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Tuberculosis, an airborne disease, is the deadliest human infectious disease caused by one single agent. The African region is among the most affected and most burdensome area in terms of tuberculosis cases. In this paper, we modeled the number of new cases of tuberculosis for 2000–2021 by integer time series. For each African country, we fitted twenty different models and selected the model that best fitted the data. The twenty models were mostly based on the number of new cases following either the Poisson or negative binomial distribution with the rate parameter allowed to vary linearly or quadratically with respect to year. The best fitted models were used to give predictions for 2022–2031. [ABSTRACT FROM AUTHOR]

Will African farmers watch and learn from videos featuring farmers in Bangladesh? Learning videos on rice seed management were made with rural women in Bangladesh. By using a new approach, called zooming-in, zooming-out, the videos were of regional relevance and locally appropriate. When the Africa Rice Center (AfricaRice) introduced them to Africa in 2005, many scientists and civil servants thought that the videos would be culturally inappropriate and hence irrelevant to African smallholder farmers. However, African farmers who watched the videos did not experience cultural barriers. In fact, they enjoyed seeing another part of the world where farmers faced similar problems as theirs, and were able to solve these problems by themselves. To promote wider uptake of the videos a key challenge was to overcome the institutional barriers. Public sector agencies especially had to be convinced that African smallholders appreciated Asian videos. By watching the videos with farmers and listening to their feedback, the skeptical scientists and service providers changed their minds. By 2009, the Bangladeshi rice seed videos had been translated into 20 African languages and so became national products. Videos made according to the zooming-in zooming-out approach can bring farmer-to-farmer extension to a higher level of social aggregation. (Contains 1 table and 1 figure.)

Many plant species adapted to semi-arid environments are grown in the Sahelian region in northern Africa. One such species is Acacia seyal (Delile), a multipurpose leguminous tree grown in various agroecological zones, including saline soils. These challenging arid and semi-arid environments harbor a diversity of arbuscular mycorrhizal fungi (AMF) communities that can develop symbiotic associations with plants to improve their hydromineral nutrition. This study compared the effects of native AMF communities isolated from semi-arid sites (high, moderate, and low salinity zones Ndiafate, Ngane, and Bambey, respectively) and the AMF Rhizoglomus aggregatum on the development and phosphate nutrition of A. seyal seedlings subject to three salinity treatments (0, 340, and 680 mM). Plant height, dry matter weight of the shoots and roots, and phosphorus uptake from the soil were measured. Plants inoculated with AMF native species from each site that were provided with up to 340 mM of NaCl had greater shoot height than plants grown under 680 mM salinity. At NaCl concentrations above 340 mM, shoot and root development of A. seyal seedlings diminished. However, dry matter production of shoots (7%) and roots (15%) improved following AMF inoculation compared with the control (respectively 0.020 and 0.07 g for shoots and roots). When inoculated with AMF isolates from the high salinity zone (Ndiafate), phosphate content/nutrition was increased by 10% around 30 days after inoculation compared with non-inoculated seedlings (2.84 mg/kg of substrate). These results demonstrate that native AMF inoculants are capable of helping plants withstand environmental constraints, especially those exposing plants to harsh climatic conditions. We discuss insights on how AMF influences the interplay between soil phosphorus and perceived salinity that may have implications for broader relationships between plants and symbiotic fungi. [ABSTRACT FROM AUTHOR]

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Enterovirus A71 (EV-A71) is a non-polio enterovirus that currently represents a major public health concern worldwide. In Africa, only sporadic cases have been reported. Acute flaccid paralysis and environmental surveillance programs have been widely used as strategies for documenting the circulation of polio and non-polio enteroviruses. To date, little is known about the molecular epidemiology of enterovirus A71 in Africa where resources and diagnostic capacities are limited. To fill this gap in Senegal, a total of 521 non-polio enterovirus isolates collected from both acute flaccid paralysis (AFP) and environmental surveillance (ES) programs between 2013 and 2020 were screened for enterovirus A71 using real-time RT-PCR. Positive isolates were sequenced, and genomic data were analyzed using phylogeny. An overall rate of 1.72% (9/521) of the analyzed isolates tested positive for enterovirus A71. All positive isolates originated from the acute flaccid paralysis cases, and 44.4% (4/9) of them were isolated in 2016. The nine newly characterized sequences obtained in our study included eight complete polyprotein sequences and one partial sequence of the VP1 gene, all belonging to the C genogroup. Seven out of the eight complete polyprotein sequences belonged to the C2 subgenotype, while one of them grouped with previous sequences from the C1 subgenotype. The partial VP1 sequence belonged to the C1 subgenotype. Our data provide not only new insights into the recent molecular epidemiology of enterovirus A71 in Senegal but also point to the crucial need to set up specific surveillance programs targeting non-polio enteroviruses at country or regional levels in Africa for rapid identification emerging or re-emerging enteroviruses and better characterization of public health concerns causing acute flaccid paralysis in children such as enterovirus A71. To estimate the real distribution of EV-A71 in Africa, more sero-epidemiological studies should be promoted, particularly in countries where the virus has already been reported. [ABSTRACT FROM AUTHOR]

