Area Of Senegal Research Articles

Malaria prevention knowledge, attitudes, and practices (KAP) among adolescents living in an area of persistent transmission in Senegal: Results from a cross-sectional study.

While malaria morbidity has sharply declined in several areas in Senegal, it remains an important problem in the southern part of the country, particularly among adolescents. Understanding adolescents' knowledge, attitudes, prevention and care-seeking practices is important to inform more targeted interventions aimed at optimizing adolescents' uptake of malaria prevention and control measures. This study assessed malaria-related knowledge, attitudes, and practices (KAP) among adolescents living in a highly persistent transmission area in Senegal. A community-based cross-sectional survey was conducted among 391 adolescents living in the Saraya health district. A multistage random sampling technique was used to select households. An electronic questionnaire developed on Open Data Kit (ODK), was used to collect data on socio-demographic characteristics, household assets, adolescents' knowledge of malaria, as well as their attitudes with regards to malaria prevention, and care-seeking behaviors. Bivariate and multivariate analyses were performed to assess factors associated with adolescents' KAP towards malaria. Nearly, one-third of the participants had good knowledge of malaria (34.4%) and good practice in regards to malaria preventive measures (32.8%) while 59.0% had a positive attitude and 73.8% had good care-seeking behavior regarding malaria. Multivariate analysis revealed that a primary (aOR = 5.43, p = 0.002) or secondary level of education (aOR = 10.41, p = 0.000) was associated with good knowledge of malaria transmission, signs, and prevention measures. Male individuals had lower knowledge compared to female ones (aOR = 0.40, p = 0.001). Individuals belonging to households from the highest wealth quintile were more likely to have a positive attitude towards malaria compared to those from households in the lowest wealth quintile (aOR = 3.49, p = 0.004). The odds of positive attitude towards malaria decreased among participants with koranic and primary education level, respectively (aOR = 0.14, p = 0.005) and (aOR = 0.24, p = 0.019). A positive attitude was 1.89 more likely to be (aOR = 1.89, p = 0.026) associated with good practice of prevention measures compared to adolescents who demonstrated negative attitudes. Individuals from households in the fourth (aOR = 0.42, p = 0.024), middle (aOR = 0.34, P = 0.005), and second (aOR = 0.42, p = 0.027) wealth quintiles were less likely to use malaria prevention measures compared to those from households in the highest wealth quintile. The study revealed that adolescents, generally have poor levels of malaria knowledge and low uptake of malaria prevention and control interventions. Targeted interventions for high-risk adolescents are needed, that focus on improving their knowledge of the disease and effective preventive measures, and on increasing their access to health care services and LLINs.

Analysis of social acceptability in the implementation of a congestion pricing area in Senegal

Urban road pricing is presented as an effective instrument in the context of public transportation policies to improve sustainability in large cities and their surroundings. Among the main problems of its implementation is the lack of social acceptance. The present article, through a population survey, aims to analyze the social acceptability in the implementation of an urban toll in the city of Dakar to identify the effectiveness of this measure on mobility patterns and the advantages and disadvantages declared by citizens as indicators of the degree of social acceptability. The results of the research reveal a set of significant implications in the field of transportation policies that serve as the basis for strategic decision making and to ensure an adequate level of social acceptability of the proposed toll system.

Institut Pasteur Dakar Mobile Lab: Part of the Solution to Tackle COVID Pandemic in Senegal, a Model to Be Exploited

The COVID-19 pandemic required massive testing of potential patients in resource-constrained areas in Senegal. The first case of COVID-19 was reported on 2 March 2020 in Dakar city and on 10 March, the first cases were reported in Touba city, the second most populous city in Senegal. Following the scale of confirmed COVID-19 cases in Touba city, the Institut Pasteur de Dakar mobile laboratory truck (MLT) was deployed on March 13 to bring diagnostics to the point of need for better management of patient and outbreak control. The MLT deployed is a 6 × 6 truck equipped with an isolator for sample inactivation, a generator and batteries to ensure energy autonomy, and a molecular platform for pathogens detection. Nasal and oropharyngeal swabs were collected from suspected COVID-19 cases and sent to the MLT located at the Touba primary healthcare center. Samples were extracted and RNA amplified by real time qRT-PCR. A total of 11,693 samples were collected from 14 regions of Senegal and tested between March to August 2021. Within the samples tested, 10.6% (1240/1693) were positive for SARS-CoV-2. Furthermore, the MLT allowed the confirmation of the first cases of COVID-19 in 25 out of 79 health districts of Senegal. Thereby, the MLT deployment during the first 6 months of COVID-19 in Senegal allowed rapid processing of suspected case samples collected in Touba and other surrounding areas and, thus, significantly contributed to the outbreak response and early case management in Senegal.

