behaviour, species composition and sporozoite infectivity., Results: Pirimiphos-methyl and clothianidin susceptibility was observed in 8 and 10 sites, respectively, while previous data reported chlorfenapyr (200 µg/bottle) susceptibility in 13 of the sites, high pyrethroid resistance intensity and increased mortality with PBO pre-exposure at all 17 tested sites. Anopheles gambiae sensu lato was the predominant malaria vector collected in all four bionomic sites. Vector density was relatively higher in Sakassou throughout the year with mean biting rates of 278.2 bites per person per night (b/p/n) compared to Béoumi, Dabakala and Nassian (mean of 48.5, 81.4 and 26.6 b/p/n, respectively). The mean entomological inoculation rate (EIR) was 4.44 infective bites per person per night (ib/p/n) in Sakassou, 0.34 ib/p/n in Beoumi, 1.17 ib/p/n in Dabakala and 1.02 ib/p/n in Nassian. The highest EIRs were recorded in October in Béoumi (1.71 ib/p/n) and Nassian (3.22 ib/p/n), in July in Dabakala (4.46 ib/p/n) and in May in Sakassou (15.6 ib/p/n)., Conclusion: Based on all results and data review, the National Malaria Control Programme developed and implemented a stratified insecticide-treated net (ITN) mass distribution in 2021 considering new generation ITNs. These results also supported the selection of clothianidin-based products and an optimal spraying time for the first indoor residual spraying (IRS) campaign in Sakassou and Nassian in 2020., (© 2023. The Author(s).)

Anopheles coluzzii and An. gambiae -the two most recently radiated species of the An. gambiae complex and the major Afrotropical malaria vector species-are identified by markers in the X-centromeric IGS rDNA region. Putative IGS-hybrids are rarely found in the field, except in restricted areas where genomic studies have led to the hypothesis that the observed IGS-patterns are due to cryptic taxa rather than to hybridization between the two species. We investigated the genome-wide levels of admixture in two villages in Côte d'Ivoire where high levels of IGS-hybrids have been detected, confirming unparalleled high frequencies in the coastal village. Genotyping of 24 Ancestry Informative Markers (AIMs) along the three chromosomes produced discordant results between the IGS-marker and the multilocus genotype obtained for AIMs across the whole genome (29%) as well as AIMs on chromosome-X (considered to be fundamental for species reproductive isolation) only (21%). Results highlight a complicated pattern of admixture that deserves deeper genomic analyses to understand better possible underlying causes (from extensive processes of hybridization to the existence of different cryptic taxa), and stress the need of developing advanced diagnostics for An. coluzzii, An. gambiae and putative new taxa, instrumental for assessing taxon-specific epidemiological characters.