Background. Advanced stages of plantar acral lentiginous melanoma are common in Africa. Inguinal lymph node dissection (ILND) in these cases plays a critical role in disease-free and overall survival. Our study aims to share our experience in ILND for advanced plantar melanomas. Methods and Study Design. Four-year prospective study. Patients. We included all documented cases of advanced stage plantar melanoma with clinically detectable inguinal lymph node metastasis. Twenty-two of 27 patients identified—with mean age 56 years—underwent ILND. Studied Variables. Tumor patterns and stage, surgery, morbidity, oncologic pathology, and evolution were studied. Statistical software assessed the overall survival (OS). Results. Plantar lesions were all excised with a cancer-free margin (3 cm). ILND was performed for 22 patients with visible (n = 11), palpable (n = 7), and ulcerous (n = 4) lymphadenopathies. It was performed through an S-shaped (n = 11) or ellipse-shaped skin incision (n = 11). The tumors were AJCC stage III (n = 18) and IV (n = 2). We found high Breslow index tumor thickness (>3 mm) and an advanced Clark IV stage (n = 20). All operative wounds healed within 46 days (21–90). Wound healing was delayed by suture failure (n = 16), lymphorrhoea (n = 22), and infection (n = 18). After 29 months, three patients had complete remissions, seven had recurrences, and twelve patients had died. The overall survival (OS) at one year was 56%. In two patients with AJCC stage III disease, the OS was better (22 months). Conclusion. In low-income countries, ILND in advanced stages of plantar foot melanoma is a valuable surgical treatment option. Alongside ILND adjuvants, treatment must be available and accessible to improve survival. [ABSTRACT FROM AUTHOR]

Building on previous multicountry surveillance studies of typhoid and others salmonelloses such as the Diseases of the Most Impoverished program and the Typhoid Surveillance in Africa Project, several ongoing blood culture surveillance studies are generating important data about incidence, severity, transmission, and clinical features of invasive Salmonella infections in sub-Saharan Africa and South Asia. These studies are also characterizing drug resistance patterns in their respective study sites. Each study answers a different set of research questions and employs slightly different methodologies, and the geographies under surveillance differ in size, population density, physician practices, access to healthcare facilities, and access to microbiologically safe water and improved sanitation. These differences in part reflect the heterogeneity of the epidemiology of invasive salmonellosis globally, and thus enable generation of data that are useful to policymakers in decision-making for the introduction of typhoid conjugate vaccines (TCVs). Moreover, each study is evaluating the large-scale deployment of TCVs, and may ultimately be used to assess post-introduction vaccine impact. The data generated by these studies will also be used to refine global disease burden estimates. It is important to ensure that lessons learned from these studies not only inform vaccination policy, but also are incorporated into sustainable, low-cost, integrated vaccine-preventable disease surveillance systems. [ABSTRACT FROM AUTHOR]

Farmers in Niger are vulnerable to high millet yield losses due to the millet head miner, Heliocheilus albipunctella De Joannis (Lepidoptera: Noctuidae), for which pest control options are limited. Researchers have developed a procedure to multiply and spread an augmentative biological control agent Habrobracon hebetor Say (Hymenoptera: Braconidae) which is effective in limiting millet yield losses due to the pest. This study assesses the economic viability of small businesses to produce and sell biological control agents. It analyzes the profitability of the businesses under alternative pricing regimes given estimated costs to produce and distribute biological control agents. The economic assessment provides budget analysis for potential businesses and discusses options for scaling, price setting, and organizing. Our study suggests that the small H. hebetor industry should turn a profit in Niger at relatively low prices for the biological control agents of $3.00-$4.00 per bag with 15 bags needed per village. Competitive wages are achievable for the businesses that sell to at least 13 villages. Each business would hire three workers from late May to late August. Commercialization of H. hebetor would generate opportunities for wide geographic distribution of the technology on a sustainable basis in Niger. [ABSTRACT FROM AUTHOR]

