Center Pour le Developpement des Vaccins Mali

Bamako, Mali

Center Pour le Developpement des Vaccins Mali

Bamako, Mali
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Barth D.D.,University of Cape Town | Engel M.E.,University of Cape Town | Whitelaw A.,Stellenbosch University | Alemseged A.,Jimma University | And 5 more authors.
BMJ Open | Year: 2016

Introduction: Group A α-haemolytic Streptococcus (GAS), a Gram-positive bacterium, also known as Streptococcus pyogenes, causes pyoderma, pharyngitis and invasive disease. Repeated GAS infections may lead to autoimmune diseases such as acute post-streptococcal glomerulonephritis, acute rheumatic fever (ARF) and rheumatic heart disease (RHD). Invasive GAS (iGAS) disease is an important cause of mortality and morbidity worldwide. The burden of GAS infections is, however, unknown in Africa because of lack of surveillance systems. Methods and analysis: The African group A streptococcal infection registry (the AFROStrep study) is a collaborative multicentre study of clinical, microbiological, epidemiological and molecular characteristics for GAS infection in Africa. The AFROStrep registry comprises two components: (1) active surveillance of GAS pharyngitis cases from sentinel primary care centres (non-iGAS) and (2) passive surveillance of iGAS disease from microbiology laboratories. Isolates will also be subjected to DNA isolation to allow for characterisation by molecular methods and cryopreservation for long-term storage. The AFROStrep study seeks to collect comprehensive data on GAS isolates in Africa. The biorepository will serve as a platform for vaccine development in Africa. Ethics and dissemination: Ethics approval for the AFROStrep registry has been obtained from the Human Research Ethics Committee at the University of Cape Town (HREC/REF: R006/2015). Each recruiting site will seek ethics approval from their local ethics' committee. All participants will be required to provide consent for inclusion into the registry as well as for the storage of isolates and molecular investigations to be conducted thereon. Strict confidentiality will be applied throughout. Findings and updates will be disseminated to collaborators, researchers, health planners and colleagues through peer-reviewed journal articles, conference publications and proceedings.


PubMed | Centers for Disease Control and Prevention, University of Barcelona, Maputo Central Hospital, Kenya Medical Research Institute and 2 more.
Type: Journal Article | Journal: PLoS medicine | Year: 2016

The minimally invasive autopsy (MIA) is being investigated as an alternative to complete diagnostic autopsies for cause of death (CoD) investigation. Before potential implementation of the MIA in settings where post-mortem procedures are unusual, a thorough assessment of its feasibility and acceptability is essential.We conducted a socio-behavioural study at the community level to understand local attitudes and perceptions related to death and the hypothetical feasibility and acceptability of conducting MIAs in six distinct settings in Gabon, Kenya, Mali, Mozambique, and Pakistan. A total of 504 interviews (135 key informants, 175 health providers [including formal health professionals and traditional or informal health providers], and 194 relatives of deceased people) were conducted. The constructs willingness to know the CoD and hypothetical acceptability of MIAs were quantified and analysed using the framework analysis approach to compare the occurrence of themes related to acceptability across participants. Overall, 75% (379/504) of the participants would be willing to know the CoD of a relative. The overall hypothetical acceptability of MIA on a relative was 73% (366/504). The idea of the MIA was acceptable because of its perceived simplicity and rapidity and particularly for not mutilating the body. Further, MIAs were believed to help prevent infectious diseases, address hereditary diseases, clarify the CoD, and avoid witchcraft accusations and conflicts within families. The main concerns regarding the procedure included the potential breach of confidentiality on the CoD, the misperception of organ removal, and the incompatibility with some religious beliefs. Formal health professionals were concerned about possible contradictions between the MIA findings and the clinical pre-mortem diagnoses. Acceptability of the MIA was equally high among Christian and Islamic communities. However, in the two predominantly Muslim countries, MIA acceptability was higher in Mali than in Pakistan. While the results of the study are encouraging for the potential use of the MIA for CoD investigation in low-income settings, they remain hypothetical, with a need for confirmation with real-life MIA implementation and in populations beyond Health and Demographic Surveillance System areas.This study showed a high level of interest in knowing the CoD of a relative and a high hypothetical acceptability of MIAs as a tool for CoD investigation across six distinct settings. These findings anticipate potential barriers and facilitators, both at the health facility and community level, essential for local tailoring of recommendations for future MIA implementation.


