CORE Metadata, citation and similar papers at core.ac.uk Provided by Journal of Preventive Medicine and Hygiene (JPMH) J PREV MED HYG 2012; 53: 61-67 REV I EW Present situation and new perspectives for vaccination against Neisseria meningitidis in Tuscany, Central Italy A. BECHINI, M. LEVI, S. BOCCALINI, E. TISCIONE, V. CECCHERINI, C. TADDEI, E. BALOCCHINI*, P. BONANNI Department of Public Health, University of Florence, Italy; * Tuscany Regional Health Authority, Florence, Italy Key words Neisseria meningitidis • Vaccination strategies • Prevention Summary Background. In Italy one third of bacterial meningitis are caused on meningococcal conjugate vaccine use and recommendation by Neisseria meningitidis. In March 2005, the Regional Health was performed. Authority of Tuscany included the meningococcal serogroup C Results. A decrease in incidence rates of meningococcal menin- conjugate (MCC) vaccine in the recommended vaccination pro- gitis was observed in all age groups involved in the immunization gram with a schedule of three doses to all newborns at 3, 5 and 13 campaign. Immunization coverage with MCC increased progres- months of age (from 2008 amended to a single dose at 13 months) sively year by year in Tuscany. A herd immunity effect was meas- and a single catch-up dose until age 6. ured in unvaccinated age groups. Since 2006 no cases of invasive Objective. To evaluate the impact of the current national and meningococcal C infection in vaccinated subjects were observed regional immunization strategies against N. meningitidis and to in Tuscany. highlight new perspectives for meningococcal disease prevention Conclusions. Implementation of MCC vaccination in Tuscany with the existing tetravalent meningococcal vaccine (ACWY) and was effective in preventing meningococcal C disease, confirming with the future incoming meningococcal B vaccines. the effectiveness of the vaccine. A new tetravalent (ACWY) con- Methods. Meningitis incidence rates in Italy and in Tuscany were jugate vaccine is now available and its use in all Italian Regions calculated for the period 1994-2011 and 2005-2011,respectively. should be considered. Immunization coverage with MCC vaccine in Tuscany and vacci- nation status of meningitis cases were reported. Literature review The full article is free available on www.jpmh.org Introduction group C. The highest proportion of cases (32%) was observed in subjects 1-4 years old [7]. In 1994, 603 Meningococcal invasive disease is a life-threatening cases of bacterial meningitis were reported in Italy one infection that affects mostly children and adolescents third of which were due to N. meningitidis (33.4%) and worldwide. It is estimated that around 500,000 cases occurred in subjects below five years of age (35.7%). and 50,000 deaths occur annually worldwide [1]. The The estimated incidence of N. meningitidis in Italy case-fatality rate is 7.78% in Europe and 10-14% in the was 0.27/100,000. Serogroup B accounted for 62.5% USA, and serious sequelae, including deafness, neuro- of the serotyped isolates, group C for 23.1%, group A logical problems and amputations are possible among for 7.2%, group W-135 for 3.6%, group Y for 1.8% [8] survivors [2, 3]. During 1999-2001, the average incidence was 0.4 cases per 100,000 inhabitants. Serogroup B was predominant Historical overview of the epidemiology and accounted for 75% of the isolates, followed by se- of N. MENINGITIDIS in Italy rogroup C with 24% [9]. Before 1987 the incidence of meningococcal cases in In Italy, each year about 900 cases of bacterial menin- Italy was over 1/100,000 and has stabilized at around gitis occur, one third are caused by N. meningitidis, one 0.6/100,000 in 1987 [4]. The highest number of cases third by S. pneumoniae, while in the remaining cases ei- in 1987 was seen in the 1-4 year-old age group (27%). ther the cause is represented by different bacteria or it The highest percentage of the isolates (63%) belonged remains unknown. to serogroup C while 25% belonged to serogroup B [5]. Between 1985 and 1989 in Italy N. meningitidis sero- Available vaccines against N. MENINGITIDIS group C dominated. The incidence rate at the end of Five major groups of N. meningitidis (A, B, C, Y and the Eighties was 0.5/100,000 in the general population. W135) are responsible for most meningococcal dis- The highest proportion of cases (27%) was seen in sub- eases. Vaccination is the main tool in the fight against jects 5-14 years old. Forty-four percent of the isolates meningococcal meningitis. Infections caused by sero- belonged to serogroup B while 37% belonged to group groups A, C, Y and W135 can be prevented by poly- C [6]. In 1990 a predominance of serogroup B was re- saccharide vaccines, which however are not effective vealed (72% of the isolates) while 12% belonged to in younger children, especially under 2 years of age, 61 A. BECHINI ET AL. in