Agroecosystems have been associated with risk of malaria. The aim of this study was to determine the relationship between three agroecosystems: (i) rubber plantation (RP); (ii) oil palm plantation (OPP); (iii) no cash crop plantation (NCCP) and the prevalence of Plasmodium falciparum infection among children living in the Aboisso region. In the three villages within (Ehania-V5) or close (N'zikro) or far from (Ayébo) to each agroecosystem (RP, OPP, and NCCP), two cross-sectional parasitological surveys were carried out during the dry and the peak of the long wet seasons. A total of 586 children aged 1-14 years were recruited in the three villages to determine the prevalence of malaria using conventional microscopy. Plasmodium falciparum was the dominant species with an overall infection prevalence of 40.8%. There was a significant difference in prevalence between agroecosystems, during both the dry (p = 0.002) and wet seasons (p < 0.001), which was higher in agricultural settings compared with the NCCP environment, whatever the season. The prevalence of P. falciparum infection increased from the dry to the wet season in agricultural settings (RP and OPP), whereas no difference was noted for NCCP. Less than 18% of children use insecticide-treated nets (ITNs) in the three villages, ranging from 6 (in RP) to 30% (in OPP). Multivariate analysis indicated that age (1-4; 5-9; and 10-14 years) was not associated with malaria risk, but the season and living in agricultural villages were associated with a greater risk of malaria infection. Risk of malaria exposure was fourfold higher in children from agricultural villages than their counterpart from the non-agricultural area. Our findings highlight significant variations in the prevalence of P. falciparum according to agroecosystem and season. The findings will be useful in designing and implementing malaria control interventions by the National Malaria Control Program., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Studies done in Bouaké (Côte d'Ivoire) about 20-yr ago reported that Anopheles gambiae s.l. Giles was the major malaria vector. The present study aimed to update these data and to identify the main vectors. Mosquitoes were collected in Allokokro and Petessou villages between June 2014 and December 2015 using the human landing catching method. Potential breeding sites of An. gambiae s.l. were identified in August and October 2014 and mapped using GPS. Anopheles species were morphologically and molecularly [polymerase chain reaction (PCR)] identified. Ovaries of female were dissected to determine the parity and infection with Plasmodium was detected in head and thorax by quantitative PCR. In Allokokro, the biting rate of An. gambiae s.s was significantly greater than Anopheles coluzzii, whereas, in Petessou, biting rates of both species were comparable. Plasmodium falciparum (Haemosporida: Plasmodiidae), Plasmodium malariae (Haemosporida: Plasmodiidae), and Plasmodium ovale (Haemosporida: Plasmodiidae) identified in both villages. The infection rates of An. gambiae s.s. and An. coluzzii were not significantly different. The entomological inoculation rate (EIR) of An. gambiae s.s. for P. falciparum was 9-fold greater than that of An. coluzzii in Allokokro; however, in Petessou, the EIRs of both species were comparable. In both village, An. gambiae s.s was responsible for P. falciparum and P. ovale transmission whereas An. coluzzii transmitted all three Plasmodium species., (© The Author(s) 2020. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: A severe outbreak of dengue occurred in Burkina Faso in 2016, with the most cases reported in Ouagadougou, that highlights the necessity to implement vector surveillance system. This study aims to estimate the risk of arboviruses transmission and the insecticide susceptibility status of potential vectors in four sites in Burkina Faso. Methods: From June to September 2016, house-to-house cross sectional entomological surveys were performed in four cities stretching along a southwest-to-northeast railway transect. The household surveys analyzed the presence of Aedes spp. larvae in containers holding water and the World Health Organization (WHO) larval abundance indices were estimated. WHO tube assays was used to evaluate the insecticide susceptibility within Aedes populations from these localities. Results: A total of 31,378 mosquitoes' larvae were collected from 1,330 containers holding water. Aedes spp. was the most abundant (95.19%) followed by Culex spp. (4.75%). Aedes aegypti a key vector of arboviruses (ARBOV) in West Africa was the major Aedes species found (98.60%). The relative larval indices, house index, container and Breteau indexes were high, up to 70, 35, and 10, respectively. Aedes aegypti tended to breed mainly in discarded tires and terracotta jars. Except in Banfora the western city, Ae. aegypti populations were resistant to deltamethrin 0.05% in the other localities with low mortality rate under 20% in Ouagadougou whereas they were fully susceptible to malathion 5% whatever the site. Intermediate resistance was observed in the four sites with mortality rates varying between 78 and 94% with bendiocarb 0.1%. Conclusions: This study provided basic information on entomological indices that can help to monitor the risks of ARBOV epidemics in the main cities along the railway in Burkina Faso. In these cities, all larval indices exceeded the risk level of ARBOV outbreak. Aedes aegypti the main species collected was resistant to deltamethrin 0.05% and bendiocarb 0.1% whereas they were fully susceptible to malathion 5%. The monitoring of insecticide resistance is also important to be integrated to the vector surveillance system in Burkina Faso.

Environmental changes related to agricultural practices and activities can impact malaria transmission. In the objective to evaluate this impact on the human-vector contact, the level of human exposure to Anopheles vector bites was assess by an immuno-epidemiological indicator based on the assessment of the human IgG antibody response to the Anopheles gambiae gSG6-P1 salivary peptide, previously validated as a pertinent biomarker. Two cross-sectional surveys were carried out in the dry and rainy season in three villages with intensive agricultural plantations (N'Zikro with rubber cultivation, Ehania-V5 and Ehania-V1 with palm oil exploitation) and in a control village without plantations (Ayébo). Overall, 775 blood samples were collected in filter papers from children aged 1 to 14 years-old for immunological analysis by ELISA. The IgG levels to the gSG6-P1 salivary peptide significantly differed between studied villages both in the dry and the rainy seasons ( P  < 0.0001) and were higher in agricultural villages compared to the control area. In particular, the level of specific IgG in Ehania-V5, located in the heart of palm oil plantations, was higher compared to other agricultural villages. Interestingly, the level of specific IgG levels classically increased between the dry and the rainy season in the control village (P < 0.0001) whereas it remained high in the dry season as observed in the rainy season in agricultural villages. The present study indicated that rubber and oil palm plantations could maintain a high level of human exposure to Anopheles bites during both the dry and rainy seasons. These agricultural activities could therefore represent a permanent factor of malaria transmission risk.

