Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Yves Claeys is active.

Publication


Featured researches published by Yves Claeys.


The New England Journal of Medicine | 2016

Evaluation of Convalescent Plasma for Ebola Virus Disease in Guinea

J. van Griensven; Tansy Edwards; X de Lamballerie; Malcolm G. Semple; Pierre Gallian; Sylvain Baize; Peter Horby; Hervé Raoul; N Magassouba; Annick Antierens; C Lomas; O Faye; Amadou A. Sall; Katrien Fransen; Jozefien Buyze; Raffaella Ravinetto; Pierre Tiberghien; Yves Claeys; M De Crop; Lutgarde Lynen; Elhadj Ibrahima Bah; Peter G. Smith; Alexandre Delamou; A. De Weggheleire; Nyankoye Yves Haba

BACKGROUND In the wake of the recent outbreak of Ebola virus disease (EVD) in several African countries, the World Health Organization prioritized the evaluation of treatment with convalescent plasma derived from patients who have recovered from the disease. We evaluated the safety and efficacy of convalescent plasma for the treatment of EVD in Guinea. METHODS In this nonrandomized, comparative study, 99 patients of various ages (including pregnant women) with confirmed EVD received two consecutive transfusions of 200 to 250 ml of ABO-compatible convalescent plasma, with each unit of plasma obtained from a separate convalescent donor. The transfusions were initiated on the day of diagnosis or up to 2 days later. The level of neutralizing antibodies against Ebola virus in the plasma was unknown at the time of administration. The control group was 418 patients who had been treated at the same center during the previous 5 months. The primary outcome was the risk of death during the period from 3 to 16 days after diagnosis with adjustments for age and the baseline cycle-threshold value on polymerase-chain-reaction assay; patients who had died before day 3 were excluded. The clinically important difference was defined as an absolute reduction in mortality of 20 percentage points in the convalescent-plasma group as compared with the control group. RESULTS A total of 84 patients who were treated with plasma were included in the primary analysis. At baseline, the convalescent-plasma group had slightly higher cycle-threshold values and a shorter duration of symptoms than did the control group, along with a higher frequency of eye redness and difficulty in swallowing. From day 3 to day 16 after diagnosis, the risk of death was 31% in the convalescent-plasma group and 38% in the control group (risk difference, -7 percentage points; 95% confidence interval [CI], -18 to 4). The difference was reduced after adjustment for age and cycle-threshold value (adjusted risk difference, -3 percentage points; 95% CI, -13 to 8). No serious adverse reactions associated with the use of convalescent plasma were observed. CONCLUSIONS The transfusion of up to 500 ml of convalescent plasma with unknown levels of neutralizing antibodies in 84 patients with confirmed EVD was not associated with a significant improvement in survival. (Funded by the European Unions Horizon 2020 Research and Innovation Program and others; ClinicalTrials.gov number, NCT02342171.).


The New England Journal of Medicine | 2016

Four Artemisinin-Based Treatments in African Pregnant Women with Malaria.

Pekyi D; Ampromfi Aa; Halidou Tinto; Maminata Traoré-Coulibaly; Marc C. Tahita; Innocent Valea; Mwapasa; Linda Kalilani-Phiri; Gertrude Kalanda; Mwayiwawo Madanitsa; Raffaella Ravinetto; Theonest Mutabingwa; Gbekor P; Harry Tagbor; Gifty Antwi; Joris Menten; De Crop M; Yves Claeys; Céline Schurmans; Van Overmeir C; Kamala Thriemer; Van Geertruyden Jp; Umberto D'Alessandro; Michael Nambozi; Modest Mulenga; Sebastian Hachizovu; Jean-Bertin Kabuya; Joyce Mulenga

