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Featured researches published by Jean-Louis Sarthou.


Lancet Infectious Diseases | 2014

The rise and fall of malaria in a west African rural community, Dielmo, Senegal, from 1990 to 2012: a 22 year longitudinal study

Jean-François Trape; Adama Tall; Cheikh Sokhna; Alioune Badara Ly; Nafissatou Diagne; Ousmane Ndiath; Catherine Mazenot; Vincent Richard; Abdoulaye Badiane; Fambaye Dieye-Ba; Joseph Faye; Gora Ndiaye; Fatoumata Diene Sarr; Clémentine Roucher; Hubert Bassene; Aissatou Toure-Balde; Christian Roussilhon; Ronald Perraut; André Spiegel; Jean-Louis Sarthou; Luiz Hildebrando Pereira da Silva; Odile Mercereau-Puijalon; Pierre Druilhe; Christophe Rogier

BACKGROUND A better understanding of the effect of malaria control interventions on vector and parasite populations, acquired immunity, and burden of the disease is needed to guide strategies to eliminate malaria from highly endemic areas. We monitored and analysed the changes in malaria epidemiology in a village community in Senegal, west Africa, over 22 years. METHODS Between 1990 and 2012, we did a prospective longitudinal study of the inhabitants of Dielmo, Senegal, to identify all episodes of fever and investigate the relation between malaria host, vector, and parasite. Our study included daily medical surveillance with systematic parasite detection in individuals with fever. We measured parasite prevalence four times a year with cross-sectional surveys. We monitored malaria transmission monthly with night collection of mosquitoes. Malaria treatment changed over the years, from quinine (1990-94), to chloroquine (1995-2003), amodiaquine plus sulfadoxine-pyrimethamine (2003-06), and finally artesunate plus amodiaquine (2006-12). Insecticide-treated nets (ITNs) were introduced in 2008. FINDINGS We monitored 776 villagers aged 0-101 years for 2 378 150 person-days of follow-up. Entomological inoculation rate ranged from 142·5 infected bites per person per year in 1990 to 482·6 in 2000, and 7·6 in 2012. Parasite prevalence in children declined from 87% in 1990 to 0·3 % in 2012. In adults, it declined from 58% to 0·3%. We recorded 23 546 fever episodes during the study, including 8243 clinical attacks caused by Plasmodium falciparum, 290 by Plasmodium malariae, and 219 by Plasmodium ovale. Three deaths were directly attributable to malaria, and two to severe adverse events of antimalarial drugs. The incidence of malaria attacks ranged from 1·50 attacks per person-year in 1990 to 2·63 in 2000, and to only 0·046 in 2012. The greatest changes were associated with the replacement of chloroquine and the introduction of ITNs. INTERPRETATION Malaria control policies combining prompt treatment of clinical attacks and deployment of ITNs can nearly eliminate parasite carriage and greatly reduce the burden of malaria in populations exposed to intense perennial malaria transmission. The choice of drugs seems crucial. Rapid decline of clinical immunity allows rapid detection and treatment of novel infections and thus has a key role in sustaining effectiveness of combining artemisinin-based combination therapy and ITNs despite increasing pyrethroid resistance. FUNDING Pasteur Institutes of Dakar and Paris, Institut de Recherche pour le Développement, and French Ministry of Cooperation.


The Journal of Infectious Diseases | 2000

Reduced Immune Activation and T Cell Apoptosis in Human Immunodeficiency Virus Type 2 Compared with Type 1: Correlation of T Cell Apoptosis with β2 Microglobulin Concentration and Disease Evolution

Philippe Michel; Aissatou Toure Balde; Christian Roussilhon; Georgette Aribot; Jean-Louis Sarthou; Marie-Lise Gougeon

This study analyzes the degree of immune activation and characterizes apoptosis in lymphocytes from healthy West African donors or patients infected with human immunodeficiency virus (HIV)-1 or -2. The lower decline of CD4 T cells in HIV-2- compared with HIV-1-infected donors is associated with lower levels of immune activation, evaluated by HLA-DR expression on lymphocytes and sera concentrations of IgG and beta2 microglobulin (beta2m). Ex vivo apoptosis was found in both infections in all lymphocyte subsets, including CD4 and CD8 T cells, as well as B cells, but was lower in HIV-2 than in HIV-1 infection. Interestingly, high correlations were found in HIV-2- and HIV-1-infected donors between the level of CD4 T cell apoptosis and beta2m concentration and progression of the disease. These observations support the hypothesis that long-term activation of the immune system, weaker in HIV-2 infection, significantly contributes to T cell deletion and disease evolution.