Evaluation of the Efficacy of Fludora® Fusion WP-SB 56.25 (Mixture of Clothianidin and Deltamethrin) against Anopheles coluzzii Laboratory and An. arabiensis Wild Colonies.

For malaria control, the application of long-lasting insecticidal nets and indoor residual spraying has led to a significant reduction in morbidity and mortality. However, the sustainability of these gains is hampered by the increase in insecticide resistance. It is therefore judicious to evaluate new insecticide formulations. In comparison to clothianidin and deltamethrin, the efficacy and residual effect of Fludora® Fusion was evaluated using an Anopheles coluzzii laboratory and An. arabiensis wild colonies in huts from August 2016 to June 2017 on cement and mud walls. Mortality was recorded at 24, 48, 72, and 96 h post exposure. Like deltamethrin and clothianidin, Fludora® Fusion showed delayed mortality rates above the WHO’s 80% threshold over a period of 11 months with the laboratory strain. With the wild strain, while residual efficacy was observed at 2 months for the three insecticides, no residual efficacy was observed at 8 months at 24 h in both substrates. However, the increased efficacy was observed with increased holding periods (72 h and 96 h). These findings suggest that Fludora® Fusion could be an alternative candidate since this duration covers the transmission period in most areas in Senegal.

Malaria parasite carriage before and two years after the implementation of seasonal malaria chemoprevention: a case study of the Saraya health district, southern Senegal.

Background : Seasonal malaria chemoprevention (SMC) has been adopted and implemented in the southern regions of Senegal in children aged between three and 120 months since 2013. Scaling up this strategy requires its evaluation to assess the impact. This study was carried out to determine the dynamics of Plasmodium falciparum carriage before and after two years of SMC implementation. Methods : Four household surveys were conducted in villages in the health district of Saraya, which is a SMC implementation area in Senegal. These villages were selected using probability proportional to size sampling. Each selected village was divided into segments containing at least 50 children. In each segment, a household questionnaire was administered to the parents or legal representatives of children aged three to 120 months. Blood smears were collected to determine P. falciparum prevalence by microscopy one month before the first round of SMC, one month after the last round of the first SMC campaign and two years after the start of the implementation. Results : A total of 2008 children were included with a mean average age of 4.81 (+/-2.73) years. Of the study population, 50.33% were more than five years old and 50.3% were male. In 2013, mosquito net ownership was 99.4 % before the SMC campaign and 97.4% after. In 2015, it was 36.6% before and 45.8% after the campaign. In 2013, the prevalence of plasmodium carriage was 11.8% before and 6.1% after the SMC campaign. In 2015, the prevalence was 4.9% before the administration of SMC and this increased up to 15.3% after. Malaria prevalence was high among children over five years old and in boys. Conclusions : The decrease in Plasmodium falciparum parasite prevalence, which subsequently increased after two years of SMC implementation in this study, suggests adding an extra cycle of the SMC or adjusting the administration period.

Dietary Intakes and Nutritional Status of Mother-Child (6-23 Months Old) Pair Targeted through the "Organic Residual Products for Biofortified Foods for Africa Project" in Rural Area in Senegal

Background: Despite micronutrient supplementation and food fortification strategies carried out for decades, micronutrient deficiencies remain prevalent among children under 5 years old in rural area in Senegal. The OR4FOOD project was implemented as a preventive and long-term approach to reduce malnutrition through biofortification.
 Objective: We aimed to assess the baseline dietary intakes and nutritional status of the mother-child (6-23 months old) pair in a rural community in Senegal. 
 Methods: Dietary intakes were assessed using dietary recall questionnaires and weight food records. All foods and beverages consumed from waking to bedtime were quantified, and nutrient intakes were calculated. The nutritional status was measured by anthropometry.
 Results: Results showed that 77.2% of children had low dietary diversity score. Only 18% of them received an appropriate complementary feeding according to the minimum acceptable diet. Cereals and legumes were among the most consumed food groups, whereas orange-fleshed sweet potato (OFSP) and animal food products were rarely consumed. Median dietary intakes of iron, zinc, and vitamin A were lower than the recommended dietary allowances. Acute malnutrition and stunting affected 14.6% and 16.9% of children, respectively. Overall, 20.8% of mothers were underweighted, and overweight/obesity affected 23.1% of them.
 Conclusion: Malnutrition remains prevalent in rural areas of Senegal and affects both mothers and children. Furthermore, their nutrient requirements were not covered by the diet. Millet and cowpea being widely consumed, optimizing their iron and zinc content through biofortification and the introduction of OFSP might improve micronutrient intakes and would be promising strategies to prevent child malnutrition.

