Meningococcal disease: changes in epidemiology and prevention

Abstract

The human bacterial pathogen Neisseria meningitidis remains a serious worldwide health threat, but progress is being made toward the control of meningococcal infections. This review summarizes current knowledge of the global epidemiology and the pathophysiology of meningococcal disease, as well as recent advances in prevention by new vaccines. Meningococcal disease patterns and incidence can vary dramatically, both geographically and over time in populations, influenced by differences in invasive meningococcal capsular serogroups and specific genotypes designated as ST clonal complexes. Serogroup A (ST-5, ST-7), B (ST-41/44, ST-32, ST-18, ST-269, ST-8, ST-35), C (ST-11), Y (ST-23, ST-167), W-135 (ST-11) and X (ST-181) meningococci currently cause almost all invasive disease. Serogroups B, C, and Y are responsible for the majority of cases in Europe, the Americas, and Oceania; serogroup A has been associated with the highest incidence (up to 1000 per 100,000 cases) and large outbreaks of meningococcal disease in sub-Saharan Africa and previously Asia; and serogroups W-135 and X have emerged to cause major disease outbreaks in sub-Saharan Africa. Significant declines in meningococcal disease have occurred in the last decade in many developed countries. In part, the decline is related to the introduction of new meningococcal vaccines. Serogroup C polysaccharide-protein conjugate vaccines were introduced over a decade ago, first in the UK in a mass vaccination campaign, and are now widely used; multivalent meningococcal conjugate vaccines containing serogroups A, C, W-135, and/or Y were first used for adolescents in the US in 2005 and have now expanded indications for infants and young children, and a new serogroup A conjugate vaccine has recently been introduced in sub-Saharan Africa. The effectiveness of these conjugate vaccines has been enhanced by the prevention of person-to-person transmission and herd immunity. In addition, progress has been made in serogroup B-specific vaccines based on conserved proteins and outer membrane vesicles. However, continued global surveillance is essential in understanding and predicting the dynamic changes in the epidemiology and biological basis of meningococcal disease and to influence the recommendations for current and future vaccines or other prevention strategies.

Meningococcal B vaccination: real-world experience and future perspectives

“…In 2006, with the extensive use and implementation of the MenC conjugate vaccine, the epidemiological situation changed again, making MenB the principal agent of meningitis and septicemia, mainly affecting children in the first months of life and adolescents. 1,20 The molecular epidemiology studies have confirmed that several hundred PorA genotypes have been identified among capsular group B isolates worldwide. Anyway, even if the disease is caused by relatively few PorA subtypes, the development of a PorA based vaccine against MenB has been hampered by the requirement to obtain a broad protection against heterologous strains (PorA subtypes).…”

[Meningococcal meningitis: a case of serogroup W in an underage migrant]

“…Per quanto concerne la sintomatologia va sottolineato che, trattandosi di un bambino, a volte i sintomi classici possono non essere presenti o comparire in maniera atipica: infatti la temperatura corporea ha manifestato, durante l'osservazione ospedaliera, solo tre accessi (in due giornate) su un andamento pressoché costantemente afebbrile, prevalendo così, nel nostro caso, la sintomatologia da irritazione meningea. Dal punto di vista epidemiologico il sierogruppo W riscontrato ci permette di focalizzare l'attenzione su un dato fondamentale: la variabilità delle caratteristiche sierotipiche e dell'incidenza della malattia da meningococco, sia geograficamente sia nel corso del tempo [7]. Infatti, sia in Europa sia, in scala più ampia, a livello mondiale, emergono casi singoli o focolai attribuibili a sierogruppi diversi da quelli endemici, considerati propri di una determinata area geografica.…”

“…Qui la malattia è endemica e l'80-85% dei casi riscontrati sono da attribuire al meningococco di sierogruppo A [5], anche se ultimamente vengono segnalate variazioni di tendenza [7].…”

“…Considerando i sierogruppi capsulari e specifici genotipi denominati complessi clonali ST, attualmente la maggior parte delle malattie invasive sono causate da: [7]. cremento dei casi di meningococco C della Toscana del 2015 [2].…”

Multiple Functions of Glutamate Uptake via Meningococcal GltT-GltM l -Glutamate ABC Transporter in Neisseria meningitidis Internalization into Human Brain Microvascular Endothelial Cells

“…It usually exists in an asymptomatic nasopharyngeal carriage state at a rate of 0.4% to 25% in human populations (1,2). However, N. meningitidis can cause devastating invasive diseases, such as septicemia or meningitis, by penetration of the mucosal tissue, invasion of the bloodstream, and colonization of the meninges.…”