Multi Disease Surveillance Center

Ouagadougou, Burkina Faso

Multi Disease Surveillance Center

Ouagadougou, Burkina Faso
Time filter
Source Type

Traore M.O.,Direction Nationale de la Sante | Sarr M.D.,Ministere de la Sante et de la Prevention | Badji A.,Ministere de la Sante et de la Prevention | Bissan Y.,Multi disease Surveillance Center | And 8 more authors.
PLoS Neglected Tropical Diseases | Year: 2012

Background: Mass treatment with ivermectin controls onchocerciasis as a public health problem, but it was not known if it could also interrupt transmission and eliminate the parasite in endemic foci in Africa where vectors are highly efficient. A longitudinal study was undertaken in three hyperendemic foci in Mali and Senegal with 15 to 17 years of annual or six-monthly ivermectin treatment in order to assess residual levels of infection and transmission, and test whether treatment could be safely stopped. This article reports the results of the final evaluations up to 5 years after the last treatment. Methodology/Principal Findings: Skin snip surveys were undertaken in 131 villages where 29,753 people were examined and 492,600 blackflies were analyzed for the presence of Onchocerca volvulus larva using a specific DNA probe. There was a declining trend in infection and transmission levels after the last treatment. In two sites the prevalence of microfilaria and vector infectivity rate were zero 3 to 4 years after the last treatment. In the third site, where infection levels were comparatively high before stopping treatment, there was also a consistent decline in infection and transmission to very low levels 3 to 5 years after stopping treatment. All infection and transmission indicators were below postulated thresholds for elimination. Conclusion/Significance: The study has established the proof of principle that onchocerciasis elimination with ivermectin treatment is feasible in at least some endemic foci in Africa. The study results have been instrumental for the current evolution from onchocerciasis control to elimination in Africa. © 2012 Traore et al.

Kristiansen P.A.,Norwegian Institute of Public Health | Diomande F.,WHO Inter Country Support Team | Diomande F.,Centers for Disease Control and Prevention | Ouedraogo R.,University of Ouagadougou | And 12 more authors.
Journal of Clinical Microbiology | Year: 2012

Neisseria lactamica is a true commensal bacterium occupying the same ecological niche as the pathogenic Neisseria meningitidis, which is responsible for outbreaks and large epidemics, especially in sub-Saharan Africa. To better understand the epidemiology of N. lactamica in Africa and its relationship to N. meningitidis, we studied N. lactamica carriage in 1- to 29-year-old people living in three districts of Burkina Faso from 2009 to 2011. N. lactamica was detected in 18.2% of 45,847 oropharyngeal samples. Carriage prevalence was highest among the 2-year-olds (40.1%) and decreased with age. Overall prevalence was higher for males (19.1%) than females (17.5%) (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.04 to 1.18), while among the 18- to 29-year-olds, carriage prevalence was significantly higher in women (9.1%) than in men (3.9%) (OR, 2.49; 95% CI, 1.94 to 3.19). Carriage prevalence of N. lactamica was remarkably homogeneous in the three districts of Burkina Faso and stable over time, in comparison with carriage of N. meningitidis (P. A. Kristiansen et al., Clin. Vaccine Immunol. 18:435-443, 2011). There was no significant seasonal variation of N. lactamica carriage and no significant change in carriage prevalence after introduction of the serogroup A meningococcal conjugate vaccine, MenAfriVac. Multilocus sequence typing was performed on a selection of 142 isolates. The genetic diversity was high, as we identified 62 different genotypes, of which 56 were new. The epidemiology of N. lactamica carriage and the molecular characteristics of carried isolates were similar to those reported from industrialized countries, in contrast to the particularities of N. meningitidis carriage and disease epidemiology in Burkina Faso. Copyright © 2012, American Society for Microbiology. All Rights Reserved.

Kristiansen P.A.,Norwegian Institute of Public Health | Diomande F.,Ministry of Health | Diomande F.,Centers for Disease Control and Prevention | Ba A.K.,Laboratoire National Of Sante Public | And 22 more authors.
Clinical Infectious Diseases | Year: 2013