BACKGROUND Information regarding the safety and efficacy of artemisinin combination treatments for malaria in pregnant women is limited, particularly among women who live in sub-Saharan Africa. METHODS We conducted a multicenter, randomized, open-label trial of treatments for malaria in pregnant women in four African countries. A total of 3428 pregnant women in the second or third trimester who had falciparum malaria (at any parasite density and regardless of symptoms) were treated with artemether-lumefantrine, amodiaquine-artesunate, mefloquine-artesunate, or dihydroartemisinin-piperaquine. The primary end points were the polymerase-chain-reaction (PCR)-adjusted cure rates (i.e., cure of the original infection; new infections during follow-up were not considered to be treatment failures) at day 63 and safety outcomes. RESULTS The PCR-adjusted cure rates in the per-protocol analysis were 94.8% in the artemether-lumefantrine group, 98.5% in the amodiaquine-artesunate group, 99.2% in the dihydroartemisinin-piperaquine group, and 96.8% in the mefloquine-artesunate group; the PCR-adjusted cure rates in the intention-to-treat analysis were 94.2%, 96.9%, 98.0%, and 95.5%, respectively. There was no significant difference among the amodiaquine-artesunate group, dihydroartemisinin-piperaquine group, and the mefloquine-artesunate group. The cure rate in the artemether-lumefantrine group was significantly lower than that in the other three groups, although the absolute difference was within the 5-percentage-point margin for equivalence. The unadjusted cure rates, used as a measure of the post-treatment prophylactic effect, were significantly lower in the artemether-lumefantrine group (52.5%) than in groups that received amodiaquine-artesunate (82.3%), dihydroartemisinin-piperaquine (86.9%), or mefloquine-artesunate (73.8%). No significant difference in the rate of serious adverse events and in birth outcomes was found among the treatment groups. Drug-related adverse events such as asthenia, poor appetite, dizziness, nausea, and vomiting occurred significantly more frequently in the mefloquine-artesunate group (50.6%) and the amodiaquine-artesunate group (48.5%) than in the dihydroartemisinin-piperaquine group (20.6%) and the artemether-lumefantrine group (11.5%) (P<0.001 for comparison among the four groups). CONCLUSIONS Artemether-lumefantrine was associated with the fewest adverse effects and with acceptable cure rates but provided the shortest post-treatment prophylaxis, whereas dihydroartemisinin-piperaquine had the best efficacy and an acceptable safety profile. (Funded by the European and Developing Countries Clinical Trials Partnership and others; ClinicalTrials.gov number, NCT00852423.).


Clinical Trials | 2016

Design and analysis considerations in the Ebola_Tx trial evaluating convalescent plasma in the treatment of Ebola virus disease in Guinea during the 2014–2015 outbreak

Tansy Edwards; Malcolm G. Semple; Anja De Weggheleire; Yves Claeys; Maaike De Crop; Joris Menten; Raffaella Ravinetto; Sarah Temmerman; Lutgarde Lynen; Elhadj Ibrahima Bah; Peter G. Smith; Johan van Griensven

The Ebola virus disease outbreak in 2014–2015 led to a huge caseload with a high case fatality rate. No specific treatments were available beyond supportive care for conditions such as dehydration and shock. Evaluation of treatment with convalescent plasma from Ebola survivors was identified as a priority. We evaluated this intervention in an emergency setting, where randomization was unacceptable. The original trial design was an open-label study comparing patients receiving convalescent plasma and supportive care to patients receiving supportive care alone. The comparison group comprised patients recruited at the start of the trial before convalescent plasma became available, as well as patients presenting during the trial for whom there was insufficient blood group–compatible plasma or no staffing capacity to provide additional transfusions. However, during the trial, convalescent plasma was available to treat all new patients. The design was changed to use a comparator group comprising patients previously treated at the same Ebola treatment center prior to the start of the trial. In the analysis, it was planned to adjust for any differences in prognostic variables between intervention and comparison groups, specifically baseline polymerase chain reaction cycle threshold and age. In addition, adjustment was planned for other potential confounders, identified in the analysis, such as patient presenting symptoms and time to treatment seeking. Because plasma treatment started up to 3 days after diagnosis and we could not define a similar time-point for the comparator group, patients who died before the third day after confirmation of diagnosis were excluded from both intervention and comparison groups in a per-protocol analysis. Some patients received additional experimental treatments soon after plasma treatment, and these were excluded. We also analyzed mortality including all patients from the time of confirmed diagnosis, irrespective of whether those in the trial series actually received plasma, as an intention-to-treat analysis. Per-protocol and intention-to-treat approaches gave similar conclusions. An important caveat in the interpretation of the findings is that it is unlikely that all potential sources of confounding, such as any variation in supportive care over time, were eliminated. Protocols and electronic data capture systems have now been extensively field-tested for emergency evaluation of treatment with convalescent plasma. Ongoing studies seek to quantify the level of neutralizing antibodies in different plasma donations to determine whether this influences the response and survival of treated patients.


PLOS ONE | 2014

Safety of Daily Co-Trimoxazole in Pregnancy in an Area of Changing Malaria Epidemiology: A Phase 3b Randomized Controlled Clinical Trial

Christine Manyando; Eric M. Njunju; David Mwakazanga; Gershom Chongwe; Rhoda Mkandawire; D. Champo; Modest Mulenga; Maaike De Crop; Yves Claeys; Raffaella Ravinetto; Chantal Van Overmeir; Umberto D’Alessandro; Jean-Pierre Van Geertruyden

