Incidence of vaccine preventable pneumococcal invasive infections and blood culture practices in Italy

Burden of pneumococcal disease among adults in Southern Europe (Spain, Portugal, Italy, and Greece): a systematic review and meta-analysis

The aim was to summarize pneumococcal disease burden data among adults in Southern Europe and the potential impact of vaccines on epidemiology. Of 4779 identified studies, 272 were selected. Invasive pneumococcal disease (IPD) incidence was 15.08 (95% CI 11.01-20.65) in Spain versus 2.56 (95% CI 1.54-4.24) per 100,000 population in Italy. Pneumococcal pneumonia incidence was 19.59 (95% CI 10.74-35.74) in Spain versus 2.19 (95% CI 1.36-3.54) per 100,000 population in Italy. Analysis of IPD incidence in Spain comparing pre-and post- PCV7 and PCV13 periods unveiled a declining trend in vaccine-type IPD incidence (larger and statistically significant for the elderly), suggesting indirect effects of childhood vaccination programme. Data from Portugal, Greece and, to a lesser extent, Italy were sparse, thus improved surveillance is needed. Pneumococcal vaccination uptake, particularly among the elderly and adults with chronic and immunosuppressing conditions, should be improved, including shift to a higher-valency pneumococcal conjugate vaccine when available.

Impact of vaccination on invasive pneumococcal disease in Italy 2007-2017: surveillance challenges and epidemiological changes

Surveillance of new cases of invasive pneumococcal disease (IPD) in Italy was started in 2007 by the Ministry of Health (MoH). In 2012, pneumococcal childhood vaccination was introduced at the national level and, in 2017, for citizens aged 65 years and over. We describe here IPD epidemiology in Italy over the past 10 years investigating the impact of the vaccine programme on disease burden. Reports of IPD cases, data on serotype and vaccination coverage (VC) data were obtained from MoH annual reports, for the period 2007-2017. IPD notification rate and proportion by year, region, age and serotype were calculated. In 2007, 525 cases were reported (rate 0.88/100 000), rising to 1703 cases (rate 2.82/100 000) in 2017. The distribution of IPD cases by age group over time registered the largest share among individuals aged 65 years and over. A decreasing trend in notification rate was observed among those aged 0-4 years. During the same period, the 24-month VC increased, ranging from 80.9% to 96.7% in 2017. Molecular data indicated re-emergence of PPSV23-specific serotypes and non-vaccine serotypes. We observed an increase in IPD notifications during 2007-2017, likely due to an improved surveillance system, at least in some regions, with the relative quota of IPD notifications decreasing among vaccinated children cohorts. Further strengthening of IPD surveillance system, including molecular and vaccine coverage data, would be needed to assess and inform pneumococcal vaccination strategies in Italy.

Impact of pneumococcal conjugate vaccine (PCV7 and PCV13) on pneumococcal invasive diseases in Italian children and insight into evolution of pneumococcal population structure

BACKGROUND

The use of PCV7 for children immunization was gradually implemented in the Italian regions starting from 2006 and was replaced by PCV13 in 2010-2011. In this study we aimed to assess the PCV impact on invasive pneumococcal diseases (IPD) incidence, serotype distribution and antibiotic resistance in Italian children under 5years old.

METHODS

All IPD cases in children from 5 Italian regions (Emilia-Romagna, Lombardia, A. P. Bolzano, A. P. Trento, and Piemonte) reported through the nationwide surveillance system during 2008-2014 were included in this study. Pneumococcal isolates were subjected to serotyping, antibiotic susceptibility testing, and clonal analysis according to standard methods.

RESULTS

During the study period overall IPD incidence decreased from 7.8 cases/100,000 inhabitants in 2008 to 3.0 cases/100,000 in 2014 (61% decrease, P<0.001). In particular, from 2008 to 2014, PCV7-type IPD decreased from 2.92 to 0.13 cases/100,000 inhabitants (95% decrease, P<0.001) while PCV13-non-PCV7 type IPD decreased from 3.2 to 0.89 cases/100,000 inhabitants (72% decrease, P=0.008). Conversely, non-vaccine serotype (NVS) IPD increased overtime, becoming more common than PCV13 serotype IPD in 2013-2014. Emergent NVS 24F and 12F were the most prevalent in 2014. Antibiotic resistance testing revealed an overall increasing trend in penicillin resistance, from 14% in 2008 to 23% in 2014. Erythromycin resistance showed a downward trend, from 38% in 2008 to 27% in 2014. While in 2008 PCV13 serotypes were the major responsible for antibiotic resistance, during the following years antimicrobial resistance due to NVS increased, mainly as a result of expansion of pre-existing clones.

