Epidemiological and Molecular Characterization of Invasive Meningococcal Disease in Italy, 2008/09-2012/13

Abstract

BackgroundFollowing the introduction of meningococcal serogroup C conjugate vaccine in Italy in 2005, changes in the epidemiology of Invasive Meningococcal Disease (IMD) were expected. The study aims were to describe the epidemiological trend and to characterize the isolates collected during the period 2008/09-2012/13 by multilocus sequence typing (MLST). Data on laboratory confirmed meningococcal diseases from National Surveillance System of IMD were reported.MethodsPoisson regression models were used to estimate the incidence rate over time. Serogrouping and MLST were performed following published methods.ResultsThe incidence rate of laboratory confirmed meningococcal disease decreased from 0.33 per 100,000 population in 2008/09 to 0.25 per 100,000 population in 2012/13. The serogroup B incidence rate was significantly higher (p<0.01) than that of other serogroups, among all age groups. The significant decrease of the IMD incidence rate (p = 0.01) reflects the decrease of serogroup B and C, in particular among individuals aged 15–24 years old (p<0.01). On the other hand, serogroup Y incidence increased during the period (from 0.01/100,000 in 2008/09 to 0.02/100,000 in 2012/13, p = 0.05). Molecular characterizations revealed that ST–41/44 cc and ST–11 cc were the main clonal complexes identified among serogroup B and C isolates, respectively. In particular, ST–41/44 cc was predominant in all age groups, whereas ST–11 cc was not identified in infants less than 1 year of age.ConclusionsIMD incidence declined in Italy and serogroup B caused most of the IMD cases, with infants having the highest risk of disease. Continued surveillance is needed to provide information concerning further changes in circulating meningococci with special regard to serogroup distribution. Moreover, knowledge of meningococcal genotypes is essential to detect hyper-invasive strains.

Invasive meningococcal disease in the Veneto region of Italy: a capture-recapture analysis for assessing the effectiveness of an integrated surveillance system

“…An accurate serotyping achieved by involving microbiologists allows calculating the CFR for singular meningococcal serogroups. [30][31][32] When MenB was considered alone in our analysis, the CFR was 16.4%, a figure similar to the one reported in the Italian paediatric population. 21 It is impossible to say whether any patients with IMD died before reaching hospital.…”

Systematic literature review of the impact and effectiveness of monovalent meningococcal C conjugated vaccines when used in routine immunization programs

“…A total of 30 studies reported impact of MCCV vaccination programs and 17 studies reported vaccine effectiveness (direct effect) of MCCV. Studies came from 9 different countries; 11 from England and Wales/UK [20][21][22][23][24][25][26][27][28][29][30], 10 from Spain [31][32][33][34][35][36][37][38][39][40], 5 from Canada [41][42][43][44][45], 4 each from Brazil [46][47][48][49] and Italy [50][51][52][53], 2 each from Australia [54,55] and the Netherlands [56,57], and one each from Germany [58] and Belgium [59]. The MCCV were introduced as part of the routine childhood NIP in all these countries.…”

Invasive Meningococcal Disease in Italy: from the analysis of national data to an evidence-based vaccination strategy.

“…Nevertheless, the overall number of cases caused by non-B serogroups, increased during the study period. In particular, an increase in cases of IMD related to serogroups Y and W was described [ 40 , 41 , 48 ], whereas serogroup C was almost s from 2012 to 2014, increasing in 2015 and 2016 [ 40 , 43-45 ]. This epidemiological evidence, as well as the possibility of capsular switch from one serogroup to another [ 12 , 18-22 ], should lead the national decision makers to boost the use of the MenACWY vaccine instead of MenC in the next PNPV, as already done in Emilia-Romagna [ 49 ], Apulia [ 50 ] and Sicily [ 51 , 52 ] and recently implemented in other countries [ 53 , 54 ], to ensure more comprehensive protection.…”