Haemosporidian parasites of Antelopes and other vertebrates from Gabon, Central Africa

Re-examination, using molecular tools, of the diversity of haemosporidian parasites (among which the agents of human malaria are the best known) has generally led to rearrangements of traditional classifications. In this study, we explored the diversity of haemosporidian parasites infecting vertebrate species (particularly mammals, birds and reptiles) living in the forests of Gabon (Central Africa), by analyzing a collection of 492 bushmeat samples. We found that samples from five mammalian species (four duiker and one pangolin species), one bird and one turtle species were infected by haemosporidian parasites. In duikers (from which most of the infected specimens were obtained), we demonstrated the existence of at least two distinct parasite lineages related to Polychromophilus species (i. e., bat haemosporidian parasites) and to sauropsid Plasmodium (from birds and lizards). Molecular screening of sylvatic mosquitoes captured during a longitudinal survey revealed the presence of these haemosporidian parasite lineages also in several Anopheles species, suggesting a potential role in their transmission. Our results show that, differently from what was previously thought, several independent clades of haemosporidian parasites (family Plasmodiidae) infect mammals and are transmitted by anopheline mosquitoes

Increasing Access to Surgical Services in Sub-Saharan Africa: Priorities for National and International Agencies Recommended by the Bellagio Essential Surgery Group

In this Policy Forum, the Bellagio Essential Surgery Group, which was formed to advocate for increased access to surgery in Africa, recommends four priority areas for national and international agencies to target in order to address the surgical burden of disease in sub-Saharan Africa

Targeting the ERAD Pathway via Inhibition of Signal Peptide Peptidase for Antiparasitic Therapeutic Design

Early secretory and endoplasmic reticulum (ER)-localized proteins that are terminally misfolded or misassembled are degraded by a ubiquitin- and proteasome-mediated process known as ER-associated degradation (ERAD). Protozoan pathogens, including the causative agents of malaria, toxoplasmosis, and leishmaniasis, contain a minimal ERAD network relative to higher eukaryotic cells. Herein, we exploit this fact to show that the malaria parasite Plasmodium falciparum is highly sensitized to the inhibition of components of this protein quality control system. Using a variety of approaches, including activity-based protein profiling, mammalian cell- and yeast-based assays, and resistance selection, we show small molecule inhibitors of a protease component of malarial ERAD, PfSPP, simultaneously disrupt the protein’s ability to facilitate degradation of unstable proteins and inhibit its proteolytic function, resulting in lethality for the parasite. Collectively, these data validate ER quality control as a novel vulnerability for the parasite and specifically, confirm the suitability of PfSPP as an antimalarial target

États généraux de la Francophonie scientifique: Actes des " États généraux de la Francophonie scientifique ", Paris (France), 17 février 1995

ISBN : 2-9200-2157-5Confrontée aux bouleversements que subit la planète, aux révolutions technologiques et scientifiques, la Francophonie doit se positionner face à une évolution mondiale pour faire entendre sa voix dans le concert des régions et recrutements politiques, économiques ou culturels. Les États généraux de la Francophonie scientifique ont réuni les spécialistes des sujets définis comme autant de priorités pour l'avenir du français comme langue de communication internationale. Cet ouvrage qui présente l'ensemble des interventions de personnalités politiques, scientifiques et universitaires, propose des solutions concrètes à la définition d'une politique globale en faveur de la promotion de la langue française dans les secteurs d'activité stratégiques : les autoroutes de l'information, l'économie, l'enseignement, l'ingénierie linguistique, les médias, la science

Insecticide susceptibility of <it>Aedes aegypti</it> populations from Senegal and Cape Verde Archipelago

<p>Abstract</p> <p>Background</p> <p>Two concomitant dengue 3 (DEN-3) epidemics occurred in Cape Verde Archipelago and Senegal between September and October 2009. <it>Aedes aegypti</it> was identified as the vector of these epidemics as several DEN-3 virus strains were isolated from this species in both countries. The susceptibility to pyrethroids, organochlorine, organophosphates and carbamate was investigated in two field strains of <it>Aedes aegypti</it> from both countries using WHO diagnostic bioassay kits in order to monitor their the current status of insecticide susceptibility.</p> <p>Findings</p> <p>The two tested strains were highly resistant to DDT. The Cape Verde strain was found to be susceptible to all others tested insecticides except for propoxur 0.1%, which needs further investigation. The Dakar strain was susceptible to fenitrothion 1% and permethrin 0.75%, but displayed reduced susceptibility to deltamethrin, lambda-cyhalothrin and propoxur.</p> <p>Conclusions</p> <p>As base-line results, our observations stress a careful management of insecticide use for the control of <it>Ae. aegypti</it>. Indeed, they indicate that DDT is no longer efficient for the control of <it>Ae</it>. <it>aegypti</it> populations in Cape Verde and Dakar and further suggest a thorough follow-up of propoxur susceptibility status in both sites and that of deltamethrin and lambda-cyhalothrin in <it>Ae. aegypti</it> populations in Dakar. Thus, regular monitoring of susceptibility is greatly needed as well as the knowing if this observed resistance/susceptibility is focal or not and for observed resistance, the use of biochemical methods is needed with detailed comparison of resistance levels over a large geographic area.</p> <p>Keywords</p> <p><it>Aedes aegypti</it>, Insecticides, Susceptibility, Cape Verde, Senegal</p

Efficacy of praziquantel against urinary schistosomiasis and reinfection in Senegalese school children where there is a single well-defined transmission period

Background: Human schistosomiasis is a significant health problem in Sub-Saharan Africa. In Niakhar, West central Senegal, the transmission of S. haematobium occurs seasonally between July and November. No control measures have been implemented despite high prevalence reported in previous studies. This aim of this study was to i) determine the current prevalence of S. haematobium in children at Niakhar, ii) assess the efficacy of one dose of PZQ (40 mg/kg) against S. haematobium and iii) monitor reinfection. Methods: The current study was carried out in a cohort of 329 children aged five to 15 years enrolled from six villages in Niakhar to determine the efficacy of one dose of PZQ, as well as reinfection. Parasitological screening was performed in June 2011 to determine the baseline prevalence of S. haematobium, and then a single dose of PZQ was administered to all selected subjects in the transmission season in August 2011. The efficacy of PZQ treatment and reinfection were monitored respectively five weeks after in September 2011 and from February to March 2012. Results: At baseline, the overall prevalence and the heavy intensity of infection were 73.2 % and 356.1eggs/10 ml of urine. Significant differences in the prevalence and intensity of S. haematobium infection were noted between villages. A single dose of PZQ significantly reduced the prevalence of S. haematobium infection from 73.2 % to 4.6 % and the geometric mean intensity of infection from 356.1 to 43.3 eggs/10 ml of urine. The cure rates ranged from 89.4 % to 100 %. The egg reduction rates also ranged from 77.6 % to 100 %. Two to three months after the period of transmission, the overall rate of reinfection was 12.6 % and was significantly higher in male children than in female children. The overall prevalence at this period was 13.8 %, which was significantly lower than the prevalence at baseline (73.2 %). Conclusion: The Niakhar study area remains a hot spot of urinary schistosomiasis in Senegal with differences in transmission between villages. This study suggests that when transmission is strictly seasonal, Praziquantel shows the expected efficacy in reducing the prevalence and intensity of infection, but also a significant effect on the occurrence of reinfection