Biomedical subjects

Pierre-Blaise Matsiegui

Publications and source records attributed to Pierre-Blaise Matsiegui.

14 recordsLinked to original sources

PubMed2006

Short course of quinine plus a single dose of sulfadoxine/pyrimethamine for Plasmodium falciparum malaria.

BACKGROUND: Quinine remains the treatment of choice in hospitalized malaria cases; however, adverse reactions and the long treatment duration of 7 days often hamper its adequate use. Shortening the treatment by adding sulfadoxine/pyrimethamine may enhance compliance and reduce side effects. We aimed to assess the efficacy of a 3-day course of quinine plus a single dose of sulfadoxine/pyrimethamine for the treatment of non-severe hospitalized malaria cases in Lambaréné, Gabon. METHODS: Fifty children aged between 2 and 7 years received quinine dihydrochloride (12 mg/kg every 12 hours for 72 hours), and then a single dose of oral SP (500 mg/25 mg tablet) was given according to weight category. The children were hospitalized for the duration of the treatment and until two consecutive blood smears were negative for malaria parasites. The follow-up period lasted 28 days. RESULTS: Parasites were cleared after 66 hours (SD: 15 hours) and the fever after 46 hours (SD: 24 hours). All patients evaluable by day 28 were negative for malaria parasites (100% efficacy rate, 95% CI: 0.92-1). Only two patients out of 49 had gametocytemia on days 7 and 14. There was no adverse event probably or possibly attributable to the study drugs. CONCLUSIONS: A very high efficacy can be reached using a 3-day course of quinine plus a single dose of sulfadoxine/pyrimethamine for the treatment of non-severe hospitalized malaria cases in our study area.

Animals↗

PubMed2006

Fosmidomycin plus clindamycin for treatment of pediatric patients aged 1 to 14 years with Plasmodium falciparum malaria.

Fosmidomycin plus clindamycin was shown to be efficacious in the treatment of uncomplicated Plasmodium falciparum malaria in a small cohort of pediatric patients aged 7 to 14 years, but more data, including data on younger children with less antiparasitic immunity, are needed to determine the potential value of this new antimalarial combination. We conducted a single-arm study to improve the precision of efficacy estimates for an oral 3-day fixed-ratio combination of fosmidomycin and clindamycin at 30 and 10 mg/kg of body weight, respectively, every 12 hours for the treatment of uncomplicated P. falciparum malaria in 51 pediatric outpatients aged 1 to 14 years. Fosmidomycin plus clindamycin was generally well tolerated, but relatively high rates of treatment-associated neutropenia (8/51 [16%]) and falls of hemoglobin concentrations of > or =2 g/dl (7/51 [14%]) are of concern. Asexual parasites and fever were cleared within median periods of 42 h and 38 h, respectively. All patients who could be evaluated were parasitologically and clinically cured by day 14 (49/49; 95% confidence interval [CI], 93 to 100%). The per-protocol, PCR-adjusted day 28 cure rate was 89% (42/47; 95% CI, 77 to 96%). Efficacy appeared to be significantly reduced in children aged 1 to 2 years, with a day 28 cure rate of only 62% for this small subgroup (5/8). The inadequate efficacy in children of <3 years highlights the need for continued systematic studies of the current dosing regimen, which should include randomized trial designs.

Administration, Oral↗

PubMed2005

Short-course regimens of artesunate-fosmidomycin in treatment of uncomplicated Plasmodium falciparum malaria.

Fosmidomycin is effective against malaria, but it needs to be given for > or =4 days when used alone. We conducted a study of 50 children with Plasmodium falciparum malaria to evaluate the safety and efficacy of consecutively shortened regimens of artesunate-fosmidomycin (1 to 2 mg/kg of body weight and 30 mg/kg of body weight, respectively; doses given every 12 hours). All dosing regimens were well tolerated. Artesunate-fosmidomycin acted rapidly, resulting in consolidated geometric mean parasite and fever clearance times of 24 h and 15 h, respectively. Treatment regimens of > or =2 days led to cure ratios of 100% by day 14 (39/39; 95% confidence interval [95% CI], 91% to 100%). Most importantly, the 3-day regimen achieved 100% cure on day 28 (10/10; 95% CI, 69% to 100%). Treatment with artesunate-fosmidomycin was associated with transient grade I or II neutropenia (absolute neutrophil counts of 750 to 1,200/microl and 400 to 749/microl, respectively) in six or two patients, respectively. Artesunate-fosmidomycin demonstrates the feasibility and potential value of short-course artemisinin-based combination chemotherapy with rapidly eliminated combination partners.