Non-crop habitats concurrently drive crop colonization by the millet head miner and regulation by natural enemies

Non-crop habitats, depending on their composition, can enhance the abundance and diversity of natural enemies of crop pests, but also at the same time provide resources to pests, thereby reducing the effect on pest incidence and resulting yield losses. The objective of the present study was to test (1) the effect of semi-natural habitats in the landscape on crop colonization by pests and natural regulation, and (2) the relationship between natural regulation and pest incidence. The pearl millet head miner (MHM) was selected as a case study because it is a key pest of millet cultivated in traditional pesticide-free tree-crop agroforestry systems in which its control mostly relies on the action of natural enemies.A set of 24 millet fields were selected in a 20×20 km area in Senegal, from the analysis of high-resolution satellite images (Pléiades), and hypotheses on the relative abundance of semi-natural habitats (here trees and rangelands) in the agricultural landscape. Millet fields were monitored for pest infestation of panicles and pest natural regulation. We used partial least squares structural equation modelling (PLS-PM) to evaluate the relationships between the abundance and diversity of semi-natural habitats at the landscape scale, crop colonization, natural pest regulation, and pest incidence.Panicle colonization by the MHM was generally high (14–92%) and increased with the abundance of trees and to a lesser extent with the rangeland area at a 1000 m-radius around millet fields. However, regulation provided by natural enemies was amplified by the abundance of trees at a local scale (250 m-radius around millet fields). This was particularly true at early crop colonization of the MHM with parasitism and direct predation on eggs and young larvae. This multi-scale effect of semi-natural habitats on crop colonization and natural regulation could explain why no clear relationship between crop colonization and pest incidence, nor natural regulation and pest incidence, was observed. Future studies on the identification of complex species-specific interactions between trees and natural enemies should provide a better understanding of the ecological processes underlying the performance of natural regulation of MHM populations.

Malaria parasite carriage before and two years after the implementation of seasonal malaria chemoprevention: a case study of the Saraya health district, southern Senegal

Background: Seasonal malaria chemoprevention (SMC) has been adopted and implemented in the southern regions of Senegal in children aged between three and 120 months since 2013. Scaling up this strategy requires its evaluation to assess the impact. This study was carried out to determine the dynamics of Plasmodium falciparum carriage before and after two years of SMC implementation. Methods: Four household surveys were conducted in villages in the health district of Saraya, which is a SMC implementation area in Senegal. These villages were selected using probability proportional to size sampling. Each selected village was divided into segments containing at least 50 children. In each segment, a household questionnaire was administered to the parents or legal representatives of children aged three to 120 months. Blood smears were collected to determine P. falciparum prevalence by microscopy one month before the first round of SMC, one month after the last round of the first SMC campaign and two years after the start of the implementation. Results: A total of 2008 children were included with a mean average age of 4.81 (+/-2.73) years. Of the study population, 50.33% were more than five years old and 50.3% were male. In 2013, mosquito net ownership was 99.4 % before the SMC campaign and 97.4% after. In 2015, it was 36.6% before and 45.8% after the campaign. In 2013, the prevalence of plasmodium carriage was 11.8% before and 6.1% after the SMC campaign. In 2015, the prevalence was 4.9% before the administration of SMC and this increased up to 15.3% after. Malaria prevalence was high among children over five years old and in boys. Conclusions: The decrease in Plasmodium falciparum parasite prevalence, which subsequently increased after two years of SMC implementation in this study, suggests adding an extra cycle of the SMC or adjusting the administration period.