• A single T. remus female was able to parasitize about 100 S. frugiperda eggs. • The optimal parasitism was obtained releasing one T. remus female on 70 S. frugiperda. • In a choice scenario, T. remus females did not parasitize any 3-day old eggs. • T. remus sex-ratio is generally in favor of females. • T. remus can be mass reared on the eggs of S. littoralis. The egg parasitoid Telenomus remus has emerged as one of the potential candidates for use in biological control of the of the fall armyworm, Spodoptera frugiperda in Africa. However, its uses in biological control require a better understanding of its biology and the development of a cost-effective mass production. We firstly determined how T. remus reacts to an increasing S. frugiperda egg density. Subsequently we identified its preference for parasitism as a function of S. frugiperda egg age. Finally, we assessed the acceptability of Spodoptera littoralis as a factitious host for T. remus rearing. The number of eggs parasitized by T. remus increased as the egg density increased. Competition between T. remus females resulted in a male-biased sex ratio. Regarding host-eggs age, T. remus females prefer 1-day-old eggs over 2- or 3-day-old eggs. With respect to host acceptability, T. remus was shown to parasitize S. littoralis eggs and produce viable offspring. Although, T. remus tended to parasitize fewer S. littoralis than S. frugiperda eggs it can be used as a factitious host for the mass multiplication of T. remus in a biological control program. [ABSTRACT FROM AUTHOR]

Introduction: The objectives of this study were to investigate the association between HIV infection and dental caries among children in West Africa, and to identify factors associated with dental caries among HIV-infected children.Methods: We conducted a multi-center cross-sectional study in Mali, Senegal and Côte d'Ivoire with a random sample of HIV-infected children aged 5-15 years on antiretroviral therapy and their uninfected siblings. A standardized examination was performed by calibrated dentists. The association between the number of decayed, missing or filled permanent and primary teeth surfaces (DMFdefS) and HIV status was investigated by fitting multivariable zero-inflated negative binomial models, for each age group (<12 and ≥12 years). Factors associated with dental caries could be investigated only for HIV-infected children <12 years old.Results: The sample included 420 HIV-infected children and 418 non-infected siblings. The median DMFdefS was 7 for the HIV-infected children and 2 for the uninfected siblings. The proportion of children with DMFdefS ≥1 was significantly higher among the HIV-infected children than uninfected children (86.0 percent versus 64.4 percent, P < 0.001). The HIV-infected children were less likely to be caries-free than the uninfected siblings in both age groups. We found a higher degree of caries experience among HIV-infected children < 12 years old, in whom it was associated with sweet drink consumption, history of night bottle use, immunosuppression, and younger age at study entry.Conclusions: Although preventable, the burden of dental disease was high in children from families affected by HIV in West Africa and was associated with HIV infection and immunosuppression. [ABSTRACT FROM AUTHOR]

Background: Tanzania, like other African countries, faces significant health workforce shortages. With advisory and partnership from Columbia University, the Ifakara Health Institute and the Tanzanian Training Centre for International Health (TTCIH) developed and implemented the Connect Project as a randomized cluster experimental trial of the childhood survival impact of recruiting, training, and deploying of a new cadre of paid community health workers (CHW), named "Wawazesha wa afya ya Jamii" (WAJA). This paper presents an estimation of the cost of training and deploying WAJA in three rural districts of Tanzania.Methods: Costing data were collected by tracking project activity expenditure records and conducting in-depth interviews of TTCIH staff who have led the training and deployment of WAJA, as well as their counterparts at Public Clinical Training Centres who have responsibility for scaling up the WAJA training program. The trial is registered with the International Standard Randomized Controlled Trial Register number ( ISRCTN96819844 ).Results: The Connect training cost was US$ 2,489.3 per WAJA, of which 40.1 % was for meals, 20.2 % for accommodation 10.2 % for tuition fees and the remaining 29.5 % for other costs including instruction and training facilities and field allowance. A comparable training program estimated unit cost for scaling-up this training via regional/district clinical training centres would be US$ 833.5 per WAJA. Of this unit cost, 50.3 % would involve the cost of meals, 27.4 % training fees, 13.7 % for field allowances, 9 % for accommodation and medical insurance. The annual running cost of WAJA in a village will cost US$ 1.16 per capita.Conclusion: Costs estimated by this study are likely to be sustainable on a large scale, particularly if existing regional/district institutions are utilized for this program. [ABSTRACT FROM AUTHOR]