CONCLUSIONS

Both PCVs led to a substantial decrease in vaccine-related IPD incidence in the children population. However NVS-related IPD increased, becoming the most prevalent in the last two-years period. Continuous surveillance is an essential tool to monitor evolution of pneumococcal population causing IPD in children.

Serotypes not Included in 13-Valent Pneumococcal Vaccine as Causes of Acute Otitis Media with Spontaneous Tympanic Membrane Perforation in a Geographic Area with High Vaccination Coverage

In 177 children living in an area with high 13-valent pneumococcal conjugate vaccine 13 coverage, who had acute otitis media complicated with spontaneous tympanic membrane perforation, Streptococcus pneumoniae was identified in the middle ear fluid of 48 (27.1%) subjects, with 37 (77.1%) cases caused by nonpneumococcal conjugate vaccine 13 serotypes.

The burden of bacteremia and invasive diseases in children aged less than five years with fever in Italy

Background

Invasive diseases (ID) caused by Streptococcus pneumoniae (S. pneumoniae), Haemophilus influenzae (H. influenzae), and Neisseria meningitidis are a major public health problem worldwide. Comprehensive data on the burden of bacteremia and ID in Italy, including data based on molecular techniques, are needed.

Methods

We conducted a prospective, multi-centre, hospital-based study (GSK study identifier: 111334) to assess the burden of bacteremia and ID among children less than five years old with a fever of 39 °C or greater. Study participation involved a single medical examination, collection of blood for polymerase chain reaction (PCR) and blood culture, and collection of an oropharyngeal swab for colonization analysis by PCR.

Results

Between May 2008 and June 2009, 4536 patients were screened, 944 were selected and 920 were enrolled in the study. There were 225 clinical diagnoses of ID, 9.8 % (22) of which were bacteremic. A diagnosis of sepsis was made for 38 cases, 5.3 % (2) of which were bacteremic. Among the 629 non-ID diagnoses, 1.6 % (10) were bacteremic. Among the 34 bacteremic cases, the most common diagnoses were community-acquired pneumonia (15/34), pleural effusion (4/34) and meningitis (4/34). S. pneumoniae was the most frequently detected bacteria among bacteremic cases (29/34) followed by H. influenzae (3/34). Ninety percent (27/30) of bacteremic patients with oropharyngeal swab results were colonized with the studied bacterial pathogens compared to 46.1 % (402/872) of non-bacteremic cases (p < 0.001). PCV7 (7-valent pneumococcal conjugate vaccine) vaccination was reported for 55.9 % (19/34) of bacteremic cases. S. pneumoniae serotypes were non-vaccine serotypes in children who had been vaccinated. Mean duration of hospitalization was longer for bacteremic cases versus non-bacteremic cases (13.6 versus 5.8 days).

Conclusions

These results confirm that S. pneumoniae is one of the pathogens frequently responsible for invasive disease.

A retrospective analysis of hospital discharge records for S. pneumoniae diseases in the elderly population of Florence, Italy, 2010-2012

Invasive pneumococcal diseases (IPD) and community acquired pneumonia (CAP) represent two of the major causes of out-patient visits, hospital admissions and deaths in the elderly. In Tuscany (Italy), in the Local Health Unit of Florence, a project aimed at implementing an active surveillance of pneumococcal diseases in the hospitalized elderly population started in 2013. The aim of this study is to show the results of the retrospective analysis (2010-2012) on hospital discharge records (HDRs) related to diseases potentially due to S. pneumoniae, using a selection of ICD9-CM codes. All ordinary hospitalizations (primary and secondary diagnoses) of the elderly population were included (11 245 HDRs). Among a population of about 200 000 inhabitants ≥65 y, the hospitalization rate (HR) increased with increasing age and was higher in males in all age groups. Almost all hospitalizations (95%) were due to CAP, only 5% were invasive diseases. Only few cases of CAP were specified as related to S. pneumoniae, the percentage was higher in case of meningitis (100%) or septicemia (22%). In-hospital deaths over the three-year period were 1703 (case fatality rate: 15%). The risk of dying, being hospitalized for a disease potentially attributable to pneumococcus (as primary diagnosis) increased significantly with age (P < 0.001), the odds ratio (OR) per increasing age year was 1.06 (95% CI 1.05-1.07) and was higher in patients with co-existing medical conditions with respect to patients without comorbidities. Currently, an active surveillance system on S. pneumoniae diseases with the inclusion of bio-molecular tests (RT-PCR), is a key step to assess the effectiveness of the PCV13 vaccine (13-valent pneumococcal conjugate vaccine) in the elderly population after implementation of vaccination policies. The results of this study will provide the comparator baseline data for the evaluation of a possible immunization programme involving one or more cohorts of the elderly in Tuscany.

