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BackgroundMeningococcal epidemics in Africa are generally caused by capsular group A strains, but W-135 or X strains also cause epidemics in this region. Factor H–binding protein (fHbp) is a novel antigen being investigated for use in group B vaccines. Little is known about fHbp in strains from other capsular groups MethodsWe investigated fHbp in 35 group A, W-135, and X strains from Africa ResultsThe 22 group A isolates, which included each of the sequence types (STs) responsible for epidemics since 1963, and 4 group X and 3 group W-135 isolates from recent epidemics had genes encoding fHbp in antigenic variant group 1. The remaining 6 W-135 isolates had fHbp variant 2. Within each fHbp variant group, there was 92%–100% amino acid identity, and the proteins expressed conserved epitopes recognized by bactericidal monoclonal antibodies. Serum samples obtained from mice vaccinated with native outer membrane vesicle vaccines from mutants engineered to express fHbp variants had broad bactericidal activity against group A, W-135, or X strains ConclusionsDespite extensive natural exposure of the African population, fHbp is conserved among African strains. A native outer membrane vesicle vaccine that expresses fHbp variants can potentially elicit protective antibodies against strains from all capsular groups that cause epidemics in the region

Background.In the African meningitis belt, Neisseria meningitidis serogroup W135 has emerged as a cause of epidemic disease. The establishment of W135 as the predominant cause of endemic disease has not been described. Methods.We conducted national laboratory–based surveillance for invasive meningococcal disease during 2000–2005. The system was enhanced in 2003 to include clinical data collection of cases from sentinel sites. Isolates were characterized by pulsed-field gel electrophoresis and multilocus sequence typing. Results.A total of 2135 cases of invasive meningococcal disease were reported, of which 1113 (52%) occurred in Gauteng Province, South Africa. In this province, rates of disease increased from 0.8 cases per 100,000 persons in 2000 to 4.0 cases per 100,000 persons in 2005; the percentage due to serogroup W135 increased from 7% (4 of 54 cases) to 75% (221 of 295 cases). The median age of patients infected with serogroup W135 was 5 years (interquartile range, 2–23 years), compared with 21 years (range, 8–26 years) for those infected with serogroup A (P<.001) The incidence of W135 disease increased in all age groups. Rates were highest among infants (age, <1 year), increasing from 5.1 cases per 100,000 persons in 2003 to 21.5 cases per 100,000 persons in 2005. Overall case-fatality rates doubled, from 11% in 2003 to 22% in 2005. Serogroup W135 was more likely to cause meningococcemia than was serogroup A (82 [28%] of 297 cases vs. 11 [8%] of 141 cases; odds ratio, 8.9, 95% confidence interval, 2.2–36.3). A total of 285 (95%) of 301 serogroup W135 isolates were identified as 1 clone by pulsed-field gel electrophoresis; 7 representative strains belonged to the ST-11/ET-37 complex. Conclusions.Serogroup W135 has become endemic in Gauteng, South Africa, causing disease of greater severity than did the previous predominant serogroup A strain.

Outbreaks of meningococcal meningitis (meningitis caused by Neisseria meningitidis) are a major public health concern in the African \"meningitis belt,\" which includes 21 countries from Senegal to Ethiopia. Of the several species that can cause meningitis, N. meningitidis is the most important cause of epidemics in this region. In choosing the appropriate vaccine, accurate N. meningitidis serogroup determination is key. To this end, we developed and evaluated two duplex rapid diagnostic tests (RDTs) for detecting N. meningitidis polysaccharide (PS) antigens of several important serogroups. Mouse monoclonal IgG antibodies against N. meningitidis PS A, W135/Y, Y, and C were used to develop two immunochromatography duplex RDTs, RDT1 (to detect serogroups A and W135/Y) and RDT2 (to detect serogroups C and Y). Standards for Reporting of Diagnostic Accuracy criteria were used to determine diagnostic accuracy of RDTs on reference strains and cerebrospinal fluid (CSF) samples using culture and PCR, respectively, as reference tests. The cutoffs were 10(5) cfu/ml for reference strains and 1 ng/ml for PS. Sensitivities and specificities were 100% for reference strains, and 93.8%-100% for CSF serogroups A, W135, and Y in CSF. For CSF serogroup A, the positive and negative likelihood ratios (+/- 95% confidence intervals [CIs]) were 31.867 (16.1-63.1) and 0.065 (0.04-0.104), respectively, and the diagnostic odds ratio (+/- 95% CI) was 492.9 (207.2-1,172.5). For CSF serogroups W135 and Y, the positive likelihood ratio was 159.6 (51.7-493.3) Both RDTs were equally reliable at 25 degrees C and 45 degrees C. These RDTs are important new bedside diagnostic tools for surveillance of meningococcus serogroups A and W135, the two serogroups that are responsible for major epidemics in Africa.

