Palynostratigraphy and palaeoenvironmental characterization and evidence of Oligocene in the terrestrial sedimentary basin, Bingerville area, Southern Côte d'Ivoire, Northern Gulf of Guinea

A palynological investigation of two shallow boreholes in Anna, Bingerville area, at 13 km Northwest Abidjan, Southern Côte d’Ivoire, yielded rich and relatively well-preserved dinoflagellate cyst’s  assemblages that allowed recognition of Oligocene age. This recognition was based on global  dinoflagellate cyst events, including mainly Lejeunecysta species represented by cf. Lejeunecysta  communis, L. lata, L. pulchra, Lejeunecysta sp. cf. L. granosa, cf. L. globosa, L. beninensis and other  Pheolodinium magnificum, P. africanum, Selenopemphix nephroïdes and Cordosphaeridium inodes.  They are associated to terrestrial spores and pollen grains such as Magnastriatites howardii,  Spirosyncolpites spiralis, Perfotricolpites digitatus, Retitricoporites irregularis, Retimonocolpites  irregularis, Pachydermites diederixii, Psilatricolporites operculatus and Punctodiporites harrisii. The  palynostratigraphic interpretations are based on a comparison with calibrated dinoflagellate cyst ranges  from several reference sections, mainly in the peri-atlantic and incidentally peri-pacific basins. This  study showed changes in the relative abundances of different species or groups of morphologically  related species. These changes are palaeoenvironmentally controlled, indicating a deposition occurred between the continental nearshore and marginal marine areas under continental influence. The  prevalence of peridinioid dinocysts assemblage suggests deposition in a subtropical province whereas  terrestrial pollen grains and spores provided by plants of coastal vegetation dominated by pteridophyts and angiosperms evoke mangrove and swamp forests. These new palynological data, notably the  presence of Oligocene especially in the Ivorian terrestrial basin north of the so called “faille des  lagunes”, specifies and modifies the previous local stratigraphic scale.Key words: Palynostratigraphy, palaeoenvironment, Oligocene, sedimentary basin, Côte d’Ivoire

Characteristics of HIV-2 and HIV-1/HIV-2 Dually Seropositive Adults in West Africa Presenting for Care and Antiretroviral Therapy: The IeDEA-West Africa HIV-2 Cohort Study.

HIV-2 is endemic in West Africa. There is a lack of evidence-based guidelines on the diagnosis, management and antiretroviral therapy (ART) for HIV-2 or HIV-1/HIV-2 dual infections. Because of these issues, we designed a West African collaborative cohort for HIV-2 infection within the framework of the International epidemiological Databases to Evaluate AIDS (IeDEA).We collected data on all HIV-2 and HIV-1/HIV-2 dually seropositive patients (both ARV-naive and starting ART) and followed-up in clinical centres in the IeDEA-WA network including a total of 13 clinics in five countries: Benin, Burkina-Faso Côte d'Ivoire, Mali, and Senegal, in the West Africa region.Data was merged for 1,754 patients (56% female), including 1,021 HIV-2 infected patients (551 on ART) and 733 dually seropositive for both HIV-1 and HIV 2 (463 on ART). At ART initiation, the median age of HIV-2 patients was 45.3 years, IQR: (38.3-51.7) and 42.4 years, IQR (37.0-47.3) for dually seropositive patients (p = 0.048). Overall, 16.7% of HIV-2 patients on ART had an advanced clinical stage (WHO IV or CDC-C). The median CD4 count at the ART initiation is 166 cells/mm(3), IQR (83-247) among HIV-2 infected patients and 146 cells/mm(3), IQR (55-249) among dually seropositive patients. Overall, in ART-treated patients, the CD4 count increased 126 cells/mm(3) after 24 months on ART for HIV-2 patients and 169 cells/mm(3) for dually seropositive patients. Of 551 HIV-2 patients on ART, 5.8% died and 10.2% were lost to follow-up during the median time on ART of 2.4 years, IQR (0.7-4.3).This large multi-country study of HIV-2 and HIV-1/HIV-2 dual infection in West Africa suggests that routine clinical care is less than optimal and that management and treatment of HIV-2 could be further informed by ongoing studies and randomized clinical trials in this population