Carriage ofNeisseria meningitidisin Europe: a review of studies undertaken in the region

Abstract

Meningococcal conjugate vaccines induce herd protection by preventing nasopharyngeal meningococcal acquisition, which is a prerequisite for invasive disease. Thus, meningococcal carriage epidemiology is important in understanding relationships between carriage and disease. A literature search traced information on meningococcal carriage in 27 EU countries. Meningococcal carriage prevalence differed within and between countries, varying across age groups, serogroup distribution and over time. Carriage prevalence increased during childhood, peaking in 15-24-year-olds. While serogroup B was usually the dominant serogroupable carried serogroup, serogroups C, W-135 and Y were also frequently carried. Current carriage studies in Europe are limited. New studies using standardized methods are needed to improve our understanding of meningococcal disease etiology and transmission, and to monitor the impact of meningococcal conjugate vaccines in populations.

Molecular and Serological Diversity of Neisseria meningitidis Carrier Strains Isolated from Italian Students Aged 14 to 22 Years

“…In the region of the study, vaccination coverage in infants is currently about 70%, while it is lower in teenagers (20%). This finding is consistent with the results obtained in Germinario et al (48) and with British and European data (49,50). No MenA strains were isolated.…”

Meningococcal carriage in children and young adults in the Philippines: a single group, cross-sectional study

“…For a small proportion of carriers, the serogroup could not be identified which may reflect the presence of noncapsulated isolates, or those expressing capsular serogroups other than A, B, C, W or Y. These findings are consistent with a review of carriage studies undertaken in Europe, where serogroup B was found to be the dominant serogroupable meningococcus carried [3]. Further characterization by MLST indicated that a considerable proportion of the clonal complexes identified were associated with strains causing invasive disease, with 21/31 (67·7%) clonal complexes identified reflecting those isolated from confirmed cases of invasive meningococcal disease reported through routine surveillance in the European region in 2012 [23].…”

“…carriers might be highest in this age group [2,3]. The study was also restricted to a local Filipino population recruited from Manila, so caution should be exercised when extending the findings to other Southeast Asian populations.…”

“…The highest prevalence is often found in adolescents and young adults suggesting that this age group plays a key role in transmission [2]. However, the dynamics and epidemiology of meningococcal carriage remain to be fully understood, with existing data often relatively limited [2][3][4]. Age-stratified carriage profiles may vary to some extent in different population groups due to different cultural and social demographics, which likely influence transmission patterns and risk factors for carriage acquisition [5,6].…”

The changing epidemiology of meningococcal disease in North America 1945–2010

“…4 However, although the prevalence of population carriage has been studied relatively extensively in European populations, there are comparatively few carriage data available from North America. 4,5 Neisseria meningitidis is categorized into serogroups according to the structure of the capsular polysaccharide. Five serogroups-A, B, C, Y and W-135-account for almost all the disease in the USA and Canada, although at least 13 serogroups exist worldwide.…”