Background. The conjugate vaccine against serogroup A Neisseria meningitidis (NmA), MenAfriVac, was first introduced in mass vaccination campaigns of 1-29-year-olds in Burkina Faso in 2010. It is not known whether MenAfriVac has an impact on NmA carriage.Methods. We conducted a repeated cross-sectional meningococcal carriage study in a representative portion of the 1-29-year-old population in 3 districts in Burkina Faso before and up to 13 months after vaccination. One district was vaccinated in September 2010, and the other 2 were vaccinated in December 2010. We analyzed 25 521 oropharyngeal samples, of which 22 093 were obtained after vaccination.Results. In October-November 2010, NmA carriage prevalence in the unvaccinated districts was comparable to the baseline established in 2009, but absent in the vaccinated district. Serogroup X N. meningitidis (NmX) dominated in both vaccinated and unvaccinated districts. With 4 additional sampling campaigns performed throughout 2011 in the 3 districts, overall postvaccination meningococcal carriage prevalence was 6.95%, with NmX dominating but declining for each campaign (from 8.66% to 1.97%). Compared with a baseline NmA carriage prevalence of 0.39%, no NmA was identified after vaccination. Overall vaccination coverage in the population sampled was 89.7%, declining over time in 1-year-olds (from 87.1% to 26.5%), as unvaccinated infants reached 1 year of age. NmA carriage was eliminated in both the vaccinated and unvaccinated population from 3 weeks up to 13 months after mass vaccination (P =. 003).Conclusions. The disappearance of NmA carriage among both vaccinated and unvaccinated populations is consistent with a vaccine-induced herd immunity effect. © 2012 The Author 2012.

Kristiansen P.A.,Norwegian Institute of Public Health | Diomande F.,WHO Inter Country Support Team | Diomande F.,Centers for Disease Control and Prevention | Wei S.C.,Centers for Disease Control and Prevention | And 19 more authors.
Clinical and Vaccine Immunology | Year: 2011

The serogroup A meningococcal conjugate vaccine MenAfriVac has the potential to confer herd immunity by reducing carriage prevalence of epidemic strains. To better understand this phenomenon, we initiated a meningococcal carriage study to determine the baseline carriage rate and serogroup distribution before vaccine introduction in the 1- to 29-year old population in Burkina Faso, the group chosen for the first introduction of the vaccine. A multiple cross-sectional carriage study was conducted in one urban and two rural districts in Burkina Faso in 2009. Every 3 months, oropharyngeal samples were collected from >5,000 randomly selected individuals within a 4-week period. Isolation and identification of the meningococci from 20,326 samples were performed by national laboratories in Burkina Faso. Confirmation and further strain characterization, including genogrouping, multilocus sequence typing, and porA-fetA sequencing, were performed in Norway. The overall carriage prevalence for meningococci was 3.98%; the highest prevalence was among the 15- to 19-year-olds for males and among the 10- to 14-year-olds for females. Serogroup Y dominated (2.28%), followed by serogroups X (0.44%), A (0.39%), and W135 (0.34%). Carriage prevalence was the highest in the rural districts and in the dry season, but serogroup distribution also varied by district. A total of 29 sequence types (STs) and 51 porA-fetA combinations were identified. The dominant clone was serogroup Y, ST-4375, P1.5-1,2-2/F5-8, belonging to the ST-23 complex (47%). All serogroup A isolates were ST-2859 of the ST-5 complex with P1.20,9/F3-1. This study forms a solid basis for evaluating the impact of MenAfriVac introduction on serogroup A carriage. Copyright © 2011, American Society for Microbiology. All Rights Reserved.

Sam-Wobo S.O.,Abeokuta Federal University of Agriculture | Adeleke M.A.,Osun State University | Jayeola O.A.,Abeokuta Federal University of Agriculture | Adeyi A.O.,University of Ibadan | And 8 more authors.
International Journal of Tropical Insect Science | Year: 2013

Seasonal fluctuations of the Simulium damnosum Theobald complex and the prevalence of Onchocerca volvulus Bickel in blackflies caught in river systems bordering the Nigeria-Benin border were assessed for their direct impact on the epidemiology of onchocerciasis in South-western Nigeria. Entomological evaluation and heteroduplex assay (HDA) techniques were performed on flies caught in the eight capture points in the Ogun and Yewa river systems between October and December 2007, July and December 2008 and May and December 2009. A total of 5789 blackflies were caught on human bait, of which 727 (12.6%) flies were captured in 2007, 1723 (29.8%) in 2008 and 3339 (57.6%) in 2009. The majority of flies caught during the study were forest flies representing 90.3% of the total catch while savanna flies constituted 9.7%. Proportions of parous to nulliparous flies were low in all the catching points (31.1 and 68.9%, respectively). Of the 5789 flies dissected, 11 (0.2%) flies were infected with Onchocerca parasites with nine of the infected flies having L3 head parasites. The HDA results revealed that the Beffa form of S. soubrense was the dominant cytospecies present (87.1%) in all the capture sites when compared with 12.9% of S. damnosum s.s. The low level of infectivity of flies may therefore indicate a low transmission level of onchocerciasis in the communities along the Ogun and Yewa river systems. However, there is a need for constant surveillance on species composition and fly infectivity in the river systems along the borders of Nigeria-Benin Republic. © 2013 icipe.