Spatio-temporal Analysis of Surface and Root Zone Soil Moisture Derived from SMAP and SMOS Microwave Satellite Data Using in-situ Measurements in Senegal

Soil moisture plays a regulating role on Earth-Atmosphere flux and the water balance at the terrestrial surface. In recent years, significant progress has been made in quantifying soil moisture from satellite data. Particularly, microwave space remote sensing remains an efficient tool for estimating soil moisture at a large scale. However, the validation by in situ measurements is still needed in some areas such as the Sahel, especially for elaborated products such as soil moisture in the root zone. The present study is contributing to the validation of soil moisture products in the silvopastoral and agricultural system within the Sahelian area in Senegal. Soil moisture products derived from Soil Moisture Active and Passive (SMAP) sensors at 9 and 36 km and Soil Moisture Ocean Salinity (SMOS) at the resolution of 0.25° x 0.25° are compared with in-situ measurements acquired at different depths (from 0 to 100 cm) three validation sites. First, a validation of the in-situ measurements was done to visualize the performance of these sensors in situ for soil moisture recovery on the three study sites (Loumbi, Bawdi, and Niakhar). Second, an estimation of the SMAP, SMOS products of the surface area (5 cm depth) was made. Third, an estimation showed that these microwave sensors follow the soil moisture dynamics whatever the surface and climatic conditions and also despite RMSE higher or equal to the specifications, 0.04 m3/m3. Finally, the results from the soil moisture analysis of the root zone of the satellite and in-situ products are very important.

An agent-based model to simulate the boosted Sterile Insect Technique for fruit fly management

The sterile insect technique (SIT) is a method of biological control of pests and disease vector insects. It includes mass-rearing and release of sterile males of the target species so that wild females mated with sterile males would not produce offspring. An innovative version of this technique, called boosted SIT, relies on the use of sterile males as vectors of biocides to trigger an epizootic in the wild fruit fly population. We built an agent-based model to assess the feasibility of this technique and main modalities of field implementation for the control of the Oriental fruit fly, Bactrocera dorsalis, using the entomopathogenic fungi, Metarizhium anisopliae, as a biocide. The model, called BOOSTIT (BactrOcera dOrsaliS boosTed sIT), simulates the spatio-temporal population dynamics of fruit flies in three different realistic landscape contexts. The releases of infected and uninfected sterile males were simulated and allowed the transmission of the pathogen within the wild fly population as a result of interactions between individuals. A main output was the measurement of losses in mango production. Validation of the model was done by comparing the simulated population dynamics with data from field monitoring (pheromone traps) in three landscapes of the Niayes area in Senegal. The population dynamics of wild flies were then simulated in an intensive cropping and mono-mango cultivar landscape under three scenarios: (1) without the release of sterile males, (2) with the release of non-contaminated sterile males (SIT) and (3) with the release of sterile contaminated males (boosted SIT). The results showed that SIT and boosted SIT strongly reduced the density of wild flies and the amount of infested fruits. Although parameters of the pathogen transfer between individuals need to be studied more deeply, results encourage the implementation of field trials to validate the efficacy of boosted SIT to control fruit flies.

Detection of Potential Zoonotic Bartonella Species in African Giant Rats (Cricetomys gambianus) and Fleas from an Urban Area in Senegal.

Bartonellae are bacteria associated with mammals and their ectoparasites. Rodents often host different species of Bartonella. The aim of this study was to investigate the presence of Bartonella spp. in African giant pouched rats (Cricetomys gambianus) and their ectoparasites in Dakar, Senegal. In 2012, 20 rats were caught, and their fleas were identified. DNA was extracted from 170 selected fleas and qPCR was carried out to detect Bartonella spp. Subsequently, a Bartonella culture was performed from the rat blood samples and the isolated strains (16S rRNA, rpoB, ftsZ and ITS3) were genotyped. A total of 1117 fleas were collected from 19 rats and identified as Xenopsylla cheopis, the tropical rat flea. Bartonella DNA was detected in 148 of 170 selected fleas (87.1%). In addition, Bartonella strains were isolated from the blood of 17 rats (85%). According to Bartonella gene-sequence-based criteria for species definition, the isolated strains were identified as B. massiliensis (four strains) and two potential new species related to the zoonotic B. elizabethae. In this paper, these potentially new species are provisionally called Candidatus Bartonella militaris (11 strains) and Candidatus Bartonella affinis (two strains) until their description has been completed. Cricetomys gambianus and its fleas could constitute a public health risk in Dakar due to the high prevalence of Bartonella infection reported.

