Epidemiology of Invasive Streptococcus pneumoniae Infections in Children in Spain, 1996–1998

Burden of Streptococcus pneumoniae Sepsis in Children After Introduction of Pneumococcal Conjugate Vaccines: A Prospective Population-based Cohort Study

BACKGROUND

Population-based studies assessing the impact of pneumococcal conjugate vaccines (PCV) on burden of pneumococcal sepsis in children are lacking. We aimed to assess this burden following introduction of PCV-13 in a nationwide cohort study.

METHODS

The Swiss Pediatric Sepsis Study (September 2011 to December 2015) prospectively recruited children <17 years of age with blood culture-proven sepsis due to Streptococcus pneumoniae, meeting criteria for systemic inflammatory response syndrome. Infection with vaccine serotype in children up to date with PCV immunization was defined as vaccine failure. Main outcomes were admission to pediatric intensive care unit (PICU) and length of hospital stay (LOS).

RESULTS

Children with pneumococcal sepsis (n = 117) accounted for a crude incidence of 2.0 per 100 000 children (95% confidence interval [CI] 1.7-2.4) and 25% of community-acquired sepsis episodes. Case fatality rate was 8%. Forty-two (36%) patients required PICU admission. Children with meningitis (29; 25%) were more often infected by serotypes not included in PCV (69% vs 31%; P < .001). Sixteen (26%) of 62 children up to date with PCV immunization presented with vaccine failure, including 11 infected with serotype 3. In multivariable analyses, children with meningitis (odds ratio [OR] 6.8; 95% CI 2.4-19.3; P < .001) or infected with serotype 3 (OR 2.8; 95% CI 1.1-7.3; P = .04) were more often admitted to PICU. Children infected with serotype 3 had longer LOS (β coefficient 0.2, 95% CI .1-1.1; P = .01).

CONCLUSIONS

The incidence of pneumococcal sepsis in children shortly after introduction of PCV-13 remained substantial. Meningitis mostly due to non-vaccine serotypes and disease caused by serotype 3 represented significant predictors of severity.

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.

Epidemiologic features of invasive pneumococcal disease in Belgian children: passive surveillance is not enough

BACKGROUND

Reliable epidemiologic surveillance of infectious diseases is important for making rational choices for public health issues such as vaccination strategies. In Belgium, as in most European countries, surveillance relies on voluntary passive reporting from microbiology laboratories; therefore, reported incidence rates are probably inaccurate.

METHODS

We conducted national, active, laboratory-based and clinically based surveillance of invasive pneumococcal disease in young children.

RESULTS

During the study period, the incidences of invasive pneumococcal disease in children < 2 years of age (104.4 cases per 10(5) person-years and 16.1 cases per 10(5) person-years for invasive pneumococcal disease and meningitis, respectively) and in children 0 to 59 months of age (59.5 cases per 10(5) person-years for invasive pneumococcal disease and 7.7 cases per 10(5) person-years for meningitis) were twice those reported previously through the passive surveillance system. Overall, 67% of the Streptococcus pneumoniae strains isolated from children < 5 years of age belonged to 7-valent pneumococcal conjugate vaccine serotypes and 18% to vaccine-related serotypes (mainly serotype 19A). Erythromycin resistance was frequent, especially among children < 2 years of age (59%).

CONCLUSIONS

Under-reporting can explain the reported low incidence of invasive pneumococcal disease in countries (such as Belgium) that depend on a passive epidemiologic surveillance system, which could lead to erroneous choices in vaccination policies. There is a need for an active system of epidemiologic surveillance for vaccine-preventable diseases such as invasive pneumococcal disease, at the national or European level.

Clinical characteristics and outcome of complicated pneumococcal pneumonia in a pediatric population

The incidence of complicated pneumonia caused by S. pneumoniae is reported to be increasing. This increase may be related to host susceptibility and/or pathogen virulence. The objective of this study was to evaluate clinical and laboratory characteristics associated with complicated pneumococcal pneumonia, and to identify risk factors associated with prolonged fever and hospitalization. The study involved reviewing the records of all children who were hospitalized in four major hospitals in Jerusalem with a confirmed diagnosis of pneumococcal pneumonia during a 12-year period (1986-1997). Demographic, clinical, laboratory, and outcome variables were compared between those with uncomplicated and complicated pneumonia. One hundred and eleven children (median age, 2.2 years) were hospitalized with pneumococcal pneumonia during the study period. Forty-four (39%) of them had complicated pneumonia, characterized by pleural effusion, empyema, pneumothorax, pneumatocele, and/or atelectasis. There was no correlation between the isolation of penicillin-resistant S. pneumonia (16% of cases) and complicated pneumonia. Factors that were significantly associated with complicated pneumonia included weight <or=10% for age, respiratory distress (e.g., tachypnea, dyspnea), anemia, and a white blood cell count (WBC) <15,000/mm(3) at time of admission. Complicated pneumonia and a WBC <15,000/mm(3) on admission increased the risk for prolonged fever and an extended length of hospitalization. Based on these results, it is concluded that host factors such as anemia, low weight, and a low WBC are associated with complicated pneumonia. Both the presence of pulmonary complications and a relatively low WBC in children hospitalized for pneumococcal pneumonia are independent risk factors for protracted fever and extended hospitalization.