Antimalarials↗

PubMed2005

Short report: Piloting paperless data entry for clinical research in Africa.

Direct data entry, using handheld computers, may simplify and streamline data management, especially in remote settings. We compared the accuracy of data entry using the current standard practice (a paper-based case report form with double data entry) with that using a personal digital assistant (PDA) in a clinical study in rural Gabon. The rate of discrepant entries was 1.7%. Categorical data (presented in "pull down" menus on the PDA) were more commonly discrepant than were continuous "typed in" data (2.4% versus 1.2%; P = 0.001). Both systems functioned smoothly and no data were lost. The clinicians involved in this study preferred the handheld computers, and their use will be considered in future studies in an African clinical research network.

Africa↗

PubMed2005

Assessment of a simplified method for counting leukocytic malaria pigment.

Severe and fatal malaria is associated with the increased presence of malaria hemozoin in peripheral phagocytes. Large studies of this relationship are hampered by the fact that identifying and counting phagocytes on thick blood smears is time consuming. Distinguishing which mononuclear cells are monocytes and which granulocytes are neutrophils requires time and careful training. In this study, we evaluated a simplified method in which only the proportions of hemozoin-containing mononuclear cells and granulocytes are counted. Thick blood films from 471 Gabonese children with malaria were evaluated. We found a linear relationship and a strong correlation between the proportions of hemozoin-containing monocytes versus mononuclear cells (r = 0.85) and neutrophils versus polymorphonuclear cells (r = 0.93), respectively. The two methods had similar predictive values, as estimated by receiver operating characteristics curves. This simplified method can be used to estimate the amount of extra-erythrocytic pigment in peripheral blood, and we suggest that it may be particularly suitable for very large studies.

Animals↗

PubMed2004

Fosmidomycin-clindamycin for the treatment of Plasmodium falciparum malaria.

It has been demonstrated that fosmidomycin has good tolerability and rapid onset of action, but late recrudescences preclude its use alone; in vitro, clindamycin has been shown to act synergistically with fosmidomycin against Plasmodium falciparum. We conducted a study in pediatric outpatients with P. falciparum malaria in Gabon to evaluate the efficacy and safety of an oral combination of fosmidomycin-clindamycin of 30 mg/kg and 10 mg/kg of body weight, respectively, every 12 h. Patients 7-14 years old were recruited in cohorts of 10. The first 10 patients were treated for 5 days. The duration of treatment was then incrementally shortened in intervals of 1 day if >85% of the patients in a cohort were cured by day 14. All dosing regimens were well tolerated, and no serious adverse events occurred. Asexual parasites and fever rapidly cleared in all patients. Cure ratios of 100% on day 14 were achieved with treatment durations of 5 (10/10 patients), 4 (10/10 patients), 3 (10/10 patients), and 2 days (10/10 patients); 1 day of treatment led to a cure ratio of 50% (5/10 patients). Fosmidomycin-clindamycin is safe and well tolerated, and short-course regimens achieved high efficacy in children with P. falciparum malaria. Fosmidomycin-clindamycin is a promising novel treatment option for malaria.

Administration, Oral↗

PubMed2004

Fosmidomycin-clindamycin for Plasmodium falciparum Infections in African children.

BACKGROUND: Fosmidomycin is a new antimalarial drug with a novel mechanism of action. Studies in Africa that have evaluated fosmidomycin as monotherapeutic agent demonstrated its excellent tolerance, but 3-times-daily treatment regimens of >or=4 days were required to achieve radical cure, prompting further research to identify and validate a suitable combination partner to enhance its efficacy. METHODS: We conducted a randomized, controlled, open-label study to evaluate the efficacy and safety of fosmidomycin combined with clindamycin (n=12; 30 and 5 mg/kg body weight every 12 h for 5 days, respectively), compared with fosmidomycin alone (n=12; 30 mg/kg body weight every 12 h for 5 days) and clindamycin alone (n=12; 5 mg/kg body weight every 12 h for 5 days) for the clearance of asymptomatic Plasmodium falciparum infections in schoolchildren in Gabon aged 7-14 years. RESULTS: Asexual parasites were rapidly cleared in children treated with fosmidomycin-clindamycin (median time, 18 h) and fosmidomycin alone (25 h) but slowly in children treated with clindamycin alone (71 h; P=.004). However, only treatment with fosmidomycin-clindamycin or clindamycin alone led to the radical elimination of asexual parasites as measured by day 14 and 28 cure rates of 100%. Asexual parasites reappeared by day 28 in 7 children who received fosmidomycin (day 14 cure rate, 92% [11/12; day 28 cure rate, 42% [5/12]). All regimens were well tolerated, and no serious adverse events occurred. CONCLUSION: The combination of fosmidomycin and clindamycin is well tolerated and superior to either agent on its own with respect to the rapid and radical clearance of P. falciparum infections in African children.