The legume pod borer, Maruca vitrata (Lepidoptera: Crambidae), is an insect pest species of crops grown by subsistence farmers in tropical regions of Africa. We present the de novo assembly of 3729 contigs from 454- and Sanger-derived sequencing reads for midgut, salivary, and whole adult tissues of this non-model species. Functional annotation predicted that 1320 M. vitrata protein coding genes are present, of which 631 have orthologs within the Bombyx mori gene model. A homology-based analysis assigned M. vitrata genes into a group of paralogs, but these were subsequently partitioned into putative orthologs following phylogenetic analyses. Following sequence quality filtering, a total of 1542 putative single nucleotide polymorphisms (SNPs) were predicted within M. vitrata contig assemblies. Seventy one of 1078 designed molecular genetic markers were used to screen M. vitrata samples from five collection sites in West Africa. Population substructure may be present with significant implications in the insect resistance management recommendations pertaining to the release of biological control agents or transgenic cowpea that express Bacillus thuringiensis crystal toxins. Mutation data derived from transcriptome sequencing is an expeditious and economical source for genetic markers that allow evaluation of ecological differentiation. [ABSTRACT FROM AUTHOR]

Abstract: The Kedougou Kenieba Inlier (KKI) (Paleoproterozoic of Eastern Senegal) is a portion of the West African Craton (WAC) containing a granite-greenstone terrain that experienced three distinct periods of magmatic activity, peaking at 2200, 2160–2130 and 2100–2070Ma. In the Inlier, Paleoproterozoic granitoids and large-scale transcurrent shear zones are spatially associated, suggesting a genetic link between magma bodies and shear zones. Granitic intrusions are associated with all the volcanic episodes and phases of deformation, and have been used to constrain the age of many of these events. Our structural data and deformation sequence indicate that the Mako Greenstone Belt and the adjacent granitoid complexes have undergone a multi-phase evolutionary history that is spread over a prolonged period. The available geochronological data and field studies allowed classification of the granitoids of the KKI into four generations GI, GII, GIII and GIV. The current data suggest that the oldest rocks in the KKI, the Badon granites (2198±2Ma) and the tonalitic gneisses from Tonkouto (2200–2198Ma) (GI), could be correlated with an early Birimian magmatic event. The gneisses, crystallized at depth, record the earliest deformation and in contrast to other tonalites, do not appear to have intruded volcanic rocks. The second manifestation of magmatism was intrusion of mafic diorite – the Gabbro Sandikounda Layered Igneous Complex type (GII) and development of the Laminia Kaourou Plutonic Complex (LKPC) (2160–2130Ma). These bodies pre-date or are sometimes synchronous with a major deformational episode, and may, therefore, have formed very early in convergent Birimian orogenesis. The third major peak of magmatic activity occurred after the above major episode with the development of the oval shaped Diombalou and Bouroumbourou plutons (GIII). The orientation of these plutons parallel to the regional strike of the schistosity indicates structural control on granite emplacement. Eburnean magmatism was terminated in the Mako Belt following compressional Eburnean deformation, with the emplacement of the Tinkoto, Mamakono plutons (GIV) in the east of the complex and continued in the Dialé–Daléma supergroup with the syntectonic emplacement of the Saraya batholith. Garnitiferous granites of crustal derivation were emplaced in the final period of extensional activity around 2080Ma. Field observations suggest the early plutons of the complex granitic (Kakadian) batholith intruded during convergent deformation whereas later igneous activity accompanied regional orogen-parallel extension, followed by exhumation. In the Mako Belt, thickening of the crust was proposed to have caused heating and the ‘apparent diapiric rise’ of the Diombalou and Bouroumbourou plutons. [Copyright &y& Elsevier]

The control of pertussis remains a worldwide concern. Little has been documented about its epidemiology in Africa. The authors have studied pertussis in a prospective cohort of children in a rural West African community over a 13-year period comprising time before and after introduction of a vaccination program. Children under age 15 years who were residents of the Niakhar study area in Senegal were followed prospectively between January 1984 and December 1996 for the occurrence of pertussis. Morbidity and mortality rates were extremely high before the launch of immunization. Crude incidence was 183 per 1,000 child-years at risk under age 5 years, with a 2.8% case-fatality rate. After the introduction of the vaccination program, overall incidence dropped rapidly and dramatically—by 27% after 3 years and 46% after 6 years. The decline in incidence involved all age groups but was most substantial in the group under age 5 years and was particularly pronounced in unvaccinated infants. The median age of acquisition of the disease rose steadily with population vaccine coverage. This study shows the tremendous magnitude of the disease burden in children and the rapid decline after vaccination, and it suggests a strong herd-immunity effect. [ABSTRACT FROM PUBLISHER]