Immunology Letters | 1995

Acute Plasmodium falciparum infection is associated with increased percentages of apoptotic cells

Aissatou Toure Balde; Jean-Louis Sarthou; Christian Roussilhon

The impact of acute malaria infection on the level of spontaneous apoptosis, i.e., the percentage of apoptotic cells detectable in lymphocytes cultured without any exogenous stimulus for 3 days in vitro, was evaluated. Quantitation of apoptosis was performed by staining of lymphocyte nuclei with propidium iodide and analysis of the fluorescence by cytometry. The mean apoptosis of 23 HIV-negative patients (15 Africans and 8 Europeans) determined during a confirmed Plasmodium falciparum attack was 27.2% (95% confidence interval (CI) = 23.5-30.7%) i.e., 2.2 times the mean level found in 49 controls (12.4%, CI = 11.1-13.6). These controls included age- and sex-matched Africans (n = 37) and Europeans (n = 12) differing only by their previous level of exposure to P. falciparum. Naive (European) as well as previously exposed (African) subjects showed dramatically elevated levels of spontaneous apoptosis during the malaria attack (mean = 22.5%, CI = 20.7-24.4 for Europeans; mean = 29.7%, CI = 24.6-34.7 for Africans). Such unusually raised levels were observed for at least 1.5 months and were probably detectable for longer periods as suggested by the fact that the mean level of spontaneous apoptosis in healthy Africans was basically higher (13.8%, CI = 12.5-15) than the one found in healthy Europeans (8.2%, CI = 6.3-10.1) (P = 0.0001). Selective immunomagnetic cell isolations carried out immediately before apoptosis quantitation showed that this process affected not only the alpha beta T cells (CD4+ T cells as well as CD8+ T cells) but also the gamma delta T cells and the B-lymphocyte subset.(ABSTRACT TRUNCATED AT 250 WORDS)


Acta Tropica | 1991

A study of the genomic diversity of Plasmodium falciparum in Senegal 2. Typing by the use of the polymerase chain reaction

Odile Mercereau-Puijalon; Thierry Fandeur; Serge Bonnefoy; Catherine Jacquemot; Jean-Louis Sarthou

The genomic polymorphism of Plasmodium falciparum was investigated in a series of samples collected in Senegal during one transmission season. PCR analysis was performed on several genes coding for blood-stage antigens: the gene for the major merozoite surface antigen P190, the gene for the second merozoite surface antigen MSA2 and the gene coding for antigen 96tR/GBP130. In each case, several distinct forms of the genes studied were observed. Both the MAD20 and K1 allelic families of P190 genes were observed. PCR analysis of a single variable region did not differentiate each isolate. However, when the data obtained for several markers are combined, each isolate had a specific genotype. Thus, using PCR to study in parallel several loci is a useful tool to genetically type strains.


Journal of Immunological Methods | 1995

Flow cytometry detection of surface antigens on fresh, unfixed red blood cells infected by Plasmodium falciparum

Hélène Jouin; Y.O. Goguet de la Salmonière; Charlotte Behr; M. Huyin Qan Dat; Jean-Claude Michel; Jean-Louis Sarthou; L. Pereira Da Silva; Philippe Dubois

The immunofluorescence detection of parasite-specific antigens on the surface of red blood cells infected by Plasmodium falciparum parasites is usually performed by visual detection under a fluorescence microscope. We describe here a technique permitting the analysis of surface immunofluorescence labelling by flow cytometry. Infected red blood cells are selected on the basis of their parasitic DNA and RNA content by Hoechst and Thiazole Orange vital dyes. Cytometric analysis of these labels, as well as general erythrocyte characteristics assessed by analysis of forward and side scatter allows the selection of viable intact infected erythrocytes from other blood cells. The integrity of these selected erythrocytes was confirmed by the absence of labelling with antibodies directed against internal components such as spectrin. This technique permits the detection of specific surface immunofluorescence staining on red blood cells infected with mature stages of P. falciparum by antibodies in sera from hyperimmune Saimiri monkeys. Using Thiazole Orange dye for detection of parasitised cells, this analysis was performed on a FACSscan apparatus equipped with a single laser.


Journal of Medical Virology | 1997

Prevalence of antibodies to hepatitis A, C, and E viruses in different ethnic groups in French Guiana

Antoine Talarmin; Mirdad Kazanji; Thierry Cardoso; Jean-François Pouliquen; Joëlle Sankale-Suzanon; Jean-Louis Sarthou

In order to determine the prevalence of antibodies to hepatitis A, C, and E viruses (HAV, HCV, and HEV) in the various ethnic groups and areas of French Guiana, sera (996 for HCV and HEV, 941 for HAV) were tested for antibodies to these viruses using ELISAs.