PubMed | Jimma University, University of Cape Town, Stellenbosch University, Center pour le Developpement des Vaccins Mali and 3 more.
Type: Journal Article | Journal: BMJ open | Year: 2016

Group A -haemolytic Streptococcus (GAS), a Gram-positive bacterium, also known as Streptococcus pyogenes, causes pyoderma, pharyngitis and invasive disease. Repeated GAS infections may lead to autoimmune diseases such as acute post-streptococcal glomerulonephritis, acute rheumatic fever (ARF) and rheumatic heart disease (RHD). Invasive GAS (iGAS) disease is an important cause of mortality and morbidity worldwide. The burden of GAS infections is, however, unknown in Africa because of lack of surveillance systems.The African group A streptococcal infection registry (the AFROStrep study) is a collaborative multicentre study of clinical, microbiological, epidemiological and molecular characteristics for GAS infection in Africa. The AFROStrep registry comprises two components: (1) active surveillance of GAS pharyngitis cases from sentinel primary care centres (non-iGAS) and (2) passive surveillance of iGAS disease from microbiology laboratories. Isolates will also be subjected to DNA isolation to allow for characterisation by molecular methods and cryopreservation for long-term storage. The AFROStrep study seeks to collect comprehensive data on GAS isolates in Africa. The biorepository will serve as a platform for vaccine development in Africa.Ethics approval for the AFROStrep registry has been obtained from the Human Research Ethics Committee at the University of Cape Town (HREC/REF: R006/2015). Each recruiting site will seek ethics approval from their local ethics committee. All participants will be required to provide consent for inclusion into the registry as well as for the storage of isolates and molecular investigations to be conducted thereon. Strict confidentiality will be applied throughout. Findings and updates will be disseminated to collaborators, researchers, health planners and colleagues through peer-reviewed journal articles, conference publications and proceedings.


Tapia M.D.,University of Maryland, Baltimore | Sow S.O.,Center pour le Developpement des Vaccins Mali | Tamboura B.,Center pour le Developpement des Vaccins Mali | Keita M.M.,Center pour le Developpement des Vaccins Mali | And 8 more authors.
Pediatric Infectious Disease Journal | Year: 2015

Background: Group A streptococcus (GAS) pharyngitis is associated with high rates of rheumatic heart disease in developing countries. We sought to identify guidelines for empiric treatment of pharyngitis in low-resource settings. To inform the design of GAS vaccines, we determined the emm types associated with pharyngitis among African schoolchildren. Methods: Surveillance for pharyngitis was conducted among children 5-16 years of age attending schools in Bamako, Mali. Students were encouraged to visit a study clinician when they had a sore throat. Enrollees underwent evaluation and throat swab for isolation of GAS. Strains were emm typed by standard methods. Results: GAS was isolated from 449 (25.5%) of the 1,759 sore throat episodes. Painful cervical adenopathy was identified in 403 children (89.8%) with GAS infection and was absent in 369 uninfected children (28.2%). Emm type was determined in 396 (88.2%) of the 449 culture-positive children; 70 types were represented and 14 types accounted for 49% of isolates. Based on the proportion of the 449 isolates bearing emm types included in the 30-valent vaccine (31.0%) plus nonvaccine types previously shown to react to vaccine-induced bactericidal antibodies (44.1%), the vaccine could protect against almost 75% of GAS infections among Bamako schoolchildren. Conclusions: Two promising strategies could reduce rheumatic heart disease in low-resource settings. Administering antibiotics to children with sore throat and tender cervical adenopathy could treat most GAS-positive children while reducing use of unnecessary antibiotics for uninfected children. Broad coverage against M types associated with pharyngitis in Bamako schoolchildren might be achieved with the 30-valent GAS vaccine under development. © 2015 Wolters Kluwer Health, Inc.


Tennant S.M.,University of Maryland Baltimore County | Diallo S.,Center Pour le Developpement des Vaccins Mali | Levy H.,University of Maryland Baltimore County | Levy H.,Israel Institute for Biological Research | And 10 more authors.
PLoS Neglected Tropical Diseases | Year: 2010

Background: In sub-Saharan Africa, non-typhoidal Salmonella (NTS) are emerging as a prominent cause of invasive disease (bacteremia and focal infections such as meningitis) in infants and young children. Importantly, including data from Mali, three serovars, Salmonella enterica serovar Typhimurium, Salmonella Enteritidis and Salmonella Dublin, account for the majority of non-typhoidal Salmonella isolated from these patients. Methods: We have extended a previously developed series of polymerase chain reactions (PCRs) based on O serogrouping and H typing to identify Salmonella Typhimurium and variants (mostly I 4,[5],12:i:-), Salmonella Enteritidis and Salmonella Dublin. We also designed primers to detect Salmonella Stanleyville, a serovar found in West Africa. Another PCR was used to differentiate diphasic Salmonella Typhimurium and monophasic Salmonella Typhimurium from other O serogroup B, H:i serovars. We used these PCRs to blind-test 327 Salmonella serogroup B and D isolates that were obtained from the blood cultures of febrile patients in Bamako, Mali. Principal Findings: We have shown that when used in conjunction with our previously described O-serogrouping PCR, our PCRs are 100% sensitive and specific in identifying Salmonella Typhimurium and variants, Salmonella Enteritidis, Salmonella Dublin and Salmonella Stanleyville. When we attempted to differentiate 171 Salmonella Typhimurium (I 4,[ 5],12:i:1,2) strains from 52 monophasic Salmonella Typhimurium (I 4,[5],12:i:-) strains, we were able to correctly identify 170 of the Salmonella Typhimurium and 51 of the Salmonella I 4,[5],12:i:- strains. Conclusion: We have described a simple yet effective PCR method to support surveillance of the incidence of invasive disease caused by NTS in developing countries.