European enhanced surveillance of invasive pneumococcal disease in 2010: data from 26 European countries in the post-heptavalent conjugate vaccine era

Streptococcus pneumoniae is a leading cause of severe infectious diseases worldwide. This paper presents the results from the first European invasive pneumococcal disease (IPD) enhanced surveillance where additional and valuable data were reported and analysed. Following its authorisation in Europe in 2001 for use in children aged between two months and five years, the heptavalent pneumococcal conjugate vaccine (PCV7) was progressively introduced in the European Union (EU)/European Economic Area (EEA) countries, albeit with different schemes and policies. In mid-2010 European countries started to switch to a higher valency vaccine (PCV10/PCV13), still without a significant impact by the time of this surveillance. Therefore, this surveillance provides an overview of baseline data from the transition period between the introduction of PCV7 and the implementation of PCV10/PCV13. In 2010, 26 EU/EEA countries reported 21 565 cases of IPD to The European Surveillance System (TESSy) applying the EU 2008 case definition. Serotype was determined in 9946/21565 (46.1%) cases. The most common serotypes were 19A, 1, 7F, 3, 14, 22F, 8, 4, 12F and 19F, accounting for 5949/9946 (59.8%) of the serotyped isolates. Data on antimicrobial susceptibility testing (AST) in the form of minimum inhibitory concentrations (MIC) were submitted for penicillin 5384/21565 (25.0%), erythromycin 4031/21565 (18.7%) and cefotaxime 5252/21565 (24.4%). Non-susceptibility to erythromycin was highest at 17.6% followed by penicillin at 8.9%. PCV7 serotype coverage among children <5 years in Europe, was 19.2%; for the same age group, the serotype coverage for PCV10 and PCV13 were 46.1% and 73.1%, respectively. In the era of pneumococcal conjugate vaccines, the monitoring of changing trends in antimicrobial resistance and serotype distribution are essential in assessing the impact of vaccines and antibiotic use control programmes across European countries.

Hospitalization rates of complicated pneumococcal community-acquired pneumonia is increasing in Tuscan children

To provide epidemiological data on community-acquired pneumonia (CAP) and complicated CAP, a retrospective study was conducted on a partially vaccinated paediatric population. Data from children hospitalized for CAP in Tuscan hospitals between January 1st, 1999 and December 31st, 2009 were analysed. A total of 5,450 children with CAP were hospitalized. Annual hospitalization rates for CAP did not change significantly over the study period (X2 for trend= 0.652; p=0.419). The total annual hospitalization rate for pneumococcal CAP varied according to age (28.04 per 100,000 children aged less than 5 years, 10.06 per 100,000 children aged 6-12 years and 0.98 per 100,000 children aged greater than13years). Hospitalization rates for pneumococcal CAP increased from12.84 (95 percent CI:7.35-18.34) in 2001 to 45.4 (95 percent CI:35.93-54.90) per 100,000 children aged less than 5 years in 2009 (p less than 0.0001). In addition, a significant increase of hospitalization rates for complicated CAP (from 6.07 in 1999 to 13.66 in 2009 per 100,000 children; P less than 0.0001) and pneumococcal complicated CAP (from 0.19 in 1999 to 3.41 in 2009 per 100,000 children) over the study period were highlighted. Our epidemiological data confirm the decision to introduce the PCV13 vaccine, to satisfy the need to prevent a wider group of pneumococcal serotypes.

Socioeconomic and racial disparities of pediatric invasive pneumococcal disease after the introduction of the 7-valent pneumococcal conjugate vaccine

BACKGROUND

Racial differences have been well described for invasive pneumococcal disease (IPD), but little information exists on how race interacts with community socioeconomic factors.

METHODS

The Active Bacterial Core surveillance/Emerging Infections Program performed active surveillance for IPD in the 20-county Metropolitan Atlanta area. All IPD cases among children younger than 5 years from 2001 to 2009 were geocoded and linked to census tract-level socioeconomic measures from the 2000 US Census. Race- and socioeconomic-specific average annual incidence rates per 100,000 population were calculated. Trends in IPD incidence were determined by χ² tests for trend. Rate ratios (RRs) and 95% confidence intervals (CIs) were estimated using Poisson regression.