Introduction Antibiotic therapy during pregnancy may be beneficial and impacts positively on the reduction of adverse pregnancy outcomes. No studies have been done so far on the effects of daily Co-trimoxazole (CTX) prophylaxis on birth outcomes. A phase 3b randomized trial was conducted to establish that daily CTX in pregnancy is not inferior to SP intermittent preventive treatment (IPT) in reducing placental malaria; preventing peripheral parasitaemia; preventing perinatal mortality and also improving birth weight. To establish its safety on the offspring by measuring the gestational age and birth weight at delivery, and compare the safety and efficacy profile of CTX to that of SP. Methods Pregnant women (HIV infected and uninfected) attending antenatal clinic were randomized to receive either daily CTX or sulfadoxine-pyrimethamine as per routine IPT. Safety was assessed using standard and pregnancy specific measurements. Women were followed up monthly until delivery and then with their offspring up to six weeks after delivery. Results Data from 346 pregnant women (CTX = 190; SP = 156) and 311 newborns (CTX = 166 and SP = 145) showed that preterm deliveries (CTX 3.6%; SP 3.0%); still births (CTX 3.0%; SP 2.1%), neonatal deaths (CTX 0%; SP 1.4%), and spontaneous abortions (CTX 0.6%; SP 0%) were similar between study arms. The low birth weight rates were 9% for CTX and 13% for SP. There were no birth defects reported. Both drug exposure groups had full term deliveries with similar birth weights (mean of 3.1 Kg). The incidence and severity of AEs in the two groups were comparable. Conclusion Exposure to daily CTX in pregnancy may not be associated with particular safety risks in terms of birth outcomes such as preterm deliveries, still births, neonatal deaths and spontaneous abortions compared to SP. However, more data are required on CTX use in pregnant women both among HIV infected and un-infected individuals. Trial Registration Clinicaltrials.gov NCT00711906.


Reproductive Health | 2015

Safe and efficacious artemisinin-based combination treatments for African pregnant women with malaria: a multicentre randomized control trial

Michael Nambozi; Modest Mulenga; Tinto Halidou; Harry Tagbor; Victor Mwapasa; Linda Kalilani Phiri; Gertrude Kalanda; Innocent Valea; Maminata Traore; David Mwakazanga; Yves Claeys; Céline Schurmans; Maaike De Crop; Joris Menten; Raffaella Ravinetto; Kamala Thriemer; Jean-Pierre Van Geertruyden; Theonest Mutabingwa; Umberto D’Alessandro

BackgroundAsymptomatic and symptomatic malaria during pregnancy has consequences for both mother and her offspring. Unfortunately, there is insufficient information on the safety and efficacy of most antimalarials in pregnancy. Indeed, clinical trials assessing antimalarial treatments systematically exclude pregnancy for fear of teratogenicity and embryotoxicity. The little available information originates from South East Asia while in sub-Saharan Africa such information is still limited and needs to be provided.DesignA Phase 3, non-inferiority, multicentre, randomized, open-label clinical trial on safety and efficacy of 4 ACT when administered during pregnancy was carried out in 4 African countries: Burkina Faso, Ghana, Malawi and Zambia. This is a four arm trial using a balanced incomplete block design. Pregnant women diagnosed with malaria are randomised to receive either amodiaquine-artesunate (AQ-AS), dihydroartemisinin-piperaquine (DHA-PQ), artemether-lumefantrine (AL), or mefloquine-artesunate (MQAS). They are actively followed up until day 63 post-treatment and then monthly until 4–6 weeks post-delivery. The offspring is visited at the time of the first birthday. The primary endpoint is treatment failure (PCR adjusted) at day 63 and safety profiles. Secondary endpoints included PCR unadjusted treatment failure up to day 63, gametocyte carriage, Hb changes, placenta malaria, mean birth weight and low birth weight. The primary statistical analysis will use the combined data from all 4 centres, with adjustment for any centre effects, using an additive model for the response rates. This will allow the assessment of all 6 possible pair-wise treatment comparisons using all available data.DiscussionThe strength of this trial is the involvement of several African countries, increasing the generalisability of the results. In addition, it assesses most ACTs currently available, determining their relative ‘-value-’ compared to others. The balanced incomplete block design was chosen because using all 4-arms in each site would have increased complexity in terms of implementation. Excluding HIV-positive pregnant women on antiretroviral drugs may be seen as a limitation because of the possible interactions between antiretroviral and antimalarial treatments. Nevertheless, the results of this trial will provide the evidence base for the formulation of malaria treatment policy for pregnant women in sub-Saharan Africa.Trial registrationNCT00852423


Tropical Medicine & International Health | 2012

Treatment outcomes for human African Trypanosomiasis in the Democratic Republic of the Congo: analysis of routine program data from the world’s largest sleeping sickness control program

Epco Hasker; A. Mpanya; J. Makabuza; F. Mbo; C. Lumbala; J. Kumpel; Yves Claeys; Victor Kande; Raffaella Ravinetto; Joris Menten; Pascal Lutumba; Marleen Boelaert

Objective  To enable the human African trypanosomiasis (HAT) control program of the Democratic Republic of the Congo to generate data on treatment outcomes, an electronic database was developed. The database was piloted in two provinces, Bandundu and Kasai Oriental. In this study, we analysed routine data from the two provinces for the period 2006–2008.