Cultivated and wild pearl millet display contrasting patterns of abundance and co-occurrence in their root mycobiome

Fungal communities associated with roots play a key role in nutrient uptake and in mitigating the abiotic and biotic stress of their host. In this study, we characterized the roots mycobiome of wild and cultivated pearl millet [Pennisetum glaucum (L.) R. Br., synonym: Cenchrus americanus (L.) Morrone] in three agro-ecological areas of Senegal following a rainfall gradient. We hypothesized that wild pearl millet could serve as a reservoir of endophytes for cultivated pearl millet. We therefore analyzed the soil factors influencing fungal community structure and whether cultivated and wild millet shared the same fungal communities. The fungal communities associated with pearl millet were significantly structured according to sites and plant type (wild vs cultivated). Besides, soil pH and phosphorus were the main factors influencing the fungal community structure. We observed a higher fungal diversity in cultivated compared to wild pearl millet. Interestingly, we detected higher relative abundance of putative pathotrophs, especially plant pathogen, in cultivated than in wild millet in semi-arid and semi-humid zones, and higher relative abundance of saprotrophs in wild millet in arid and semi-humid zones. A network analysis based on taxa co-occurrence patterns in the core mycobiome revealed that cultivated millet and wild relatives had dissimilar groups of hub taxa. The identification of the core mycobiome and hub taxa of cultivated and wild pearl millet could be an important step in developing microbiome engineering approaches for more sustainable management practices in pearl millet agroecosystems.

Neonatal Mortality in Rural Area in Senegal

Most newborn deaths occur in two regions of the world, South Asia and sub-Saharan Africa. In Senegal, much progress has been made over the past two decades with a reduction in overall infant mortality by 38%. However, the decline in neonatal mortality has been slower during the same period. The objective of this study is to assess neonatal mortality, to determine the different causes and to make recommendations for improving care in rural areas. This is a retrospective study with a descriptive and analytical aim carried out in the pediatrics department of the Diourbel regional hospital, 130 km from Dakar, the Senegalese capital, over a 12-month period from January 1 to January 31, December 2018. All newborns hospitalized in the pediatric ward during the study period were included. Overall mortality was 30.6%, newborns between 0 and 7 days accounted for 90.6% of deaths, INBORNs accounted for 62.3% of deaths. Newborns whose mother’s age was between 20 and 35 years of age accounted for 69.3% of deaths. Newborns of first-time mothers accounted for 40.2% of deaths and those of multiparous mothers 31%. Newborns who did not reach term accounted for 58.9% of deaths. Newborns admitted for respiratory distress represented the majority of deaths 45.5% (n = 93) followed by those with low birth weight 32.5 (n = 65) followed by those with neurological manifestations 30.5 (n = 62). Conclusion: Neonatal mortality is very high in the Diourbel region and the main cause is the lack of human resources and a very insufficient technical platform. The fight against this mortality involves improving the technical platform and recruiting sufficient and well-trained staff.

Analysing the impact of electrification on rural attractiveness in Senegal with mobile phone data.

Reliable and affordable access to electricity has become one of the basic needs for humans and is, as such, at the top of the development agenda. It contributes to socio-economic development by transforming the whole spectrum of people’s lives—food, education, healthcare. It spurs new economic opportunities, thus improving livelihoods. Using a comprehensive dataset of pseudonymized mobile phone records, we analyse the impact of electrification on attractiveness for rural areas in Senegal. We extract communication and mobility flows from call detail records and show that electrification is positively and specifically correlated with centrality measures within the communication network and with the volume of incoming visitors. This increased influence is however circumscribed to a limited spatial extent, creating a complex competition with nearby areas. Nevertheless, we found that the volume of visitors between any two sites could be well predicted from the level of electrification at the destination and the living standard at the origin. In view of these results, we discuss how to obtain the best outcomes from a rural electrification planning strategy. We determine that electrifying clusters of rural sites is a better solution than centralizing electricity supplies to maximize the development of specifically targeted sites.