Background. During the period 2001–2002, Burkina Faso reported its first meningitis epidemic due to Neisseria meningitidis (Nm) serogroup W135, prompting concerns that this serogroup would persist as a cause of epidemic disease. Methods. During the period 2002–2005, hospital- and population-based surveillances were conducted in 3 districts in Burkina Faso. Etiology was determined by culture, polymerase chain reaction (PCR), and latex agglutination. Reference laboratories determined phenotype and genotype. Results. of 2004 subjects who received a lumbar puncture, 265 were identified as having Nm, including 93 who had Nm serogroup A (NmA) and 146 who had Nm serogroup W135 (NmW135). Over the study period, the proportion of cases due to NmW135 decreased by >75%, primarily because of decreased occurrence among young children and in a single district. During peak epidemic months, the annualized incidence of NmW135 decreased from 146 cases to <1 case per 100,000 population. All but 2 NmW135 isolates were phenotype W135:2a:P1.5,2 (sequence type [ST]-11 clonal complex). All NmA isolates were phenotype A:4:P1–9 (ST-2859 of the ST-5 clonal complex). We identified 1 isolate from serogroup Y (ST-11 clonal complex), 1 isolate from serogroup X that was similar to strains previously associated with epidemic disease, and 1 isolate from serogroup W135 of the newly described ST-4375 complex. Conclusions. For unknown reasons, serogroup W135 achieved epidemic status, primarily among young children, and then largely disappeared over a short time period. The continued circulation of multiple strains with epidemic potential emphasizes the need for ongoing surveillance and the potential benefit of vaccines that are protective across serogroups.

In 2001 a significant proportion of cases of meningococcal meningitis toward the end of a serogroup A epidemic in Niger and Burkina Faso was found to be caused by serogroup W135 meningococci. The World Health Organization put in place in several African countries an extended surveillance scheme in preparation for a possible epidemic situation. In January 2002, the first large epidemic of meningococcal disease caused by serogroup W135 started in Burkina Faso, resulting in more than 12,000 cases and 1400 deaths. We report here the results of the laboratory-based surveillance and the characteristics of the epidemic clone.

Analysis of meningococcal strains recovered from outbreaks and epidemics in the African meningitis belt, using molecular methods, has demonstrated for nearly 20 years the dominance among serogroup A organisms of a single clone complex, the sequence type 5 (ST-5) complex. However, a shift was observed since the mid-1990s when ST-5 gradually was replaced by ST-7 in all countries of the region. Since 2001, outbreaks caused by serogroup W135 strains belonging to the ST-11 complex became an additional problem. Monitoring of the clones responsible for meningococcal disease provides important insights on the biology and epidemiology of this most serious pathogen.

Invasive meningococcal disease due to serogroups A, C, Y and W-135 is a serious, vaccine-preventable, worldwide public-health problem. Despite early treatment and advances in medical care, morbidity and mortality rates have essentially remained unchanged. Monovalent, meningococcal serogroup C conjugate (MCC) vaccines against Neisseria meningitidis are effective in children under 2 years of age. MCC vaccines also provide indirect protection to unvaccinated individuals through herd immunity by reducing nasopharyngeal carriage in immunized individuals. Evidence from MCC and other conjugate vaccine initiatives supports immunization initiated as a late infancy/toddler program for prevention of disease caused by serogroups C, Y and W-135. We propose that a meningococcal vaccination program focused on later infancy and the early second year of life should be the preferred approach, providing comparable effectiveness to an early-infant strategy with fewer overall doses and greater cost-effectiveness.

Burkina Faso lies within the African meningitis belt. Until recently, serogroup A of Neisseria meningitidis was the most common cause of epidemic meningitis in Burkina Faso. However, during the epidemic that started in January 2002, W135 was the predominant serogroup of meningococcus. Vaccine against the W135 serogroup is expensive and in short supply. Strategies to react to a future African epidemic of W135 meningococcal meningitis with a sufficient and affordable supply of vaccine must be put into place now.

Acute epiglottitis is a severe and potentially life-threatening condition. Since the implementation of Haemophilus influenzae vaccination, the number of cases of epiglottitis has decreased and the proportion of other infectious causes has increased. We report a case of acute epiglottitis in a teenager caused by Neisseria meningitidis, an unusual pathogen.