RESULTS

IPD incidence among the total population of children increased as percentage of household poverty increased (P = 0.002), as median household income decreased (P < 0.001), as wealth decreased (P = 0.018) and as percentage of individuals with less than a high school education increased (P = 0.023). After stratifying by race, there was no significant linear trend between socioeconomic characteristics and IPD incidence among white children; among black children, however, IPD incidence decreased as socioeconomic conditions worsened. Despite adjusting for sex and socioeconomic factors, the IPD rate remained higher among black children compared with white children (RR = 1.60; 95% CI: 1.39-1.84). Differences in RR of IPD associated with highest poverty and lowest wealth noted in 2001 [RR = 2.71 (95% CI: 2.17-3.39) and 1.80 (95% CI: 1.09-2.96), respectively] declined in 2009 [RR = 1.33 (95% CI: 0.90-1.96) and 0.76 (95% CI: 0.48-1.19), respectively].

CONCLUSIONS

Although socioeconomic disparities in IPD incidence exist among children, the association between socioeconomic characteristics and IPD rates may differ by race and may change over time. Community-level socioeconomic factors did not account for racial differences in IPD incidence.

Treatment and prevention strategies to combat pediatric pneumococcal meningitis

Pneumococcal meningitis is a severe, life-threatening infection of the nervous system affecting infants, children and adults alike. The incidence of pneumococcal meningitis in infants and children less than 2 years of age in Europe is approximately 10 out of 100,000 per year, rising to approximately 148 out of 100,000 per year in Gambian infants. The use of highly sensitive tests such as PCR may increase the likelihood of detecting the infection by 20% or more. Epidemics of serotype 1 pneumococcal meningitis in northern Ghana, have had many of the characteristics of meningococcal meningitis epidemics. Neurologic sequelae may occur in 28-63% of cases, and serotype 3 is associated with a 2.54 relative risk of death. The pathogenic process can be divided into invasion, inflammatory pathways, bacterial toxicity and damage; pneumolysin being particularly associated with apoptosis. In the future, neuroprotection may be achieved, targeting this process at all these levels. Therapeutic guidelines have been published by the Infectious Diseases Society of America. Standard empiric therapy, in those aged greater than or equal to 1 month, is a third-generation cephalosporin plus vancomycin. There is insufficient evidence relating to the use or otherwise of corticosteroids in pneumococcal meningitis to make a firm recommendation. The advent of a pneumococcal conjugate vaccine is the most powerful tool available for the prevention of pneumococcal meningitis in all parts of the world.

The status of invasive pneumococcal disease among children younger than 5 years of age in north-west Lombardy, Italy

Background

Streptococcus pneumoniae is a leading cause of invasive infection in young children causing morbidity and mortality. Active surveillance systems of invasive pneumococcal disease (IPD) are recommended worldwide. The aim of this study was to estimate the current incidence of IPD and to describe the serotype distribution and the antimocrobial susceptibility of S. pneumoniae isolates in children aged less than 5 years residing in North-West Lombardy, Italy.

Methods

A twelve-month prospective active surveillance system recruited all children aged less than 5 years admitted for suspicion of IPD at emergency room of ten hospitals located in the monitored area. Blood samples were taken in all participants for confirmation of IPD based on isolation of S. pneumoniae from blood. Pneumococcal meningitis and sepsis were additionally confirmed by cerebrospinal fluid analysis. Serotyping and antimicrobial susceptibility testing were performed on isolates from blood.

Results

A total of 15 confirmed cases of IPD were detected among 135 recruited children, including pneumonia (n = 8), bacteremia (n = 4), sepsis (n = 2) and meningitis (n = 1). The annual IPD incidence rate was 50.0/100,000 (95%CI, 30.5-82.5/100,000). Incidence was 58.3/100,000 (28.8-120.1/100,000) among children aged less than 2 years and 44.4/100,000 (22.9-87.5/100,000) among children aged 2–4 years. Thirteen isolates were typified. The most common serotype was 19A (23.1%) that together with serotypes 1, 7F and 19F accounted for 69.2% of typified isolates. Serotypes 14, 23F, 12B and 15C were also identified. The 7- and 13-valent pneumococcal conjugate vaccines covered respectively 30.8% and 84.6% of typified IPD cases. One isolate (serotype 15C) was penicillin-resistant and caused meningitis.

Conclusions

The inclusion of the 13-valent pneumococcal conjugate vaccine in immunization programs of young children might be considered to reduce incidence and morbidity of invasive pneumococcal disease in this surveilled population.

Potential serotype coverage of three pneumococcal conjugate vaccines against invasive pneumococcal infection in Italian children

BACKGROUND AND AIM OF THE WORK

Since the introduction of the 7-valent vaccine, invasive pneumococcal disease have greatly decreased; however, changes in the distribution of pneumococcal serotypes have recently highlighted the need for vaccines with wider coverage. The aim of the work was to assess the potential serotype coverage of three pneumococcal conjugate vaccines (7-, 10- and 13-valent) against bacteremic pneumococcal pneumonia and meningitis/sepsis in Italian children.