Findlow H.,Public Health England | Sow S.,Center Pour le Developpement des Vaccins Mali | Borrow R.,Public Health England | Borrow R.,University of Manchester | And 19 more authors.
Clinical and Vaccine Immunology | Year: 2011

A phase II clinical study was conducted in African toddlers (aged 12 to 23 months), with subjects receiving either investigational meningococcal group A conjugate (PsA-TT), meningococcal ACWY polysaccharide (PsACWY), or Haemophilus influenzae type b (Hib-TT) vaccine. Ten months following vaccination, the 3 study groups were further randomized to receive a dose of PsA-TT, a 1/5 dose of PsACWY, or a dose of Hib-TT vaccine. Group A serum bactericidal antibody (SBA) results have been reported previously, with PsA-TT demonstrating superior immunogenicity versus PsACWY vaccine. Immunogenicity for serogroups W135 and C was assessed by SBA assay to investigate the impact of multiple doses in this age group. Blood samples were taken prior to vaccination, 28 days and 40 weeks post-primary vaccination, and 7 and 28 days post-booster vaccination with a 1/5 dose of PsACWY. Subjects who had previously received a full dose of PsACWY had W135 SBA geometric mean titers (GMTs) of 26.1 and 4.4 at 7 and 28 days post-booster vaccination with a 1/5 PsACWY dose, respectively, whereas the W135 SBA GMTs of naïve subjects at these time points following vaccination with a 1/5 dose of PsACWY were 861.1 and 14.6, respectively. Similar differences were observed for serogroup C, with SBA GMTs of 99 and 5.9 at 7 and 28 days post-booster vaccination with a 1/5 dose of PsACWY, respectively, for naïve subjects, compared to 4.1 and 3.2 for previously vaccinated subjects. Immunologic hyporesponsiveness for groups C and W135 was observed following a full dose of PsACWY vaccine at 12 to 23 months of age and a 1/5 dose of PsACWY 10 months later compared to the case for PsACWY-naïve subjects receiving a 1/5 dose of PsACWY vaccine. Copyright © 2011, American Society for Microbiology. All Rights Reserved.


Orenstein L.A.V.,Emory University | Orenstein E.W.,Emory University | Teguete I.,Gabriel Toure Teaching Hospital | Kodio M.,Center pour le Developpement des Vaccins Mali | And 5 more authors.
PLoS ONE | Year: 2012

Background: Maternal immunization has gained traction as a strategy to diminish maternal and young infant mortality attributable to infectious diseases. Background rates of adverse pregnancy outcomes are crucial to interpret results of clinical trials in Sub-Saharan Africa. Methods: We developed a mathematical model that calculates a clinical trial's expected number of neonatal and maternal deaths at an interim safety assessment based on the person-time observed during different risk windows. This model was compared to crude multiplication of the maternal mortality ratio and neonatal mortality rate by the number of live births. Systematic reviews of severe acute maternal morbidity (SAMM), low birth weight (LBW), prematurity, and major congenital malformations (MCM) in Sub-Saharan African countries were also performed. Findings: Accounting for the person-time observed during different risk periods yields lower, more conservative estimates of expected maternal and neonatal deaths, particularly at an interim safety evaluation soon after a large number of deliveries. Median incidence of SAMM in 16 reports was 40.7 (IQR: 10.6-73.3) per 1,000 total births, and the most common causes were hemorrhage (34%), dystocia (22%), and severe hypertensive disorders of pregnancy (22%). Proportions of liveborn infants who were LBW (median 13.3%, IQR: 9.9-16.4) or premature (median 15.4%, IQR: 10.6-19.1) were similar across geographic region, study design, and institutional setting. The median incidence of MCM per 1,000 live births was 14.4 (IQR: 5.5-17.6), with the musculoskeletal system comprising 30%. Interpretation: Some clinical trials assessing whether maternal immunization can improve pregnancy and young infant outcomes in the developing world have made ethics-based decisions not to use a pure placebo control. Consequently, reliable background rates of adverse pregnancy outcomes are necessary to distinguish between vaccine benefits and safety concerns. Local studies that quantify population-based background rates of adverse pregnancy outcomes will improve safety assessment of interventions during pregnancy. © 2012 Orenstein et al.

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