Neisseria meningitidisinfection: who, when and where?

Abstract

Neisseria meningitidis is a Gram-negative β-proteobacterium responsible for an endemic worldwide infection. The epidemiology and serogroup distribution can change very quickly. The incidence of meningitis infection varies from very rare to more than 1000 cases per 100,000 of the population yearly. The carriage of N. meningitidis, which represents an exclusive human commensal, is asymptomatic, but in rare cases bacteria proliferate in the CNS and rapidly lead to the death of the affected subjects. Host genetic factors, such as single nucleotide polymorphisms, can promote meningococcal disease, being able to influence the individual predisposition to the pathology. Although a reduction in meningococcal disease has been observed in Europe, a continuous surveillance is necessary to control any possible outbreaks of new hypervirulent clones into populations that could modify the epidemiology of meningococcal infections and the clinical spectrum of affected subjects.

Human genetics of meningococcal infections

“…Future genetic studies may focus on meningococcal strainspecificity, elaborate on disease-outcome specific associations, and include a better understanding of the effect size(s) contributed by a single or combination of variants/mutations in IMD which can help in estimating clinical risk of developing IMD at the individual level. In the UK, the recent introduction of the 4CMenB vaccine has reduced but not eliminated IMD (Parikh et al 2016); however, the efficacy in protecting those with underlying immunodeficiencies remains unknown (Gianchecchi et al 2015). The most vulnerable patients who develop IMD may contribute to vaccine failures due to the nature of their immunodeficiencies as observed in invasive pneumococcal disease (Maglione et al 2014).…”

Meningococcal Vaccinations

“…Meningococcal disease occurs worldwide with epidemiologic trends and causative N. meningitidis serogroups/sequence types (ST) varying widely by geographic location (Fig. 1 ) [ 1 , 17 ]. Serogroups of N. meningitidis are based on the polysaccharide capsular structure, with six (A, B, C, W, X and Y) of the 12 known serogroups (A, B, C, E, H, I, K, L, W, X, Y and Z) causing the majority of disease [ 1 , 18 – 20 ].…”

“…Serogroup B predominates in Australia and New Zealand with a notable reduction in serogroup C post introduction of meningococcal C conjugate vaccine in Australia, whereas the incidence of serogroup C has remained unchanged in New Zealand with approximately 10–30 cases per year during the past 10 years [ 22 ]. Serogroups A, B and C predominate in Russia; and based on limited data, serogroups A and C in Asia with serogroup B responsible for sporadic cases in China [ 17 , 23 ]. Serogroups B and Y cause the majority of meningococcal disease cases in Japan, even though the incidence is very low with an estimated <30 cases per year [ 17 ].…”

Vaccinations for Neuroinfectious Disease: A Global Health Priority

“…Meningococcal disease is caused by certain serogroups of the Gram-negative proteobacteria Neisseria meningitides [63]. Sporadic cases are found worldwide, with large outbreaks occurring in the Bmeningitis belt^of sub-Saharan Africa, often during the November to June dry season.…”

“…Though N. meningitides is a human commensal, in rare cases it can proliferate in the CNS, with infection resulting in meningitis or meningoencephalitis, which is fatal in 5-10 % cases [11]. Permanent neurologic sequelae are common among survivors [63].…”