PATIENTS AND METHODS

We determined pneumococcal serotypes in immunocompetent patients who had been admitted to hospital with suspicion of invasive bacterial disease and had confirmed bacteremic pneumococcal pneumonia or meningitis/sepsis determined by molecular detection of Streptococcus pneumoniae in a normally sterile site. Positive samples were serotyped using Realtime-PCR.

RESULTS

Between April 2008 and March 2011, a total of 144 patients (age median 4.1 years; Interquartile range 1.8-5.6) with pneumococcal meningitis/sepsis (n=43) or pneumonia (n=101) from 83 participating centers located in 19 of 20 Italian regions were serotyped. The 10 most prevalent serotypes were 1 (29.9%), 3 (16.0%), 19A (13.2%), 7F (8.3%), 5 (4.2%), 14 (4.2%), 6A (3.5%), 6B (3.5%), 18C (3.5%), 19F (3.5%). Overall, serotype coverage for PCV-7, -10 and -13 were respectively 19.4%, 61.8% and 94.4% with no statistical difference between pneumonia and meningitis/sepsis. Potential coverage was similar for children 0-2 or 2-5 years of age. Cultures resulted positive in 35/99 (35.4%) samples simultaneously obtained for both culture and RT-PCR.

CONCLUSION

These findings indicate that increasing the potential serotype coverage by introducing PCV13 in the vaccination schedule for infancy could provide substantial added benefit for protection from pneumococcal pneumonia or meningitis/sepsis in Italy in children below 2 years as well in older children. The importance of molecular methods for diagnosis and serotyping of invasive pneumococcal disease was confirmed.

Impact of conjugate 7-valent vaccination in Belgium: addressing methodological challenges

In Belgium, the 7-valent pneumococcal conjugate vaccine (PCV7) was introduced into the national schedule in 2007. The early impact of PCV7 vaccination on paediatric invasive disease was estimated by comparing pre- and post-vaccination incidence from national surveillance. In children <2 year-olds, vaccine-serotype incidence declined by 96% but non-vaccine-types increased 2-3-fold. Overall invasive disease decreased by 23-46%, depending on adjustment for under-reporting and pre-vaccine trends. Non-vaccine-types 1 and 19A had increased before PCV7 use, suggesting the contribution of other factors. Estimation of PCV7 impact comparing pre- and post-vaccination data should adjust for pre-vaccine trends, and serotype dynamics need further exploration.

Eight years of active proposal of pneumococcal 23-valent polysaccharide vaccine: survey on coverage rate among elderly and chronic patients

BACKGROUND

Streptococcus pneumoniae, lancet-shaped, gram-positive, facultative anaerobic organisms, are common inhabitants of the respiratory tract and may be isolated from the nasopharynx of 5% to 70% of healthy adults.

OBJECTIVE

The aims of the study were to estimate the vaccination coverage for pneumococcal 23-valent polysaccharide vaccine and to assess the impact its introduction in the Italian region of Puglia, where a program to provide this vaccination has been operative since 2000.

METHODS

Estimation of the coverage for pneumococcal 23-valent polysaccharide vaccine was implemented by a 2-step study consisting of data collection from local health unit vaccination registers between 2000 and 2008 in Puglia and of a cluster sampling study among general practitioners to validate routine data collected during the first step. Moreover, hospitalization for invasive pneumococcal diseases was studied.

RESULTS

From 2000 to 2004, among individuals > or =65 years, the overall coverage rate estimated by routine data amounted to 26.3%; between 2005 and 2007, annual coverage rates did not exceed 8%/year. Between 2002 and 2007, the overall coverage rate estimated by interviewing general practitioners was 46.6% (95% confidence interval: 39.9-53.4). The coverage rate in chronic patients by routine data was approximately 23%, whereas the rate provided by general practitioners was 17.6% (95% confidence interval: 12.5-22.8). From 2001 to 2007, hospitalization data did not show a reduction in invasive pneumococcal disease trends among the elderly population in Puglia.

CONCLUSION

The results of this study demonstrate the need for improving vaccine coverage and implementing new immunization strategies and practices.

Surveillance of invasive pneumococcal disease in 30 EU countries: Towards a European system?