A large mammal survey in Koyli Alpha Community Wildlife Reserve and its surroundings in the Great Green Wall extension area in Senegal

Wildlife in the Great Green Wall (GGW) area, northern Senegal, is threatened by the cumulative effects of anthropogenic activities, drought, and climatic changes. To support conservation planning in line with the GGW management objectives, we studied large mammal diversity in the Koyli Alpha Community Wildlife Reserve in the GGW extension area. We interviewed local communities, made reconnaissance & transect walks, placed camera traps, and carried out fixed point surveys to map the distribution of mammals & to estimate their relative abundance. The surveys were conducted between May 2017 and December 2019. We identified the presence of nine mammal species belonging to six families: one lagomorph, Cape Hare Lepus capensis; seven carnivores, Common Jackal Canis aureus, Pale/Sand Fox Vulpes pallida, Wild Cat Felis silvestris, Marsh Mongoose Atilax paludinosus, Honey Badger Mellivora capensis, Zorilla Ictonyx striatus, Common Genet Genetta genetta, and one primate, Patas Monkey Erythrocebus patas. Our results indicate that the most of the observed species range broadly across the Koyli Alpha Reserve. The Wild Cat and the Sand Fox were also found outside the reserve around the village of Koyli Alpha. Camera trapping events of humans and domestic animals were high throughout the survey area, and the majority of the large mammals observed were mainly nocturnal. The diversity of large wild mammals identified during this study points to the urgent need for the implementation of a management plan of the biodiversity in this area of the Ferlo.

Key informant perspectives on the challenges and opportunities for using routine health data for decision-making in Senegal

BackgroundIncreasing the performance of routine health information systems (RHIS) is an important policy priority both globally and in Senegal. As RHIS data become increasingly important in driving decision-making in Senegal, it is imperative to understand the factors that determine their use.MethodsSemi-structured interviews were conducted with 18 high- and mid-level key informants active in the malaria, tuberculosis and HIV programmatic areas in Senegal. Key informants were employed in the relevant divisions of the Senegal Ministry of Health or nongovernmental / civil society organizations. We asked respondents questions related to the flow, quality and use of RHIS data in their organizations. A framework approach was used to analyze the qualitative data.ResultsAlthough the respondents worked at the strategic levels of their respective organizations, they consistently indicated that data quality and data use issues began at the operational level of the health system before the data made its way to the central level. We classify the main identified barriers and facilitators to the use of routine data into six categories and attempt to describe their interrelated nature. We find that data quality is a central and direct determinant of RHIS data use. We report that a number of upstream factors in the Senegal context interact to influence the quality of routine data produced. We identify the sociopolitical, financial and system design determinants of RHIS data collection, dissemination and use. We also discuss the organizational and infrastructural factors that influence the use of RHIS data.ConclusionsWe recommend specific prescriptive actions with potential to improve RHIS performance in Senegal, the quality of the data produced and their use. These actions include addressing sociopolitical factors that often interrupt RHIS functioning in Senegal, supporting and motivating staff that maintain RHIS data systems as well as ensuring RHIS data completeness and representativeness. We argue for improved coordination between the various stakeholders in order to streamline RHIS data processes and improve transparency. Finally, we recommend the promotion of a sustained culture of data quality assessment and use.

Multidrug-Resistant Klebsiella pneumoniae Clones from Wild Chimpanzees and Termites in Senegal.

Antibiotic resistance genes exist naturally in various environments far from human usage. Here, we investigated multidrug-resistant Klebsiella pneumoniae, a common pathogen of chimpanzees and humans. We screened antibiotic-resistant K. pneumoniae from 48 chimpanzee stools and 38 termite mounds (n = 415 samples) collected in protected areas in Senegal. The microsatellite method was used to identify chimpanzee individuals (n = 13). Whole-genome sequencing was performed on K. pneumoniae complex isolates to identify antibiotic-resistant genes and characterize clones. We found a high prevalence of carbapenem-resistant K. pneumoniae among chimpanzee isolates (18/48 samples from 7/13 individuals) and ceftriaxone resistance among both chimpanzee individuals (19/48) and termite mounds (7/415 termites and 3/38 termite mounds). The blaOXA-48 and the blaKPC-2 genes were carried by international pOXA-48 and pKPC-2 plasmids, respectively. The ESBL plasmid carried blaCTX-M-15, blaTEM-1B, and blaOXA-1 genes. Genome sequencing of 56 isolates identified two major clones associated with hospital-acquired infections of K. pneumoniae (ST307 and ST147) in chimpanzees and termites, suggesting circulation of strains between the two species, as chimpanzees feed on termites. The source and selection pressure of these clones in this environment need to be explored.