Antimalarials↗

PubMed2003

Atovaquone and proguanil versus amodiaquine for the treatment of Plasmodium falciparum malaria in African infants and young children.

Malaria-related morbidity and mortality are greatest among young children in areas with high malaria transmission intensity. An open-label, randomized study was done to evaluate the efficacy and safety of the combination of atovaquone and proguanil formulated as pediatric-strength tablets (20 and 8 mg/kg of body weight, respectively, administered once daily for 3 days), compared with amodiaquine (10 mg/kg of body weight, once daily for 3 days), among children weighing > or =5 and <11 kg in Gabon. Two hundred patients aged 3-43 months were recruited. Use of atovaquone/proguanil resulted in a cure rate on day 28 of 95% (87 of 92 children), compared with 53% (41 of 78 children) for amodiaquine (difference, 42%; 95% CI, 30%-54%; P<.001). The incidence of adverse events was similar in both groups, and no serious adverse events were attributed to the use of atovaquone/proguanil. Atovaquone/proguanil was found to be highly effective and safe for the treatment of Plasmodium falciparum malaria in infants and young children weighing 5-10 kg in Africa.

Amodiaquine↗

PubMed2003

Prevalence of Plasmodium falciparum infection in pregnant women in Gabon.

BACKGROUND: In areas where malaria is endemic, pregnancy is associated with increased susceptibility to malaria. It is generally agreed that this risk ends with delivery and decreases with the number of pregnancies. Our study aimed to demonstrate relationships between malarial parasitaemia and age, gravidity and anaemia in pregnant women in Libreville, the capital city of Gabon. METHODS: Peripheral blood was collected from 311 primigravidae and women in their second pregnancy. Thick blood smears were checked, as were the results of haemoglobin electrophoresis. We also looked for the presence of anaemia, fever, and checked whether the volunteers had had chemoprophylaxis. The study was performed in Gabon where malaria transmission is intense and perennial. RESULTS: A total of 177 women (57%) had microscopic parasitaemia; 139 (64%)of them were primigravidae, 38 (40%) in their second pregnancy and 180 (64%) were teenagers. The parasites densities were also higher in primigravidae and teenagers. The prevalence of anaemia was 71% and was associated with microscopic Plasmodium falciparum parasitaemia: women with moderate or severe anaemia had higher parasite prevalences and densities. However, the sickle cell trait, fever and the use of chemoprophylaxis did not have a significant association with the presence of P. falciparum. CONCLUSIONS: These results suggest that the prevalence of malaria and the prevalence of anaemia, whether associated with malaria or not, are higher in pregnant women in Gabon. Primigravidae and young pregnant women are the most susceptible to infection. It is, therefore, urgent to design an effective regimen of malaria prophylaxis for this high risk population.

Adolescent↗

PubMed2003

Antibody responses to Plasmodium falciparum merozoite surface protein-1 and efficacy of amodiaquine in Gabonese children with P. falciparum malaria.

The relationship between the efficacy of amodiaquine for the treatment of uncomplicated Plasmodium falciparum malaria and preexisting antibodies against merozoite surface protein (MSP)-1, a blood-stage P. falciparum antigen, was investigated. The immunoglobulin G antibody response to different MSP-1 recombinant proteins was evaluated in plasma samples from Gabonese children with uncomplicated malaria who were treated with amodiaquine. The prevalence of anti-MSP-1 antibodies was similar among patients with either parasitological and clinical cure after treatment (n=102) or treatment failure (n=51) by day 28 (83% in both groups). However, associations between antibody responses to K1 and MAD20 allelic families and therapeutic success were found (P< .001 and P= .034, respectively). A high proportion of plasma samples recognizing several antigens was found in the cured group. This association was significant even when data were stratified by age, particularly for the K1 family antigens (P= .029). These results suggest that humoral immune responses play a supportive role in the efficacy of amodiaquine treatment.

Amodiaquine↗

PubMed2003

Short-course artesunate treatment of uncomplicated Plasmodium falciparum malaria in Gabon.