In this era of new pneumococcal conjugate vaccines (PCV), we described and compared surveillance of invasive pneumococcal disease (IPD) and PCV policies in 30 European countries to provide guidance for Europe-wide surveillance. We confirmed the heterogeneity of surveillance systems and case definitions across countries but identified elements common to all countries, such as the availability of serotyping and the surveillance of pneumococcal meningitis. PCV impact was monitored in 11/15 countries using it. We propose steps for the monitoring of incidence rates and serotype distribution at EU level, to assess the need to introduce PCV and monitor its impact once introduced.

Economic evaluation of pneumococcal conjugate vaccination in Finland

The aim of this study was to evaluate cost-effectiveness of pneumococcal conjugate vaccine (PCV7) in children <5 y of age. A Markov simulation model was used to compare the cost-effectiveness of 4 doses (assumed 50.5 euros per dose) of PCV7 with no intervention. Only direct effects of the vaccine were taken into account. In Finland, vaccination of a birth cohort of 57,500 healthy infants would potentially prevent annually 60 cases of invasive PD, 1,400 cases of pneumococcal pneumonia, 15,000 episodes of acute otitis media, 3,000 otological surgery procedures and 0.9 deaths in children aged <5 y. Investing 12.0 million euros to vaccinate a birth cohort would save annually 6.3 million euros in medical, and 2.0 million euros in productivity and other, costs. Therefore, investing 1 euros in a vaccination programme would return 0.53 euros in medical costs and 0.70 euros in societal costs. In the base case, vaccination would cost society 139,986 euros per life y gained. To achieve cost savings from a health care provider (societal) perspective, without considering herd effects or replacement phenomenon, the price of PCV7 should be 50% (70%) of the price used in the base case.

Decline in pneumonia and acute otitis media after the introduction of childhood pneumococcal vaccination in Liguria, Italy

The effect of the pneumococcal conjugate vaccine immunization programme on pneumococcal-associated or potentially pneumococcal-associated hospital admissions in the Italian region of Liguria was assessed. Hospital admission rates were compared in subjects belonging to birth cohorts before and after the introduction of widespread immunization for 0 - 2-year old children with a seven-valent conjugate vaccine (PCV7). Significant reductions in hospitalization rates for all-cause and pneumococcal pneumonia and for acute otitis media were observed in subjects born after widespread uptake of the vaccine. The preventive fraction (a measure of vaccine effectiveness) ranged from 15.2% for all cause pneumonia to 70.5% for pneumococcal pneumonia. This study contributes to the growing body of information that supports the beneficial effect of PCV7 vaccination.

Incidence of bacterial meningitis (2001-2005) in Lazio, Italy: the results of a integrated surveillance system

Background

Monitoring the incidence of bacterial meningitis is important to plan and evaluate preventive polices. The study's aim was to estimate the incidence of bacterial meningitis by aetiological agent in the period 2001–2005, in Lazio Italy (5.3 mln inhabitants).

Methods

Data collected from four sources – hospital surveillance of bacterial meningitis, laboratory information system, the mandatory infectious diseases notifications, and hospital information system – were combined into a single archive.

Results

944 cases were reported, 89% were classified as community acquired. S. pneumoniae was the most frequent aetiological agent in Lazio, followed by N. meningitis. Incidence of H. influenzae decreased during the period. 17% of the cases had an unknown aetiology and 13% unspecified bacteria. The overall incidence was 3.7/100,000. Children under 1 year were most affected (50.3/100.000), followed by 1–4 year olds (12.5/100,000). The percentage of meningitis due to aetiological agents included in the vaccine targets, not considering age, is 31%. Streptococcus spp. was the primary cause of meningitis in the first three months of life. The capture-recapture model estimated underreporting at 17.2% of the overall incidence.

Conclusion

Vaccine policies should be planned and monitored based on these results. The integrated surveillance system allowed us to observe a drop in H. influenzae b meningitis incidence consequent to the implementation of a mass vaccination of newborns.

Molecular detection methods and serotyping performed directly on clinical samples improve diagnostic sensitivity and reveal increased incidence of invasive disease by Streptococcus pneumoniae in Italian children

The aims of this study were to evaluate the incidence of invasive pneumococcal disease (IPD) in Italian children and perform serotyping by PCR-based assays directly on clinical samples. A 1-year paediatric (0-14 years) population-based surveillance study was designed to evaluate the incidence of IPD in the province of Florence, Italy, by cultural and molecular methods. Among 92 children (80 with pneumonia, 8 with meningitis/sepsis, 4 with arthritis), 4 cases of IPD were diagnosed both by culture and real-time PCR and 18 cases exclusively by molecular methods. The sensitivity of molecular methods was significantly higher than that of cultural methods (Cohen's kappa 0.41; McNemar P=0.000008). The incidence of IPD in children below 2 years of age was 11.5/100,000 and 51.8/100,000 by cultural and molecular methods, respectively. Pneumococcal serotyping by multiplex sequential PCR was obtained in 19/22 samples. Real-time PCR and multiplex sequential PCR can be used directly on biological samples, improving the ability to diagnose IPD. The incidence of IPD appears 5-10 times higher by PCR than by cultural methods.

