Serogroup C meningococci in Italy in the era of conjugate menC vaccination.

BACKGROUND: To assess changes in the pattern of Invasive Meningococcal Disease (IMD) in Italy after the introduction of conjugate menC vaccine in the National Vaccine Plan 2005-2007 and to provide information for developing timely and appropriate public health interventions, analyses of microbiological features of isolates and clinical characteristics of patients have been carried out. In Italy, the number of serogroup C meningococci fell progressively following the introduction of the MenC conjugate vaccine, recommended by the Italian Ministry of Health but implemented according to different regional strategies. METHODS: IMD cases from January 2005 through July 2008 reported to the National Meningococcal Surveillance System were considered for this study. Serogrouping and sero/subtyping were performed on 179 serogroup C strains received at the National Reference Laboratory of the Istituto Superiore di Sanità. Antibiotic susceptibility testing was possible for 157 isolates. MLST (Multilocus sequence typing), porA VRs (Variable Region) typing, PFGE (Pulsed Field Gel Electrophoresis), VNTR (Variable Number Tandem Repeats) analyses were performed on all C:2a and C:2b meningococci (n = 147), following standard procedures. RESULTS: In 2005 and 2008, IMD showed an incidence of 0.5 and 0.3 per 100,000 inhabitants, respectively. While the incidence due to serogroup B remained stable, IMD incidence due to serogroup C has decreased since 2006. In particular, the decrease was significant among infants. C:2a and C:2b were the main serotypes, all C:2a strains belonged to ST-11 clonal complex and all C:2b to ST-8/A4. Clinical manifestations and outcome of infections underlined more severe disease caused by C:2a isolates. Two clusters due to C:2a/ST-11 meningococci were reported in the North of Italy in December 2007 and July 2008, respectively, with a high rate of septicaemia and fatal outcome. CONCLUSION: Public health surveillance of serogroup C invasive meningococcal disease and microbiological/molecular characterization of the isolates requires particular attention, since the hyper-invasive ST-11 predominantly affected adolescents and young adults for whom meningococcal vaccination was not recommended in the 2005-2007 National Vaccine Plan.

Health and Climate Change: science calls for global action.

Climate changes affect social and environmental health determinants such as clean air, ecosystems health, safe drinking water and safe sufficient food. Globally, people at greatest risk of adverse health effects associated with climate change include children, the elderly and other vulnerable groups. Temperature-related death and illness, extreme events, polluted or stressed ecosystems represent relevant issues raising concern for both health and economic consequences. The aim of the Symposium "Health and Climate Change" (Istituto Superiore di Sanità, Rome 3-5 December 2018) was to promote an inter-sectoral and multidisciplinary approach to estimate and prevent climate change-related events as well as to call the authorities to put in place measures to reduce adverse health effects. At the end of the Symposium the Rome International Charter on Health and Climate Change was presented. It includes a series of actions and recommendations, discussed and shared by all the participants, intended to inform policy makers and all the stakeholders involved in the management of climate changes.

Characterization of invasive serogroup Y meningococci in Italy: prevalence of ST-23 Complex/Cluster A3.

The percentage of Neisseria meningitidis serogroup Y isolated from patients with invasive meningococcal disease (IMD) in Italy has increased from 1998 to 2006. In this study, phenotypic features and genetic relatedness have been investigated in all serogroup Y meningococci isolated during that period. Multilocus sequence typing (MLST) identified the ST-23 complex/Cluster A3 as the major clonal complex in 88.8% of the strains. That complex included all strains belonging to the sequence type (ST) 23 isolated from 1998 to 2004, whereas the ST-3171 was prevalent among strains in the years 2005 and 2006. The STs 23 and 3171 differ for only one nucleotide in the phosphoglucomutase (pgm) housekeeping gene. Over 80% of serogroup Y ST-23 complex/Cluster A3 strains showed phenotype Y:14:NST and 85% of the latter resulted indistinguishable by pulsed-field gel electrophoresis analysis. In 2005, serogroup Y meningococci with decreased susceptibility to penicillin were isolated for the first time in Italy. In the following year, three of the seven strains showed this phenotype. The results of this study allow us to draw a profile of the molecular characteristics of invasive serogroup Y in Italy and will be helpful to monitor the spread of this serogroup in the next years.

Genetic diversity of invasive strains of Haemophilus influenzae type b before and after introduction of the conjugate vaccine in Italy.

We determined the genotypes of 95 invasive Haemophilus influenzae type b (Hib) strains collected before and after introduction of widespread Hib vaccination in Italy. No substantial change in genetic diversity was highlighted by pulsed-field gel electrophoresis. However, an upward temporal trend in proportion of strains possessing multiple copies of the capsulation b locus was detected (P = .03).

Serotype distribution, antibiotic susceptibility, and genetic relatedness of Neisseria meningitidis strains recently isolated in Italy.

The availability of new polysaccharide-protein conjugate vaccines against Neisseria meningitidis serogroup C prompted European National Health authorities to carefully monitor isolate characteristics. In Italy, during 1999-2001, the average incidence was 0.4 cases per 100,000 inhabitants. Serogroup B was predominant and accounted for 75% of the isolates, followed by serogroup C with 24%. Serogroup C was isolated almost twice as frequently in cases of septicemia than in cases of meningitis, and the most common phenotypes were C:2a:P1.5 and C:2b:P1.5. Among serogroup B meningococci, the trend of predominant phenotypes has changed from year to year, with a recent increase in the frequency of B:15:P1.4. Only a few meningococci had decreased susceptibility to penicillin, and, in the penA gene, all of these strains had exogenous DNA blocks deriving from the DNA of commensal Neisseria flavescens, Neisseria cinerea, and Neisseria perflava/sicca. Fluorescent amplified fragment-length polymorphism analysis revealed the nonclonal nature of the strains with decreased susceptibility to penicillin.

Presence of multiple copies of the capsulation b locus in invasive Haemophilus influenzae type b (Hib) strains isolated from children with Hib conjugate vaccine failure.

Most invasive Haemophilus influenzae type b strains possess a duplication of the capsulation locus. Further amplification resulting in as many as 5 copies has been described. To verify whether amplification is involved in vaccine failure, the number of copies of the locus was determined by Southern blotting in 90 strains from children with true vaccine failure (TVF) between 1993 and 1999 and in 139 strains from unvaccinated children (50 collected between 1993 and 1999 and 89 collected between 1991 and 1992, before routine immunization was introduced). A significantly greater proportion of strains from TVFs contained multiple copies, compared with strains from control children (24% vs. 10%; P = .0379), which suggests that amplification of the capb locus may be a contributory factor in vaccine failure. The presence of multiple-copy strains was associated with disease other than meningitis.

First report of capsule replacement among electrophoretic type 37 Neisseria meningitidis strains in Italy.

This report describes the C-to-B capsular switching in four Neisseria meningitidis strains belonging to the electrophoretic type 37 (ET-37) complex. In particular, one strain belonged to the new sequence type 1860, which was first detected in the year 2000 in Italy and is now frequently isolated. The presence of switched serogroup B strains deserves special attention if they prove as able to spread as their serogroup C progenitors belonging to the hypervirulent ET-37 complex.

Emergence in Italy of a Neisseria meningitidis clone with decreased susceptibility to penicillin.

A rise in invasive diseases due to Neisseria meningitidis C:2b:P1.5 with decreased penicillin susceptibility occurred in Italy during the last 2 years. Real-time PCR identified the Peni phenotype, and the penA sequence revealed the mosaicism of the gene. Molecular analyses assigned the isolates to a single emergent clone of the hypervirulent A4 cluster.