Control of Meningococcal Meningitis Outbreaks in Sub-Saharan Africa

Outbreaks of Neisseria meningitidis recur frequently in the African Sahel where they are responsible for high mortality and morbidity; especially in children. An effective vaccine has been in existence for more than 30 years; but despite this; the control of epidemics has failed. Moreover; the geographical distribution of N. meningitidis seems to be increasing; perhaps because of climate change but also because of the economic crisis which prevails throughout much of Africa leading to population movements and the breakdown of essential services. Although alarming; the emergence of new serogroups in recent epidemics (such as serogroups X and W135) should not mask the fact that serogroup A remains the most common meningococcal isolate from meningitis cases and is therefore the most significant target for control. The development of a low-cost conjugate meningococcal vaccine should support a strategy of preventive immunization; as this strategy is one that appears most effective to control this plague

Control of Meningococcal Meningitis Outbreaks in Sub-Saharan Africa

Outbreaks of Neisseria meningitidis recur frequently in the African Sahel where they are responsible for high mortality and morbidity; especially in children. An effective vaccine has been in existence for more than 30 years; but despite this; the control of epidemics has failed. Moreover; the geographical distribution of N. meningitidis seems to be increasing; perhaps because of climate change but also because of the economic crisis which prevails throughout much of Africa leading to population movements and the breakdown of essential services. Although alarming; the emergence of new serogroups in recent epidemics (such as serogroups X and W135) should not mask the fact that serogroup A remains the most common meningococcal isolate from meningitis cases and is therefore the most significant target for control. The development of a low-cost conjugate meningococcal vaccine should support a strategy of preventive immunization; as this strategy is one that appears most effective to control this plague

A study of Physico-Chemical Interactions between Haemophilus Influenzae Type b and Meningococcus group C Conjugate Vaccines

Background: Haemophilus influenzae type b (Hib) and Meningococcal group C (MenC) conjugate vaccines; which protect against otitis media; bacteremia and invasive diseases; including pneumonia and meningitis; are attractive candidates for combination; since they are both administered to infants and children.A Hib-MenC combination booster at 12 mo has recently been introduced in the U.K. Objectives: To rule out the possibility for the individual vaccine components in a Hib-MenC combination to interact; rendering one or both of them less effective; this work assessed whether these two saccharide-protein conjugates; namely; Hib oligosaccharideCRM197 (Cross-Reacting Material 197) and MenC-CRM197; interact in solution. Furthermore an evaluation of the size and integrity of the vaccines was also performed. Methods: HPLC Size-exclusion chromatography (SEC) with UV-adsorption and refractive index detection was performed with a phosphate and non-phosphate saline buffer to characterize the size of Hib and MenC conjugates as individual components or when combined. Results: Hib-CRM197 eluted significantly earlier than MenC-CRM197 in both phosphate-saline and MOPS-saline buffers on a TSK5000 PWXL column.When combined; there was no significant change in their elution. Refractive index monitoring showed no evidence of significant free saccharide or free protein. Conclusions: By size-exclusion chromatography and refractive index detection methods; there was no indication of degradation; and no evidence of significant associative interactions between Hib-CRM197 and MenC-CRM197 in saline-based buffers; pH 7.2

Meningites a meningocoque du serogroupe W135 : etude de 148 cas observes au Burkina-Faso

L'objectif de ce travail etait d'etudier les aspects bacteriologique; clinique et evolutif de la meningite a meningocoque du serogroupe W135 observee au cours des epidemies de meningites qui ont frappe le Burkina Faso en 2002 et en 2003 a trave rs l'etude de 148 cas identifies grace a l'examen bacteri o l ogique du LCR. Les meningites a meningocoque W135 ont ete observ e e s tout au long de l'annee; avec un maximum de cas autour de la 14e semaine. Il ap p a rait une legere predominance masculine (56;1) et les jeunes de un a 15 ans ont ete les plus touches avec 81;7des cas. Le delai moyen d'hospitalisation a ete 2;6 jours et la duree moyenne d'hospita- lisation de 5;5 jours. Les signes cliniques les plus frequents ont ete la fievre (98;6); la raideur de la nuque (90;5); les signes de Brudzinski (85;1); les signes de Kernig (66;2); les tro u bles de la conscience (41;9); les vomissements (36;5) et les cephalees (34;5). Dans la majorite des cas; le traitement curatif a ete fait par administra- tion de chloramphenicol huileux en dose unique. La letalite globale qui a ete de 15;5ne semble influencee ni par le sexe ni par l'age. Sur les 23 cas de deces; 17 sont surve nus dans les 24 heures qui ont suivi l'hospitalisation des patients; cinq le deuxieme jour et un dernier le 5eme jour. Les signes cliniques constamment associes a un mauvais pronostic ont ete les troubles de la conscience; les etats de choc et les convulsions. Il apparait une association letalite/delai d'hospitalisation en effet; plus tot le patient est pris en charge plus ses chances de survie sont importantes. L'etude de la sensibilite de 102 souches a montre la grande sensibilite des meningocoques W135 a la penicilline G; a l'ampicilline; a la ceftriaxone et au ch l o ramphenicol et leur resistance aux sulfamides. En defi n i t ive; le meningocoque W135 semble peu diff e rent du meningocoque A sur les plans cl i n i q u e; epidemiologique et bacteri o l ogique d'ou la necessite de continuer a maintenir des actions de sensibilisation pour une prise en charge rapide des cas

Polymerase Chain Reaction Assay and Bacterial Meningitis Surveillance in Remote Areas; Niger

To 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

Clonal Expansion of Sequence Type (ST-)5 and Emergence of ST-7 in Serogroup A Meningococci; Africa

One hundred four serogroup A meningococci in our collection; isolated in Africa from 1988 to 1999; were characterized by multilocus sequence typing (MLST). Our results and data from the Internet indicate that sequence type 5 (ST-5) strains were responsible for most of African outbreaks and sporadic cases during this period. In 1995; a new clone; characterized by ST-7 sequence; emerged and was responsible for severe outbreaks in Chad (1998) and Sudan (1999). MLST and epidemiologic data indicate that ST-5 and ST-7 represent two virulent clones. These two STs; which belong to subgroup III; differ only in the pgm locus: allele pgm3 is characteristic for ST-5 and allele pgm19 for ST-7. Subgroup III strains were responsible for two pandemics in the 1960s and 1980s. Our data show that the third subgroup III pandemic has now reached Africa