Incidence of invasive pneumococcal disease in the Czech Republic and serotype coverage by vaccines, 1997-2006

We studied the incidence of invasive pneumococcal disease (IPD) in the Czech Republic by analysing two sources of data. The incidence of pneumococcal meningitis based on routine notification data varied between 0.4 and 0.6/100 000 population between 1997 and 2006. The incidence of IPD based on laboratory surveillance varied between 2.3 and 4.3/100 000 population between 2000 and 2006. The annual IPD incidence remained stable during the study period. Estimates of absolute IPD case-load in the entire country varied from 235 to 437 per year. The age-specific incidence was highest in the <1 year age group, reaching 4.3/100 000 for pneumococcal meningitis in routine notification and 15.7/100 000 for IPD in laboratory-based surveillance data, respectively. A total of 1236 Streptococcus pneumoniae isolates from cerebrospinal fluid and sterile body sites were investigated. The most frequent serotypes causing IPD in all ages were 3, 4, 14, 8 and 19F, accounting for 41.5% of all isolates. The most frequent serotypes by age group were: <1 year (6B and 19F); 1-4 years (14, 6B and 23F); 40-64 years (3, 8 and 4), and > or = 65 years (3, 4, 9N and 14). The coverage of serotypes in all age groups by pneumococcal vaccines ranged from 41.5% for 7-valent conjugate vaccine to 67.9% for 13-valent conjugate vaccine. The coverage of serotypes causing IPD is significantly different between infants/children and adults/elderly. PCV-7 coverage by age group was: <1 year (66.0%), 1-4 years (65.1%), 40-64 years (34.4%) and > or = 65 years (39.3%). Similar age differences between infants/children and adults/elderly were found in coverage by PCV-9, PCV-11 and PCV-13. The distribution of serotypes in the total population and individual age groups was stable during the period 2000-2006.

Epidemiologic impact of blood culture practices and antibiotic consumption on pneumococcal bacteraemia in children

This study examined the roles of two different diagnostic approaches to children with fever of unknown origin in determining the patterns of pneumococcal bacteraemia in two Spanish regions by comparing their main epidemiologic characteristics. Whereas a blood culture is routinely obtained in this setting in Navarre, this is not generally the case in Majorca. Additionally, the potential role of antibiotic consumption in each region was also analysed. Cumulative incidences in children under the age of 14 years were 26.6 per 100,000 child-years in Navarre (121.1 in children <2 years of age) and 7.3 per 100,000 child-years in Majorca (33.3 in children <2 years of age). In contrast, the incidences per 1,000 blood cultures were similar in both regions. The relative risks of occult bacteraemia, bacteraemic pneumonia and meningitis among the children of Navarre compared to Majorcan children were 11.8, 2.6 and 0.8, respectively. The risk for less virulent (vaccine serotypes plus 6A, 19A and 23A) and for more virulent serotypes (1 and 7) was 4.9 and 3.1 times higher in Navarre, respectively. The number of 7-valent pneumococcal conjugate vaccine (PCV7) doses administered between 2003 and 2004 were also higher in Navarre. Conversely, antibiotic resistance and paediatric prescriptions for broad-spectrum antibiotics were greater in Majorca. Although the most salient differences between both regions, including the effectiveness of pneumococcal conjugate vaccine in Navarre, appeared to be confounded by the higher frequency of blood cultures taken there, certain differences in serotype composition may be explained by the higher antibiotic consumption in Majorca.

Cost-effectiveness of pneumococcal vaccination for prevention of invasive pneumococcal disease in the elderly: an update for 10 Western European countries

Pneumococcal vaccine is effective in preventing invasive pneumococcal disease in adults >or=65 years of age, but it is not widely used in Western Europe. In this study, data from an earlier (1995) cost-effectiveness study on Belgium, France, Scotland, Spain, and Sweden are updated, and data on five new countries--Denmark, the UK (specifically, England and Wales), Germany, Italy and The Netherlands--are added. Epidemiological and economic variables specific for each country were used, and it was assumed that pneumococcal and influenza vaccines would both be administered during the same physician visit. In the base-case analyses, the cost-effectiveness ratios ranged from euro 9239 to euro 23,657 per quality-adjusted life-year. Because the incidence and mortality of invasive pneumococcal disease were underestimated in most countries, a country-by-country analysis was performed, assuming an incidence of 50 cases per 100,000 population and mortality rates of 20, 30 and 40%. For a mortality of 20%, the cost-effectiveness ratios ranged from euro 4,778 to euro 17,093, and for a mortality of 30%, they ranged from euro 3,186 to euro 11,395. Pneumococcal vaccination to prevent invasive pneumococcal disease in elderly adults was very cost-effective in all 10 countries. This evidence justifies the wider use of the vaccine in Western Europe.