Antibodies to human immunodeficiency virus (HIV) of the IgA, IgG, and IgM isotypes and high levels of the HIV suppressive b-chemokine RANTES (regulated on activation, normally T cell expressed and secreted) were found in the cervicovaginal secretions (CVSs) of 7.5% of 342 multiply and repeatedly exposed African HIV-seronegative female sex workers. The anti-bodies are part of a local compartmentalized secretory immune response to HIV, since they are present in vaginal fluids that are free of contaminating semen. Cervicovaginal antibodies showed a reproducible pattern of reactivity restricted to gp160 and p24. Locally produced anti-env antibodies exhibit reactivity toward the neutralizing ELDKWA epitope of gp41. Study results show that antibodies purified from CVSs block the transcytosis of cell-associated HIV through a tight epithelial monolayer in vitro. These findings suggest that genital resistance to HIV may involve HIV-specific cervicovaginal antibody responses in a minority of highly exposed HIV-seronegative women in association with other protecting factors, such as local production of HIV-suppressive chemokines. [ABSTRACT FROM AUTHOR]

Simple Summary: Mosquito-borne diseases such as malaria, arbovirosis and lymphatic filariasis are major public health issues, particularly in Africa. In order to predict the risk of transmission of these diseases and plan optimal mosquito control interventions, it is vital to have updated information of the mosquito species present, as each of them has a different capacity to transmit different pathogens, and to monitor how these species vary over time, also in relation to environmental and climatic changes. This is achieved by entomological monitoring carried out by various types of traps, whose collection efficacy may vary depending on the mosquito species and the ecological and climatic situation. We carried out collections in two villages in Senegal and showed evidence of a decline of malaria vector species and an increase of lymphatic filarial vectors. Moreover, we showed that using different traps to collect female mosquitoes may provide different estimates of mosquito species composition over time, depending on geographical setting and season. This is very relevant for a correct planning of mosquito monitoring and for appropriate interpretation of the results. Mosquitoes-borne diseases are major public health issues particularly in Africa. Vector control interventions and human-made environmental/climatic changes significantly affect the distribution and abundance of vector species. We carried out an entomological survey targeting host-seeking mosquitos in two different ecological contexts—coastal and inland—in Senegal, by CDC-light and BG-sentinel traps. Results show high predominance of Culex quinquefasciatus (90%) and of Anopheles arabiensis within malaria vectors (46%), with mean numbers of females/trap/nights =8 and <1, respectively, reinforcing previous evidence of changes in species composition and abundance, highlighting thus increasing risk of transmission of filariasis and emerging arboviruses in the Senegambia region. From the methodological perspective, results show a higher specificity of BG traps for Cx. quinquefasciatus and of CDC traps for An. gambiae s.l. and highlight that, despite both traps target the host-seeking fraction of the population, they provide different patterns of species abundance, temporal dynamics and host-seeking activity, leading to possible misinterpretation of the species bionomics. This draws attention to the need of taking into account trapping performance, in order to provide realistic quantification of the number of mosquitoes per units of space and time, the crucial parameter for evaluating vector–human contact, and estimating risk of pathogen transmission. [ABSTRACT FROM AUTHOR]

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an insect native to the tropical and subtropical Americas that has recently spread to Africa, where it predominately attacks maize, sorghum and other plant species. Biological control is an environmentally friendly way of combatting the pest and contributes to an integrated pest management approach. In Africa, several trichogrammatid parasitoids and Telenomus remus Nixon (Hymenoptera: Platygastridae) have been found parasitizing eggs of the FAW. In Niger, the egg parasitoids encountered include Trichogrammatoidea sp. (Hymenoptera: Trichogrammatidae) and Telenomus remus Nixon. Parasitism of the FAW eggs by the two egg parasitoids was assessed in the laboratory, followed by field testing on sentinel eggs. In the laboratory, T. remus parasitized on average 78% of FAW eggs, compared to 25% for Trichogrammatoidea sp. Telenomus remus was able to parasitize egg masses that were fully covered with scales, while Trichogrammatoidea sp. parasitized only uncovered egg masses. On-farm releases of T. remus in sorghum fields caused up to 64% of FAW egg parasitism. Parasitized eggs yielded viable progeny, which can contribute to FAW egg parasitism build-up during the cropping season. Our findings lay the groundwork for the use of T. remus in augmentative releases against FAW in Africa. [ABSTRACT FROM AUTHOR]

The fall armyworm, Spodoptera frugiperda, a moth originating from tropical and subtropical America, has recently become a serious pest of cereals in sub-Saharan Africa. Biological control offers an economically and environmentally safer alternative to synthetic insecticides that are being used for the management of this pest. Consequently, various biological control options are being considered, including the introduction of Telenomus remus, the main egg parasitoid of S. frugiperda in the Americas, where it is already used in augmentative biological control programmes. During surveys in South, West, and East Africa, parasitized egg masses of S. frugiperda were collected, and the emerged parasitoids were identified through morphological observations and molecular analyses as T. remus. The presence of T. remus in Africa in at least five countries provides a great opportunity to develop augmentative biological control methods and register the parasitoid against S. frugiperda. Surveys should be carried out throughout Africa to assess the present distribution of T. remus on the continent, and the parasitoid could be re-distributed in the regions where it is absent, following national and international regulations. Classical biological control should focus on the importation of larval parasitoids from the Americas. [ABSTRACT FROM AUTHOR]

Objective In 2000, a referral hospital in the Gambia accepted a donation of oxygen concentrators to help maintain oxygen supplies. The concentrators broke down and were put into storage. A case study was done to find the reasons for the problem and to draw lessons to help improve both oxygen supplies and the success of future equipment donations. Methods A technical assessment of the concentrators was carried out by a biomedical engineer with relevant expertise. Semi-structured interviews were undertaken with key informants, and content analysis and inductive approaches were applied to construct the history of the episode and the reasons for the failure. Findings Interviews confirmed the importance of technical problems with the equipment. They also revealed that the donation process was flawed, and that the hospital did not have the expertise to assess or maintain the equipment. Technical assessment showed that all units had the wrong voltage and frequency, leading to overheating and breakdown. Subsequently a hospital donations committee was established to oversee the donations process. On-site biomedical engineering expertise was arranged with a nongovernmental organization (NGO) partner. Conclusion Appropriate donations of medical equipment, including oxygen concentrators, can be of benefit to hospitals in resource-poor settings, but recipients and donors need to actively manage donations to ensure that the donations are beneficial. Success requires planning, technical expertise and local participation. Partners with relevant skills and resources may also be needed. In 2002, WHO produced guidelines for medical equipment donations, which address problems that might be encountered. These guidelines should be publicized and used. [ABSTRACT FROM AUTHOR]

Abstract: Field, petrographical and geochemical studies of the Palaeoproterozoic granitoids of the Kédougou inlier (Eastern Sénégal) allow to define four compositional types: (i) the Layered Plutonic Complex consisting of sodic calc-alkaline granitoids defining a trend from Opx-, Cpx- and amphibole-bearing layered gabbros to amphibole-bearing tonalite; the latter shows similarities with adakite-like rocks; (ii) amphibole-bearing granitoids with TTG features occurring as composite batholiths and as isolated oval-shaped plutons cross cutting the entire Birimian metavolcanic and metasedimentary formations; (iii) potassic granitoids defining a trend from Opx-, Cpx-bearing gabbros to amphibole-bearing monzodiorite and preferentially emplaced within the calc-alkaline metavolcanites; (iv) peraluminous biotite-bearing granitoids emplaced within the metasediments of the upper part of the Birimian lithostratigraphical pile. The granitoid suites were emplaced within a time interval of about 80Ma from about 2160Ma (emplacement of the LPC) to 2080Ma (emplacement of the youngest plutons such as the amphibole-bearing TTG granitoid or the pyroxene- and K-feldspar-bearing granitoids). The granitoid suites were emplaced in an immature arc environment [Dia, A., Van Schmus, W.R., Kröner, A., 1997. Isotopic constraints on the age and formation of a Palaeoproterozoic volcanic arc complex in the Kedougou inlier, eastern Senegal, West Africa. J. Afr. Earth Sci. 24 (3), 197–213]. Parental magmas were probably derived from the partial melting of a mantle wedge above a subduction zone. Tonalite magmas of distinctive composition were probably produced by partial melting of the subducting slab itself. They could characterize the early stage of the slab-melting, precursor of the TTG magmatism. The close association of calc-alkaline, trondhjemitic and peraluminous granitoids and the successive emplacement of granitoid groups more and more enriched in K2O recognized in the Kédougou inlier is typical of the Paleoproterozoic granitoid series from West Africa. [Copyright &y& Elsevier]