Phylogenetic relationships and molecular delimitation of Culicoides Latreille (Diptera: Ceratopogonidae) species in the Afrotropical region: interest for the subgenus Avaritia

Phylogenetic relationships of Culicoides species of the Afrotropical region are problematic as different authors disagree on the placement of species into specific subgenera or groups. In this study we sequenced two mitochondrial (COI and 16S rDNA) and two nuclear (CAD and 28S rDNA) gene fragments to reconstruct phylogenetic relationships within the Avaritia, Remmia and Synhelea subgenera and the Milnei, Neavei and Similis groups of Culicoides using both Bayesian inference and maximum-likelihood approaches. Based on phylogenetic trees, we used the bGMYC (Bayesian General Mixed Yule Coalescent model) and the PTP (Bayesian Poisson Tree Processes) to investigate species boundaries. All species relationships within the studied subgenera and groups were well-supported by using morphological characters and molecular analyses. The subgenus Avaritia includes (i) all of the species of the Imicola group, as well as the putative new species, C. sp. #22, and we confirmed the monophyly of this group; (ii) the Dasyops group includes C. kanagai and C. sp. #54 Meiswinkel (new species), shown to be monophyletic; (iii) the C. sp. #20 belongs to the Orientalis group; (iv) C. grahamii, C. gulbenkiani and C. kibatiensis. Our results also show that subgenus Remmia is monophyletic. Relationships of species of the Milnei group were well-supported and demonstrate the monophyly of this group. Borkent's classification for Similis group is confirmed. In addition, C. neavei and C. ovalis (Neavei group) are placed in the subgenus Synhelea. (Résumé d'auteur

Tuberculose intestinale révélée par une occlusion intestinale aigüe au cours d’une réaction paradoxale au traitement anti-tuberculeux chez un patient immunocompétent: à propos d’un cas et revue de la littérature

La tuberculose intestinale représente 3 à 5% de toutes les localisations viscérales. Malgré l'efficacité démontrée des anti-tuberculeux, des cas d'exacerbation du tableau clinique initial ont été décrits à l'initiation du traitement. Ces réactions dites «paradoxales» sont cependant rarement rapportées chez les immunocompétents et beaucoup moins sous forme d'occlusion intestinale. Nous rapportons un cas de tuberculose intestinale révélée par une occlusion intestinale aigüe au cours d'une réaction paradoxale aux anti-tuberculeux. Il s'agit d'un patient de 26 ans, immunocompétent qui a présenté un syndrome occlusif à un mois de traitement d'une tuberculose pleuro-pulmonaire. La tomodensitométrie (TDM) abdominale était en faveur d'une occlusion intestinale grêlique. La laparotomie objectivait une masse intra-péritonéale avec de multiples adhérences. L'examen anatomopathologique de la pièce opératoire était en faveur d'une tuberculose intestinale. L'évolution était favorable après la poursuite du traitement anti-tuberculeux initial

Colonization of the Mediterranean Basin by the vector biting midge species Culicoides imicola: an old story

Understanding the demographic history and genetic make-up of colonizing species is critical for inferring population sources and colonization routes. This is of main interest for designing accurate control measures in areas newly colonized by vector species of economically important pathogens. The biting midge Culicoides imicola is a major vector of Orbiviruses to livestock. Historically, the distribution of this species was limited to the Afrotropical region. Entomological surveys first revealed the presence of C. imicola in the south of the Mediterranean basin by the 1970's. Following recurrent reports of massive bluetongue outbreaks since the 1990s, the presence of the species was confirmed in northern areas. In this study, we addressed the chronology and processes of C. imicola colonization in the Mediterranean basin. We characterized the genetic structure of its populations across Mediterranean and African regions using both mitochondrial and nuclear markers, and combined phylogeographical analyses with population genetics and approximate Bayesian computation. We found a west/east genetic differentiation between populations, occurring both within Africa and within the Mediterranean basin. We demonstrated that three of these groups had experienced demographic expansions in the Pleistocene, probably because of climate changes during this period. Finally, we showed that C. imicola could have colonized the Mediterranean basin in the late Pleistocene or early Holocene through a single event of introduction; however we cannot exclude the hypothesis involving two routes of colonization. Thus, the recent bluetongue outbreaks are not linked to C. imicola colonization event, but rather to biological changes in the vector or the virus

Senegal: Presidential elections 2019 - The shining example of democratic transition immersed in muddy power-politics

Whereas Senegal has long been sold as a showcase of democracy in Africa, including peaceful political alternance, things apparently changed fundamentally with the Senegalese presidentials of 2019 that brought new configurations. One of the major issues was political transhumance that has been elevated to the rank of religion in defiance of morality. It threatened political stability and peace. In response, social networks of predominantly young activists, created in 2011 in the aftermath of the Arab Spring focused on grass-roots advocacy with the electorate on good governance and democracy. They proposed a break with a political system that they consider as neo-colonialist. Moreover, Senegal’s justice is frequently accused to be biased, and the servility of the Constitutional Council which is in the first place an electoral court has often been denounced

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Epidemiologic and clinicopathologic aspects of Leprosy in Dakar; evaluation of 73 new cases

Hundreds of new leprosy cases are still diagnosed in Dakar despite all the efforts in the struggle by the national program for elimination of leprosy by the Institute of Applied Leprosy in Dakar. The aim of our study was to evaluate the epidemiological, clinicopathological and outcome of new cases of leprosy. A prospective study was conducted over a period of one year listing all new cases of leprosy based on clinical diagnosis, bacteriology and histology. 73 new cases were recorded. The sex ratio was 1.5 and the mean age of 39.5 years. Children aged from 0 to 15 years old represented 12%. The clinical forms were rated in order of decreasing frequency Borderline 47.94%, 30.13% lepromatous lepromatous, indeterminate 8.21, borderline lepromatous 6.84, TT: 5.47%, 1.36 and neurological bb%. Neurological signs were enlarged nerve in 50 cases, a neurological deficit in 16 cases and a sensitive deficit in 16 cases. The complications were burns and ulcerations in 10 cases, a claw in 7 cases, a reversal reaction in 7 cases, erythema nodosum in 4 cases and neuritis in 8 cases. The number of new cases mutilated was 24.65%. The smear was positive in 42% and histology contribution in 91.37% of cases. Our study highlights the significant number of patients with multibacillary contagious, affected children, the high proportion of disability grade 2/OMS reflecting the delay in diagnosis. This delay is due to ignorance, to traditional treatments and low socio-economic status and lack of trained diagnostic teams in different areas apart from referral centres