Burden of paediatric invasive pneumococcal disease in Europe, 2005

Within the European Union (EU), documenting the burden of invasive pneumococcal disease (IPD) in infants and children is important for coordinating effective pneumococcal immunization policies. Our objective was to document the burden of IPD in countries of the EU plus Switzerland and Norway. European affiliates of Wyeth Vaccines made available recent epidemiological data on IPD from local disease surveillance programmes, including unpublished sources. Recent literature and websites were also searched to provide as wide a representation as possible. This included OVID and abstracts from a number of international meetings, dating from the year 2000. The reported rates of paediatric IPD per 100000 (age) ranged from a low of 1.7 (<2 years) to 4.2 (2-15 years) in Sweden to a high of 93.5 to 174 (<2 years) to 56.2 (<5 years) in Spain. The percentage of circulating serotypes causing IPD that are covered by 7-valent pneumococcal conjugate vaccine (PCV) IPD serotype coverage ranged from 60% to 80% for European children aged <2 years. Under reporting, differences in reporting methods, antibiotic prescribing and disparities in blood-culturing practices may explain the differences in reported disease incidence. Because of the excellent clinical efficacy of the PCV against IPD, national pneumococcal vaccination programmes in Europe have the potential to prevent much morbidity and mortality.

Cost-effectiveness of vaccinating for invasive pneumococcal disease in the elderly in the Lazio region of Italy

Pneumococcal vaccination among the elderly is currently recommended in several western countries. We estimated the cost-effectiveness of a hypothetical vaccination campaign of 65+ year olds in the Lazio region (Italy). Baseline net costs per event averted and life-year gained, at 2001 prices, were euro 34,681 (95%CI: euro 28,699 to euro 42,929) and euro 23,361, respectively (95%CI: euro 16,419 to euro 38,297). Lower bacteraemic pneumonia incidence and vaccine effectiveness increased the net cost per life-year gained (ICER) to euro 53,899 and euro 74,313, respectively; in the best-case scenario the ICER was euro 4249. The case definition of invasive pneumococcal disease and, consequently, vaccine effectiveness are major uncertainties in countries with low incidence of pneumonia.

Active surveillance of Streptococcus pneumoniae bacteremia in Italian children

There are few data published regarding the incidence of Streptococcus pneumoniae bacteremia in Italian children. A 14-month surveillance study was conducted in 10 paediatric hospitals to investigate the rate of Sp bacteremia in children aged less than 5 years. The serotype prevalence and antimicrobial susceptibility of isolates were determined. A total of 55 Sp isolates were obtained from 4576 blood cultures (incidence rate, 1.2%). In order of frequency, the most common serotypes were 14, 23F, 19F, 9V, 1. Serotypes in the 7-valent conjugate pneumococcal vaccine (4, 6B, 9V, 14, 18C, 19F, 23F) accounted for 70% of isolates under 2 years of age, and 58% in the interval between 2 and 5 years of age.

Invasive pneumococcal disease in adults in North-Rhine Westphalia, Germany, 2001-2003

A population-based survey of invasive pneumococcal disease (IPD) was conducted among adults in North-Rhine Westphalia, Germany. The study included 202 of the 386 hospitals in the region, together with the 27 microbiological laboratories that submitted reports of IPD in these hospitals to the National Reference Centre for Streptococci. The reports of 16 laboratories were comprehensively reviewed. Most (95.8%) IPD isolates were susceptible to penicillin G, but 14.5% were resistant to clarithromycin. Serotypes 14 (15.6%), 3 (9.3%), 4 (7.1%) and 7F (7.9%) were the most common. The serotype coverage of the 23-valent pneumococcal polysaccharide vaccine was 80.8%. During 2001-2003, the annual incidence of IPD, after correcting for laboratory and hospital under-reporting, was 16.2/100 000 in individuals aged >or= 65 years. In three university hospitals, blood cultures were obtained for only 37% of patients with community-acquired pneumonia, and fewer than one-third of such cultures were obtained in one hospital before antibiotics were prescribed, suggesting that the true incidence of IPD was closer to 50/100 000.