Gopal H.,National Polytechnic Institute of Mexico | Hassan H.K.,University of South Florida | Rodriguez-Perez M.A.,National Polytechnic Institute of Mexico | Toe L.D.,Multi Disease Surveillance Center | And 2 more authors.
PLoS Neglected Tropical Diseases | Year: 2012

Background: Entomological surveys of Simulium vectors are an important component in the criteria used to determine if Onchocerca volvulus transmission has been interrupted and if focal elimination of the parasite has been achieved. However, because infection in the vector population is quite rare in areas where control has succeeded, large numbers of flies need to be examined to certify transmission interruption. Currently, this is accomplished through PCR pool screening of large numbers of flies. The efficiency of this process is limited by the size of the pools that may be screened, which is in turn determined by the constraints imposed by the biochemistry of the assay. The current method of DNA purification from pools of vector black flies relies upon silica adsorption. This method can be applied to screen pools containing a maximum of 50 individuals (from the Latin American vectors) or 100 individuals (from the African vectors). Methodology/Principal Findings: We have evaluated an alternative method of DNA purification for pool screening of black flies which relies upon oligonucleotide capture of Onchocerca volvulus genomic DNA from homogenates prepared from pools of Latin American and African vectors. The oligonucleotide capture assay was shown to reliably detect one O. volvulus infective larva in pools containing 200 African or Latin American flies, representing a two-four fold improvement over the conventional assay. The capture assay requires an equivalent amount of technical time to conduct as the conventional assay, resulting in a two-four fold reduction in labor costs per insect assayed and reduces reagent costs to $3.81 per pool of 200 flies, or less than $0.02 per insect assayed. Conclusions/Significance: The oligonucleotide capture assay represents a substantial improvement in the procedure used to detect parasite prevalence in the vector population, a major metric employed in the process of certifying the elimination of onchocerciasis. © 2012 Gopal et al.

Weidmann M.,University of Gottingen | Sall A.A.,L Institute Pasteur Of Dakar | Manuguerra J.-C.,Institute Pasteur Paris | Koivogui L.,University Of Conakry | And 5 more authors.
Virology Journal | Year: 2011

Information on the replication of viral haemorrhagic fever viruses is not readily available and has never been analysed in a comparative approach. Here, we compared the cell culture growth characteristics of haemorrhagic fever viruses (HFV), of the Arenaviridae, Filoviridae, Bunyaviridae, and Flavivridae virus families by performing quantitative analysis of cell culture supernatants by (i) electron microscopy for the quantification of virus particles, (ii) quantitative real time PCR for the quantification of genomes, and (iii) determination of focus forming units by coating fluorescent antibodies to infected cell monolayers for the quantification of virus infectivity. The comparative analysis revealed that filovirus and RVFV replication results in a surplus of genomes but varying degrees of packaging efficiency and infectious particles. More efficient replication and packaging was observed for Lassa virus, and Dengue virus resulting in a better yield of infectious particles while, YFV turned out to be most efficient with only 4 particles inducing one FFU. For Crimean-Congo haemorrhagic fever virus (CCHFV) a surplus of empty shells was observed with only one in 24 particles equipped with a genome. The complete particles turned out to be extraordinarily infectious. © 2011 Weidmann et al; licensee BioMed Central Ltd.

Nikiema A.,University of Ouagadougou | Nikiema A.,Direction des Laboratoires | Toe L.,Multi Disease Surveillance Center | Adjami G.,Multi Disease Surveillance Center | Traore R.O.,University of Ouagadougou
Bulletin de la Societe de Pathologie Exotique | Year: 2010

A prospective study (from August 2006 to April 2007) was carried out with 214 cerebrospinal fluid samples with suspicion of bacterial meningitis. The aim of the study was to assess the effectiveness of the simultaneous detection of Neisseria meningitidis, Streptococcus sp. and Haemophilus influenzae using seminested polymerase chain reaction strategy. Among the 214 samples tested by both PCR and culture, the overall confirmation rate was 64% for PCR and 40.1% for culture (P = 2× 10 -6). Taking culture method as the standard reference, the overall sensitivity of PCR was 98.8% and specificity, 59.4%. The sensitivity of PCR was 100, 97.3 and 100% respectively for N. meningitidis, Streptococcus sp. and H. influenzae with respective specificities of 70, 93.2 and 97.2%. In conclusion, the seminested PCR strategy is a sensitive method and it can be implemented in the reference public health laboratories for an exhaustive microbiological surveillance of bacterial meningitis. © Société de pathologie exotique et Springer-Verlag France 2010.

Loading Multi Disease Surveillance Center collaborators
Loading Multi Disease Surveillance Center collaborators