New lateral flow tests for the diagnosis of (Nm) (serogroups A, C, W, X, and Y), MeningoSpeed, and (Sp), PneumoSpeed, developed to support rapid outbreak detection in Africa, have shown good performance under laboratory conditions. We conducted an independent evaluation of both tests under field conditions in Burkina Faso and Niger, in 2018-2019. The tests were performed in the cerebrospinal fluid of suspected meningitis cases from health centers in alert districts and compared to reverse transcription polymerase chain reaction tests performed at national reference laboratories (NRLs).
View Article and Find Full Text PDFWest Nile virus (WNV), belonging to the family, causes a mosquito-borne disease and shows great genetic diversity, with at least eight different lineages. The Koutango lineage of WNV (WN-KOUTV), mostly associated with ticks and rodents in the wild, is exclusively present in Africa and shows evidence of infection in humans and high virulence in mice. In 2016, in a context of Rift Valley fever (RVF) outbreak in Niger, mosquitoes, biting midges and sandflies were collected for arbovirus isolation using cell culture, immunofluorescence and RT-PCR assays.
View Article and Find Full Text PDFMeningococcal meningitis remains a life-threatening disease worldwide, with high prevalence in the sub-Saharan meningitis belt. A rapid diagnosis is crucial for implementing adapted antimicrobial treatment. We describe the performances of a new immunochromatographic test (MeningoSpeed, BioSpeedia, France) for detecting and grouping Cerebrospinal fluids (CSFs) were collected from 5 African countries and France.
View Article and Find Full Text PDFBackground: The MenAfriNet consortium was established in 2014 to support implementation of case-based meningitis surveillance in 5 countries in the meningitis belt of sub-Saharan Africa: Burkina Faso, Chad, Mali, Niger, and Togo. Assessing surveillance performance is critical for interpretation of the collected data and implementation of future surveillance-strengthening initiatives.
Methods: Detailed epidemiologic and laboratory data were collected on suspected meningitis cases through case-based meningitis surveillance in participating districts in 5 countries.
Despite the introduction of an effective serogroup A conjugate vaccine (MenAfriVac™), sporadic epidemics of other serogroups remain a concern in Africa. Polyvalent meningococcal conjugate (PMC) vaccines may offer alternatives to current strategies that rely on routine infant vaccination with MenAfriVac plus, in the event of an epidemic, district-specific reactive campaigns using polyvalent meningococcal polysaccharide (PMP) vaccines. We developed an agent-based transmission model of in Niger to compare the health effects and costs of current vaccination practice and 3 alternatives.
View Article and Find Full Text PDFRift Valley fever (RVF) is a mosquito-borne viral zoonosis causing abortions and high mortality among animals, whereas in humans, the disease is usually mild or asymptomatic. In September 2016, the Republic of Niger declared the first RVF outbreak in the northern region of Tahoua near the Malian border. This study describes the outbreak and reports the results of serological and molecular investigations of the human and animal samples collected.
View Article and Find Full Text PDFBackground: Antibiotic prophylaxis for contacts of meningitis cases is not recommended during outbreaks in the African meningitis belt. We assessed the effectiveness of single-dose oral ciprofloxacin administered to household contacts and in village-wide distributions on the overall attack rate (AR) in an outbreak of meningococcal meningitis.
Methods And Findings: In this 3-arm, open-label, cluster-randomized trial during a meningococcal meningitis outbreak in Madarounfa District, Niger, villages notifying a suspected case were randomly assigned (1:1:1) to standard care (the control arm), single-dose oral ciprofloxacin for household contacts within 24 hours of case notification, or village-wide distribution of ciprofloxacin within 72 hours of first case notification.
Background: To combat Neisseria meningitidis serogroup A epidemics in the meningitis belt of sub-Saharan Africa, a meningococcal serogroup A conjugate vaccine (MACV) has been progressively rolled out since 2010. We report the first meningitis epidemic in Niger since the nationwide introduction of MACV.
Methods: We compiled and analysed nationwide case-based meningitis surveillance data in Niger.
In 2015, Niger reported the largest epidemic of Neisseria meningitidis serogroup C (NmC) meningitis in sub-Saharan Africa. The NmC epidemic coincided with serogroup W (NmW) cases during the epidemic season, resulting in a total of 9,367 meningococcal cases through June 2015. To clarify the phylogenetic association, genetic evolution, and antibiotic determinants of the meningococcal strains in Niger, we sequenced the genomes of 102 isolates from this epidemic, comprising 81 NmC and 21 NmW isolates.
View Article and Find Full Text PDFWe describe clinical symptoms, case-fatality rates, and prevalence of sequelae during an outbreak of Neisseria meningitidis serogroup C infection in a rural district of Niger. During home visits, we established that household contacts of reported case-patients were at higher risk for developing meningitis than the general population.
View Article and Find Full Text PDFIntroduction: In 2015, a large outbreak of serogroup C meningococcal meningitis hit Niamey, Niger, in response to which a vaccination campaign was conducted late April. Using a case-control study we measured the vaccine effectiveness (VE) of tri - (ACW) and quadrivalent (ACYW) polysaccharide meningococcal vaccines against clinical meningitis among 2-15 year olds in Niamey II district between April 28th and June 30th 2015.
Methods: We selected all clinical cases registered in health centers and conducted a household- vaccination coverage cluster survey (control group).
The Pastorex((R)) (BioRad) rapid agglutination test is one of the main rapid diagnostic tests (RDTs) for meningococcal disease currently in use in the "meningitis belt". Earlier evaluations, performed after heating and centrifugation of cerebrospinal fluid (CSF) samples, under good laboratory conditions, showed high sensitivity and specificity. However, during an epidemic, the test may be used without prior sample preparation.
View Article and Find Full Text PDFIn the African meningitis belt, reported case-fatality ratio (CFR) for meningitis are usually calculated on the basis of presumed cases. We reviewed 3509 presumed cases of bacterial meningitis reported in Niger for which a cerebrospinal fluid (CSF) sample had been tested later at the reference laboratory. The main aetiologies were Neisseria meningitidis (1496 cases), Streptococcus pneumoniae (303 cases) and Haemophilus influenzae (105 cases).
View Article and Find Full Text PDFWe investigated the carriage of serogroup W135 meningococci and its relationship with protective immunity in Niamey. Between February and May 2003, three oropharyngeal swabs and two serum samples were each taken from 287 school children. Serogroup W135 isolates were obtained from 8.
View Article and Find Full Text PDFSince the Neisseria meningitidis serogroup W135 epidemic in Burkina Faso in 2002, the neighbouring countries dread undergoing outbreaks. Niger has strongly enhanced the microbiological surveillance, especially by adding the polymerase chain reaction (PCR) assay to the national framework of the surveillance system. During the 2003 epidemic season, 8113 clinically suspected cases of meningitis were notified and nine districts of the 42 crossed the epidemic threshold, while during the 2004 season, the number of cases was 3521 and four districts notified epidemics.
View Article and Find Full Text PDFTo compensate for the lack of laboratories in remote areas, the national reference laboratory for meningitis in Niger used polymerase chain reaction (PCR) to enhance the surveillance of meningitis caused by Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae. PCR effectively documented the wide geographic spread of N. meningitidis serogroup W135.
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