Trials | 2016

Perspectives on the design and methodology of periconceptional nutrient supplementation trials.

Bernard J. Brabin; Sabine Gies; Stephen Owens; Yves Claeys; Umberto D’Alessandro; Halidou Tinto; Loretta Brabin

Periconceptional supplementation could extend the period over which maternal and fetal nutrition is improved, but there are many challenges facing early-life intervention studies. Periconceptional trials differ from pregnancy supplementation trials, not only because of the very early or pre-gestational timing of nutrient exposure but also because they generate subsidiary information on participants who remain non-pregnant. The methodological challenges are more complex although, if well designed, they provide opportunities to evaluate concurrent hypotheses related to the health of non-pregnant women, especially nulliparous adolescents. This review examines the framework of published and ongoing randomised trial designs. Four cohorts typically arise from the periconceptional trial design — two of which are non-pregnant and two are pregnant — and this structure provides assessment options related to pre-pregnant, maternal, pregnancy and fetal outcomes. Conceptually the initial decision for single or micronutrient intervention is central — as is the choice of dosage and content — in order to establish a comparative framework across trials, improve standardisation, and facilitate interpretation of mechanistic hypotheses. Other trial features considered in the review include: measurement options for baseline and outcome assessments; adherence to long-term supplementation; sample size considerations in relation to duration of nutrient supplementation; cohort size for non-pregnant and pregnant cohorts as the latter is influenced by parity selection; integrating qualitative studies and data management issues. Emphasis is given to low resource settings where high infection rates and the possibility of nutrient-infection interactions may require appropriate safety monitoring. The focus is on pragmatic issues that may help investigators planning a periconceptional trial.


The Journal of Infectious Diseases | 2018

Effects of Weekly Iron and Folic Acid Supplements on Malaria Risk in Nulliparous Women in Burkina Faso: A Periconceptional, Double-Blind, Randomized Controlled Noninferiority Trial

Sabine Gies; Salou Diallo; Stephen A Roberts; Adama Kazienga; Matthew Powney; Loretta Brabin; Sayouba Ouedraogo; Dorine W. Swinkels; Anneke Geurts-Moespot; Yves Claeys; Umberto D’Alessandro; Halidou Tinto; Brian Faragher; Bernard Brabin

Weekly iron supplementation, given to young nulliparous women living in a malaria-endemic area, neither improved iron status nor increased malaria risk, suggesting that current iron recommendations may need revisiting for these women.


BMC Medicine | 2017

Effects of long-term weekly iron and folic acid supplementation on lower genital tract infection – a double blind, randomised controlled trial in Burkina Faso

Loretta Brabin; Stephen A Roberts; Sabine Gies; Andrew Nelson; Salou Diallo; Christopher J. Stewart; Adama Kazienga; Julia Birtles; Sayouba Ouedraogo; Yves Claeys; Halidou Tinto; Umberto D’Alessandro; E. Brian Faragher; Bernard J. Brabin


Malawi Medical Journal | 2016

Four artemisinin-based treatments in African pregnant women with malaria

Divine Pekyi; Akua A. Ampromfi; Halidou Tinto; Maminata Traoré-Coulibaly; Marc C. Tahita; Innocent Valea; Victor Mwapasa; Linda Kalilani-Phiri; Gertrude Kalanda; Mwayiwawo Madanitsa; Raffaella Ravinetto; Theonest Mutabingwa; Prosper Gbekor; Harry Tagbor; Gifty Antwi; Joris Menten; Maaike De Crop; Yves Claeys; Céline Schurmans; Chantal Van Overmeir; Kamala Thriemer; Jean-Pierre Van Geertruyden; Umberto D’Alessandro; Michael Nambozi; Modest Mulenga; Sebastian Hachizovu; Jean-Bertin Kabuya; Joyce Mulenga

Collaboration


Dive into the Yves Claeys's collaboration.

Top Co-Authors

Avatar

Raffaella Ravinetto

Institute of Tropical Medicine Antwerp

View shared research outputs
Top Co-Authors

Avatar

Joris Menten

Institute of Tropical Medicine Antwerp

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Modest Mulenga

Zambian Ministry of Health

View shared research outputs
Top Co-Authors

Avatar

Céline Schurmans

Institute of Tropical Medicine Antwerp

View shared research outputs
Top Co-Authors

Avatar

Halidou Tinto

Institute of Tropical Medicine Antwerp

View shared research outputs
Top Co-Authors

Avatar

Maaike De Crop

Institute of Tropical Medicine Antwerp

View shared research outputs
Top Co-Authors

Avatar

Kamala Thriemer

Charles Darwin University

View shared research outputs
Top Co-Authors

Avatar

Innocent Valea

Institute of Tropical Medicine Antwerp

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge