Characterisation of invasive pneumococcal isolates in Catalan children up to 5 years of age, 1989–2000

Epidemiology of pneumococcal diseases in Spain after the introduction of pneumococcal conjugate vaccines

In Spain, the use of pneumococcal conjugate vaccines (PCVs) has led to a decrease in the incidence of vaccine serotypes causing invasive and non-invasive disease in vaccinated and unvaccinated children and adults. Further, the coverage of most of the resistant serotypes by vaccines resulted in an overall decline in antibiotic resistance. As an undesirable effect, there was an increase in the non-vaccine serotypes causing infection, especially serotypes 1, 7F and 19A after PCV7 and serotype 8 after PCV13 approval, this making the beneficial effect of vaccination less apparent. The inclusion of PCVs in childhood vaccination schedules, its approval for use in healthy adults and the increasing number of serotypes covered by the vaccines in development are strong strategies in the fight against pneumococcal disease. Nonetheless, the epidemiology of Streptococcus pneumoniae infections must be still under surveillance to detect new changes, given the high capacity for recombination and adaptability of this always-surprising microorganism.

Cost of hospitalizing children with invasive pneumococcal pneumonia

BACKGROUND

Although invasive pneumococcal pneumonia remains responsible for a significant number of child hospitalizations, specific data on hospital resource utilization and related costs are limited.

OBJECTIVES

To assess the cost of hospitalizing children with invasive pneumococcal pneumonia and identify the cost determinants of the disease.

PATIENTS AND METHODS

Economic evaluation based on an observational study of all children <18 years of age with culture-proved invasive pneumococcal pneumonia admitted to a referral hospital in Barcelona (Spain) during the period January 2001-December 2011. Analysis included demographic, microbiological, epidemiological and clinical variables.

RESULTS

A total of 135 children were included in the study (median age 3.3 years). PCV13 serotypes were detected in 132 (97.8%) cases. Median hospital cost was €4533 (€4078-5435, 95% CI). Median length of stay was 11.0 days (10.6-13.0 days, 95% CI). Variables significantly associated with increased cost in the multivariate analysis were complicated pneumonia (≥2 and 1 complication) versus non-complicated pneumonia (€4919 and €2822 vs. €1399), performance of surgery versus no surgery (€4849 vs. €1435), intensive care versus no intensive care (€6488 vs. €3862) and identification of non-PCV7 serotypes versus PCV7 serotypes (€4656 vs. €1470).

CONCLUSION

Invasive pneumococcal pneumonia in children makes substantial demands on hospital health care and financial resources that could be mitigated with universal PCV13 childhood immunization programmes and early management of complications.

National paediatric immunization program of high risk groups: no effect on the incidence of invasive pneumococcal diseases

This study monitors the epidemiology of invasive pneumococcal diseases (IPD) in hospitalized children up to 60 months of age before (February 2001-October 2004) and after (November 2004-January 2007) the introduction of a national risk group immunization program with "Prevenar" in Austria. The IPD incidence rates, per 100,000, for IPD were 7.6 before and 6.4 after the risk group immunization program, while there was a significant reduction (p<0.05) for meningitis, 3.1 before and 1.6 after. Overall, the most commonly observed serotypes were 14 (34.2%), 6B (11.7%), and 23F (6.7%). 71.7% of the identified strains were vaccine types; 12.5% were vaccine-related serotypes. No clinically relevant changes in the incidence rate of IPDs or shift/replacement of serotypes was documented. Antimicrobial resistance predominated against erythromycin (32.5%) and clarithromycin (26.7%). Our data show that this risk group vaccination program had no impact on the incidence of IPD in young children.

Emergence of invasive pneumococcal disease caused by nonvaccine serotypes in the era of 7-valent conjugate vaccine

BACKGROUND

Little is known about the epidemiology of invasive pneumococcal disease (IPD) after the introduction of 7-valent pneumococcal conjugate vaccine (PCV7) in Spain and other European countries.

METHODS

We performed a 10-year prospective study including all children with culture-proven IPD admitted to Sant Joan de Deu Hospital, a children's center in the southern area of Barcelona, Catalonia, Spain. PCV7 was introduced in June 2001, and the current estimate of PCV7 coverage is 45%-50%.

RESULTS

Comparing the prevaccine period (1997-2001) with the vaccine period (2002-2006), among children aged <2 years, the rate of IPD increased from 32.4 episodes per 100,000 population to 51.3 episodes per 100,000 population (an increase of 58%; 95% confidence interval, 2%-145%), and among children aged 2-4 years, the rate increased from 11.3 episodes per 100,000 population to 26.5 episodes per 100,000 population (an increase of 135%; 95% confidence interval, 31%-320%). At clinical presentation, the rate of pneumonia and/or empyema among children aged <5 years increased from 3.6 episodes per 100,000 population to 15.1 episodes per 100,000 population (an increase of 320%; 95% confidence interval, 98%-790%). These increased rates of IPD were caused by non-PCV7 serotypes, which represented 38% and 72% of infecting serotypes in the prevaccine and vaccine periods, respectively (P=.001). Penicillin resistance decreased from 48% in the prevaccine period to 27% in the vaccine period (P=.005). In the vaccine period, there was an emergence of previously established virulent clones of non-PCV7 serotypes 1 and 5. There was also an increase in the prevalence of serotypes 19A and 6A expressed with different clonal types, including Spain(23F)-1 and Spain(6B)-2.

CONCLUSIONS

Since the introduction of PCV7 for children, there has been an emergence of IPD caused by virulent clones of non-PCV7 serotypes that has been associated with significant clinical changes and a decrease in antibiotic resistance.

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.

Streptococcus pneumoniae in western Europe: serotype distribution and incidence in children less than 2 years old

We did a systematic search and synthesis of evidence on the incidence of invasive pneumococcal disease, symptomatic disease, and circulating Streptococcus pneumoniae serotypes in western Europe. Using data from studies published between 1992 and 2005 we calculated a weighted mean invasive pneumococcal disease and pneumococcal meningitis incidence rate per 100,000 children aged 2 years or younger within 95% confidence intervals, together with the prevalence of S. pneumoniae serotypes and resistance to penicillin. Invasive pneumococcal disease incidence was 27.03 cases per 100,000 children under 2 years (95% CI 21.85-33.43) [corrected] Heptavalent conjugate vaccine serotypes account for 43.18-75.32% of isolates among people aged under 18 years of age. 11% of isolates in individuals aged under 18 years were penicillin resistant. The incidence of invasive pneumococcal disease appeared consistently lower in western European countries compared with studies from the USA. Thus the use of studies of vaccine effectiveness based on the US population may lead to an overestimation of the benefits of its introduction in Europe.