Scandinavian Journal of Immunology | 1993

T-cell stimulation with purified mycobacterial antigens in patients and healthy subjects infected with Mycobacterium leprae: secreted antigen 85 is another immunodominant antigen

Pascal Launois; M'b N'diaye Niang; Jean-Louis Sarthou; F. Rivier; Annie Drowart; J.P. Van Vooren; Jacques Millan; Kris Huygen

Peripheral blood leucocytes from 9 paucibacillary and 12 multibacillary leprosy patients, from 18 healthy controls and from 34 healthy leprosy contacts were stimulated with three mycobacterial heat shock proteins with respective molecular weights of 70,65 and 18 kDa and with the secreted 30–32 kDa protein, also called antigen 85. Antigen 85 was found to be the most powerful T‐cell antigen (as measured by lymphoproliferation and IFN‐γ secretion), eliciting a positive response in all (100%) paucibacillary patients and in all lepromin‐positive controls and contacts. The three heat shock proteins (hsp) were less active T‐cell stimuli. Reactivity to the 70 kDa hsp was found in only 44% of the paucibacillary patients, in 80% of the lepromin‐positive controls and in 60% of the lepromin‐positive leprosy contacts. The 65 kDa hsp stimulated T cells in 89% of the paucibacillary patients and in 80% of the lepromin‐positive controls and contacts. Responsiveness to the 18 kDa hsp, finally, was clearly more frequent in tuberculoid leprosy patients (78%) than in lepromin‐positive controls (40%) or lepromin‐positive leprosy contacts (4%). T‐cell reactivity of 8 lepromin‐negative controls, of 9 lepromin‐negative contacts and of 12 multibacillary leprosy patients was low to all the antigens tested. Although proliferative and IFN‐γ responses were generally closely related, some subjects demonstrated a dissociation of these two immune parameters. Our data confirm previous findings on the powerful T‐cell stimulatory properties of antigen 85 during M. leprae infection and suggest that this antigen is indeed a potentially protective T‐cell immunogen.


Parasitology Research | 1993

Lymphocyte response in vitro toPlasmodium falciparum merozoite antigens in donors from a holoendemic area

Alioune Dieye; Hans-G. Heidrich; Christophe Rogier; Jean-François Trape; Pascal Launois; Anthony A. Holder; Jean-Louis Sarthou

Crude merozoite antigens from Plasmodium falciparum were used to evaluate the profilerative response of peripheral mononuclear cells (PBMCs) from 114 inhabitants of the village of Dielmo (Senegal, West Africa) exposed continuously to malaria transmission. The high or low responses to merozoite antigens obtained in lymphocyte stimulation assays were correlated with the presence or absence of parasites, IFN-γ production and HLA phenotype. The high responders produced high levels of IFN-γ, in contrast to the low responders, most of whom did not secrete IFN-γ (23/27). Among others, the two HLA phenotypes HLA-B51 and HLA-DR1 were significantly associated with a high response (P<0.05).


Research in Immunology | 1989

Phenolic glycolipid-1 from M. leprae inhibits oxygen free radical production by human mononuclear cells

Pascal Launois; L Blum; Alioune Dieye; J Millan; Jean-Louis Sarthou; M.A. Bach

We studied the effect of PGL1, a phenolic glycolipid unique to Mycobacterium leprae, on the activation of the phagocyte oxidative respiratory burst, by measuring the chemiluminescence (CL) generated by normal mononuclear cells. PGL1 induced a decrease in oxygen free radical production stimulated by mycobacteria (M. leprae, BCG and M. kansasii) or by phorbol myristate acetate, but did not prevent the binding or ingestion of fluorescein-conjugated mycobacteria. In contrast, mycoside A from M. kansasii, a structurally related compound, did not alter the CL response. In addition, treatment of M. leprae with anti-PGL1 antibodies failed to restore the response to this microorganism. PGL1 could act as an oxygen species scavenger and protect M. leprae from killing by toxic oxygen metabolites.


Acta Tropica | 1991

A study of the genomic diversity of Plasmodium falciparum in Senegal 1. Typing by southern blot analysis

Odile Mercereau-Puijalon; Catherine Jacquemot; Jean-Louis Sarthou

The genomic polymorphism of Plasmodium falciparum was investigated in a series of samples collected in Senegal during one transmission season. Restriction site polymorphism was studied by Southern blot analysis using six different probes. The patterns of the ribosomal RNA genes and of the gene coding for antigen 2L indicated a limited genomic polymorphism. Sequences hybridizing to the repeats of the Palo Alto/Wellcome serotype of S-antigen were found in one out of twelve isolates examined. This strain was shown to express the Palo Alto serotype. Restriction fragment length polymorphism was observed for the 332 gene and the 11.1 locus. The hybridization patterns showed that each sample had a distinct 11.1 locus. A comparison of three probes (332, 11.1 and rep20) detecting fragment length polymorphism indicated that maximum sensitivity was obtained using the subtelomeric repeats rep20; less sensitive patterns were observed using the 11.1 27 bp repeat probe. By using these three probes it was found that all samples were genetically distinct.

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Alioune Dieye

Cheikh Anta Diop University

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Annie Drowart

Université libre de Bruxelles

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Jean-François Trape

Institut de recherche pour le développement

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