Recruitment of native parasitoids of the tomato leaf miner Tuta absoluta (Meyrick 1917), (Lepidoptera: Gelechiidae) in Senegal

The tomato leaf miner Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is an invasive pest that produces significant damage to tomato crops in Senegal. Biological control is one of the options for its control and a large number of natural enemies have been reported in association with the pest. A five-year field survey was conducted in the main tomato-producing area in Senegal (Niayes) to evaluate the parasitoid complex of T. absoluta in tomato crops. Seven parasitoid species were obtained including Apanteles litae, Chelonus sp., Cotesia vestalis and Meteorus laphygmarum belonging to Braconidae family; Diadegma insulare, Pristomerus pallidus (Ichneumonidae) and Elasmus sp. (Eulophidae). The parasitoid Chelonus sp. was largely the most dominant (60.67%). Larval parasitism was very low (1.05%) but greater during the last years of the study (2016 to 2019). Results showed that parasitism was not affected by time of season. However, diversity of parasitoids was variable across year (p < 0.001). This study is a first step toward development of research and extension programs for conservation of natural enemies of T. absoluta in Senegal.

Mapping Mangrove Zonation Changes in Senegal with Landsat Imagery Using an OBIA Approach Combined with Linear Spectral Unmixing

The mangrove areas in Senegal have fluctuated considerably over the last few decades, and it is therefore important to monitor the evolution of forest cover in order to orient and optimise forestry policies. This study presents a method for mapping plant formations to monitor and study changes in zonation within the mangroves of Senegal. Using Landsat ETM+ and Landsat 8 OLI images merged to a 15-m resolution with a pansharpening method, a processing chain that combines an OBIA approach and linear spectral unmixing was developed to detect changes in mangrove zonation through a diachronic analysis. The accuracy of the discriminations was evaluated with kappa indices, which were 0.8 for the Saloum delta and 0.83 for the Casamance estuary. Over the last 20 years, the mangroves of Senegal have increased in surface area. However, the dynamics of zonation differ between the two main mangrove hydrosystems of Senegal. In Casamance, a colonisation process is underway. In the Saloum, Rhizophora mangle is undergoing a process of densification in mangroves and appears to reproduce well in both regions. Furthermore, this study confirms, on a regional scale, observations in the literature noting the lack of Avicennia germinans reproduction on a local scale. In the long term, these regeneration gaps may prevent the mangrove from colonising the upper tidal zones in the Saloum. Therefore, it would be appropriate to redirect conservation policies towards reforestation efforts in the Saloum rather than in Casamance and to focus these actions on the perpetuation of Avicennia germinans rather than Rhizophora mangle, which has no difficulty in reproducing. From this perspective, it is necessary to gain a more in-depth understanding of the specific factors that promote the success of Avicennia germinans seeding.

Understanding Bactrocera dorsalis trapping to calibrate area‐wide management

AbstractKnowing the dispersal of released insects and estimating the size of field populations are keys to the successful implementation of area‐wide management (AWM) programmes based on the sterile insect technique (SIT), as they determine the release strategy of sterile males. Mark–release–recapture (MRR) is a common method used to estimate field populations and spatiotemporal dynamics. However, the extent to which the pest is attracted to lures is often difficult to identify, thereby biasing extrapolation to movement patterns and population size. We performed MRR experiments on the Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), in a fruit‐growing area in Senegal. Methyl eugenol and protein baits were used to trap males and females, respectively. After studying the suitability of marking B. dorsalis with fluorescent pigments at the laboratory, two releases of marked sterile flies were organized in the centre of an organic mango orchard, first in the late mango fruiting stage and second in the fruit setting stage. Traps were placed symmetrically along a 250 and 500 m radius from the release point. A very small fraction of the released individuals was recaptured: 0.45% in the first release and 3.08% in the second. Trapping of both sterile and wild flies was completely anisotropic. Sterile flies were mostly trapped at a relatively short distance (250 m) from the release point, in the first two days. Male trapping using methyl eugenol was highly effective, whereas the response of females to food bait traps was low. The direction of the wind was the main driver of recapture, with flies heading upwind. The results underline the importance of taking the odour plume around the traps into account when estimating populations, and the heterogeneous spread of the wild population in the landscape for the set‐up of the release strategy of sterile insects for SIT‐based AWM.