Arbovirus infections, mainly transmitted by Aedes mosquito, are emerging in Africa. Efficient vector control requires an understanding of ecological factors which could impact on the risk of transmission, such as environmental changes linked to agricultural practices. The present study aims to assess the level of human exposure to Aedes mosquito bites in different agroecosystem area, using an immunological tool which quantifies human IgG antibody response to one Ae. aegypti salivary peptide. Specific IgG responses were assessed during dry and rainy seasons, in children living in different villages in Côte d'Ivoire: N'Zikro (rubber and oil palm exploitations), Ehania-V5 (oil palm), and Ayébo (without intensive agricultural activities). In the dry season, specific IgG levels were significantly lower in Ayébo compared to Ehania-V5 and N'Zikro and, interestingly, were similarly high in both villages with cultivations. In the rainy season, no difference of specific IgG was observed between villages. Specific IgG responses remained therefore high during both seasons in villages associated with intensive agricultural. The rubber and oil palm cultivations could maintain a high level of human exposure to Aedes mosquito bites during both dry and rainy seasons. These agricultural activities could represent a permanent risk factor of the transmission of arboviruses.

Background: The effectiveness of malaria control programmes through implementation of vector control activities is challenged by the emergence of insecticide resistance. In the South-Eastern region of Côte d'Ivoire, where palm oil plantations remain the predominant agricultural crop, the susceptibility of wild Anopheles gambiae sensu lato species is still unknown and thus requires a particular attention. The current study was carried out to address the gap by in-depth characterization of susceptibility level of An. gambiae mosquitoes from Ehania-V1 to WHO-recommended doses of six insecticides belonging to available classes and also to screen a subset for target site mutations and possible inhibition of P450 enzymes., Results: Overall results showed variable resistance profile across WHO-recommended insecticides tested. Mortalities ranged from 8.3% (the lowest mortality was recorded with DDT) to 98% (the highest mortality was recorded with fenitrothion). Importantly, mortality to deltamethrin, an important pyrethroid used in public health for impregnation of mosquito nets was close to 98%, precluding a possible susceptibility to this insecticide, albeit further investigations are required. Pre-exposure of An. gambiae s.l. to PBO did not show any significant variation across insecticides (p = 0.002), although a partial increase was detected for alphacypermethrin and bendiocarb, suggesting a low of activity of cytochrome P450 enzymes (p = 0.277). High frequency of kdr L1014F was recorded in both Anopheles coluzzii (91%) and in An. gambiae (96%), associated with ace-1 R G119S mutation at low frequency (<20%)., Conclusion: The high mortality rate to deltamethrin, organophosphate and the non-detection of P450 activity in resistance observed in Ehania-V1 appears as a positive outcome for further control strategies as metabolic-based P450 resistance remains major challenge to manage. These results should help the National Malaria Control Programme when designing strategies for vector control in palm oil areas of Côte d'Ivoire.