Artesunate is one of the most important antimalarial agents available, since it is effective against parasites that have developed resistance to conventional antimalarials in sub-Saharan Africa. Antimalarial combination chemotherapies with artesunate (4 mg/kg of body weight once daily for 3 days) as one partner have been proposed. However, the efficacy of a 3-day course of artesunate alone has never been evaluated in individuals in Africa (which has 90% of the worldwide malaria burden) living in regions of hyperendemicity, where a considerable degree of immunity might substantially enhance the efficacy of short courses of artesunate compared to those in regions where the levels of endemicity are low. This lack of information does not permit a systematic assessment of the value of artesunate-based combination chemotherapies in Africa. Therefore, we studied the efficacy and safety of a 3-day course of artesunate (4 mg/kg of body weight, orally, once daily) for the treatment of uncomplicated Plasmodium falciparum malaria in Gabonese patients aged 4 to 15 years (n = 50). Artesunate was well tolerated, and no severe adverse event was reported. Parasite elimination was rapid and was achieved in all patients within < or =72 h (geometric mean time to elimination, 34 h). The PCR-corrected cure rate by day 14 was 92% (46 of 50 patients), but it dropped to 72% (36 of 50 patients) by day 28. We conclude that a 3-day course of artesunate fails to achieve sufficiently high cure rates for uncomplicated falciparum malaria in Gabonese children.

Adolescent↗

PubMed2002

Fosmidomycin for malaria.

Safe and effective antimalarial drugs with new methods of action are urgently needed. Fosmidomycin inhibits the synthesis of isoprenoid by Plasmodium falciparum, and suppresses the growth of multidrug-resistant strains in vitro. Our aim was to assess the efficacy and tolerability of fosmidomycin in adults with malaria in Gabon. We administered the drug for 5, 4, or 3 days (1.2 g every 8 h), in nine, eight, and ten evaluable patients, respectively. All treatment regimens were well tolerated. Cure rates by day 14 were 89% (eight of nine), 88% (seven of eight), and 60% (six of ten), for treatment durations of 5, 4, and 3 days, respectively. These data suggest that fosmidomycin is a safe and effective treatment for uncomplicated malaria if given for 4 days or more.

Adult↗

PubMed2002

Efficacy of atovaquone/proguanil for malaria prophylaxis in children and its effect on the immunogenicity of live oral typhoid and cholera vaccines.

A double-blind, placebo-controlled study was conducted to measure the impact of malaria prophylaxis with atovaquone/proguanil (A-P) on the immunogenicity of vaccines against typhoid fever and cholera, Salmonella serotype Typhi Ty21a and Vibrio cholerae CVD103-HgR, respectively. A total of 330 Gabonese schoolchildren were assigned to receive either A-P or placebo for 12 weeks. Vaccination occurred 3 weeks after the start of prophylaxis, and immunogenicity was assessed 4 weeks after vaccination. The protective efficacy of A-P against Plasmodium falciparum malaria was of 97% (95% confidence interval, 79%-100%). The 2 treatment groups did not differ significantly with regard to changes in antibody titers after vaccination (P=.96 for anti-S. Typhi IgG antibodies, P=.07 for anti-S. Typhi IgA antibodies, and P=.64 for vibriocidal antibodies). The A-P combination was highly effective for malaria prophylaxis, without interfering with the in vivo immunogenicity of CVD103-HgR and Ty21a vaccines, and it could therefore be simultaneously administered with these vaccines.

Administration, Oral↗

PubMedDate not supplied

Severe malarial anemia associated with increased soluble Fas ligand (sFasL) concentrations in Gabonese children.

To investigate if severe malarial anemia is associated with specific cytokine overproduction, we evaluated serum levels of soluble Fas ligand (sFasL), tumor necrosis factor (TNF-alpha) and interleukin-10 (IL-10) from three groups of young children with Plasmodium falciparum infection (asymptomatic cases, uncomplicated malaria cases and severe malarial anemia cases), in a hyperendemic area of Gabon. In uncomplicated cases, only TNF levels were significantly (p < 0.001) increased in comparison to asymptomatic cases with P. falciparum infection. High levels of sFasL, TNF-alpha and IL-10 were associated with low hemoglobin concentrations, sFasL levels were significantly higher in children with severe malarial anemia (p < 0.001) as compared to both other groups. The parasite density was positively correlated with IL-10, TNF-alpha and sFasL levels. TNF-alpha and sFasL, but not IL-10 or parasitemia, were independent predictors of hemoglobin concentrations. These results suggest that, in malaria, a specific dysregulation of the cytokine balance may lead to complications such as severe anemia.

Acute Disease↗