whom a T-cell dependent immunity is not induced The purpose of this study was to evaluate the impact and a long-term immunological memory cannot be of the current national and regional immunization elicited. strategies against N. meningitidis and to highlight new Currently conjugate vaccines for the prevention of N. perspectives for meningococcal disease prevention meningitidis serotype C infection are available. MCC with the existing tetravalent meningococcal vaccine vaccines were developed in the late 1990s, after the suc- (ACWY) and with the future incoming meningococcal cessful experience with Haemophilus influenzae and B vaccines. pneumococcal conjugate vaccines [10]. United King- dom was the first country to introduce the vaccination in 1999 [11]. Due to the success of the immunization Methods programme, in 2000 the vaccine was also introduced into national publicly funded routine immunization Data collection programmes in Ireland and Spain; in 2002 in Iceland, Data collection started in 2009 and ended in February in Belgium and in the Netherlands; in 2006 in Portugal, 2012. The Regional Health Authority provided surveil- Greece and Germany [12]. lance data on IBD: • notification of meningitis cases by etiologic agent Vaccination strategies in Italy and Tuscany and year of notification In Italy the Ministry of Health entitles Regions and Au- • immunization coverage at 24 months of age, by birth tonomous Provinces to implement different meningococ- cohort. cal vaccination policies according to the local epidemiol- Incidence rates were calculated by age groups: < 1 year; ogy and priorities. In the Italian National Vaccine Plan 1-4 years; 5-14 years; 15-20 years; 21-30 years; 31-49 2012-2014 MCC vaccination was recommended for in- years; 50-64 years; ≥ 65 years. fants between 13 and 15 months of age and for adoles- In order to calculate incidence data for meningitis cas- cents (11-18 years) [13]. Since 2003, the MCC vaccine in es the number of notified cases in Tuscany was divid- Tuscany was offered to subjects at risk in all age groups ed by the resident Tuscan population in the same age and it was accessible to all subjects in co-payment. groups [16]. Tuscany was the first Region to approve and include the Italian surveillance data were obtained by means of the conjugate meningococcus C (MCC) vaccination in the SIMI (Infectious Diseases Information System) data- recommended vaccination program with a schedule of base and incidence rates were calculated on the resident three doses to all newborns at 3, 5 and 13 months of age Italian population [17]. (from 2008 amended to a single dose at 13 months) and The SIMI provides passive notification data; it is based a single catch-up dose until age 6 [14]. on the notifications filled by the local public health units Recently (March 2010), a quadrivalent conjugate vac- on the basis of the medical reports received. To calcu- cine against serogroups A, C, Y, W-135, was authorized late the vaccination coverage, the number of vaccinated in European Union and it is now indicated for active children (numerator) was derived from the coverage da- immunisation of children (from 2 years of age), adoles- tabase of the 12 regional local health care units, whereas cents and adults at risk of exposure to Neisseria menin- the total number of children eligible for vaccination in gitidis groups A, C, W135 and Y, to prevent invasive each age group (denominator), was obtained from the disease [15]. census data from the same areas. Fig. 1. Cases of N. meningitidis by serogroup B and C in Italy, by year (2001-2011*) (*) data for 2011 are updated to 24 February 2012. 62 VACCINATION AGAINST NESSERIA MENINGITIDIS IN ITALY Results Tab. I. Proportion of meningitis caused by serogroups C on the total of N. meningitidis isolates in Italy, by year (2991-2011*) (*) data of 2011 are provisional and updated to February 2012. Italy and Tuscany In Italy a shift in prevalence from serogroup C to se- Neisseria total Percentage of C/ meningitidis isolated (C+B+unidentified) rogroup B isolates was observed during the Nineties serogroup C meningococci and up to 2003. In the years 2004 and 2005 isolates of serogroup C have exceeded those of serogroup B 2001 22 88 25,0 (Fig. 1). 2002 46 113 40,7 The proportion of serogroup C isolates was over 50% 2003 67 157 42,7 for both 2004 and 2005 and decreased to about 20% in 2004 102 178 57,3 2011 (Tab. I). 2005 115 208 55,3 Since 2006 the annual number of N. meningitidis cases 2006 39 116 33,6 has remained under 200 ranging between 141 and 187 2007 43 124 34,7 cases corresponding to incidence values between 0.31 and 0.23 (Fig. 2) [17]. 2008 55 133 41,4 The highest incidence rates of meningitis cases due to any 2009 46 138 33,3 causal agents in Tuscany from 2005 to 2011 were cal- 2010 21 95 22,1 culated in infants, ranging from 3.2/100.000 in 2005 to * 9.3/100.000 in 2010.