Background: Aedes mosquito-transmitted outbreaks of dengue and yellow fever have been reported from rural and urban parts of Côte d'Ivoire. The present study aimed at assessing Aedes spp. oviposition ecology in variously urbanized settings within arbovirus foci in southeastern Côte d'Ivoire., Methods: Aedes spp. eggs were sampled using a standard ovitrap method from January 2013 to April 2014 in different ecosystems of rural, suburban and urban areas. Emerged larvae were reared until the adult stage for species identification., Results: Aedes spp. oviposition ecology significantly varied from rural-to-urban areas and according to the ecozones and the seasons. Species richness of Aedes spp. gradually decreased from rural (eight species) to suburban (three species) and urban (one species) areas. Conversely, emerged adult Aedes spp. mean numbers were higher in the urban (1.97 Aedes/ovitrap/week), followed by the suburban (1.44 Aedes/ovitrap/week) and rural (0.89 Aedes/ovitrap/week) areas. Aedes aegypti was the only species in the urban setting (100 %), and was also the predominant species in suburban (85.5 %) and rural (63.3 %) areas. The highest Ae. aegypti mean number was observed in the urban (1.97 Ae. aegypti/ovitrap/week), followed by the suburban (1.20 Ae. aegypti/ovitrap/week) and rural (0.57 Ae. aegypti/ovitrap/week) areas. Aedes africanus (9.4 %), Ae. dendrophilus (8.0 %), Ae. metallicus (1.3 %) in the rural, and Ae. vittatus (6.5 %) and Ae. metallicus (1.2 %) in the suburban areas each represented more than 1 % of the total Aedes fauna. In all areas, Aedes species richness and abundance were higher in the peridomestic zones and during the rainy season, with stronger variations in species richness in the rural and in abundance in the urban areas. Besides, the highest Culex quinquefasciatus abundance was found in the urban areas, while Eretmapodites chrysogaster was restricted to the rural areas., Conclusions: Urbanization correlates with a substantially higher abundance in Aedes mosquitoes and a regression of the Aedes wild species towards a unique presence of Ae. aegypti in urban areas. Aedes wild species serve as bridge vectors of arboviruses in rural areas, while Ae. aegypti amplifies arbovirus transmission in urban areas. Our results have important ramifications for dengue and yellow fever vector control and surveillance strategies in arbovirus foci in southeastern Côte d'Ivoire.

Background: An experimental hut station built at M'Bé in 1998 was used for many years for the evaluation of insecticidal product for public health until the civil war broke out in 2002. Breeding sites of mosquitoes and selection pressure in the area were maintained by local farming practices and the West African Rice Development Association (WARDA, actually AfricaRice) in a large rice growing area. Ten years after the crisis, bioassays, molecular and biochemical analyses were conducted to update the resistance status and study the evolution of resistance mechanisms of Anopheles gambiae s.s population., Methods: Anopheles gambiae s.s larvae from M'Bé were collected in breeding sites and reared until emergence. Resistance status of this population to conventional insecticides was assessed using WHO bioassay test kits for adult mosquitoes, with 10 insecticides belonging to pyrethroids, pseudo-pyrethroid, organochlorides, carbamates and organophosphates with and without the inhibitor piperonyl butoxyde (PBO). Molecular and biochemical assays were carried out to identify the L1014F kdr, L1014S kdr and ace-1(R) alleles in individual mosquitoes and to detect potential increase in mixed function oxidases (MFO) level, non-specific esterases (NSE) and glutathione S-transferases (GST) activities., Results and Discussion: Anopheles gambiae s.s from M'Bé exerted high resistance levels to organochlorides, pyrethroids, and carbamates. Mortalities ranged from 3% to 21% for organochlorides, from 50% to 75% for pyrethroids, 34% for etofenprox, the pseudo-pyrethroid, and from 7% to 80% for carbamates. Tolerance to organophosphates was observed with mortalities ranging from 95% to 98%. Bioassays run with a pre-exposition of mosquitoes to PBO induced very high levels of mortalities compared to the bioassays without PBO, suggesting that the resistance to pyrethroid and carbamate relied largely on detoxifying enzymes' activities. The L1014F kdr allelic frequency was 0.33 in 2012 compared to 0.05 before the crisis in 2002. Neither the L1014S kdr nor ace-1(R) mutations were detected. An increased activity of NSE and level of MFO was found relative to the reference strain Kisumu. This was the first evidence of metabolic resistance based resistance in An. gambiae s.s from M'Bé., Conclusion: The An. gambiae s.s population showed very high resistance to organochlorides, pyrethroids and carbamates. This resistance level relied largely on two major types of resistance: metabolic and target-site mutation. This multifactorial resistance offers a unique opportunity to evaluate the impact of both mechanisms and their interaction with the vector control tools currently used or in development.