Search

Background: The objective of this study is to describe incidence and shifts of serotype and clonal distribution of invasive Streptococcus pneumoniae strains in four different age groups (<5 years, 5–17 years, 18–64 years and >65 years) during a period of intermediate PCV13 vaccination coverage (2011–2016) in Catalonia, Spain. Methods: We included all pneumococcal strains systematically sent to the Catalan support laboratory for molecular surveillance of invasive pneumococcal disease (IPD) located at Hospital Sant Joan de Deu, Barcelona. Two study periods were considered: 2011–13, early PCV13 vaccination period (EVP) and 2014–2016, late vaccination period (LVP). Results: A total of 2142 strains were included in the study. Five years after intermediate introduction of PCV13 in our population, a significant decrease of overall incidence of IPD in children <5 years was observed (incidence rate ratio 0.5, 95% confidence interval 0.4–0.8). However, in seniors older than 65 years, a significant increase of overall incidence of IPD was observed (IRR 1.4, 95% CI 1.1–1.7). The contribution of PCV13 vaccine serotypes to IPD declined significantly in all age groups: from 59% to 38.1% in <5 years; 82.7% to 59% in 5–17 years, 47.8% to 34.1% in 18–64 years and 48.2% to 37% in >65 years. Results found when comparing both periods were consistent with IRRs observed year by year. In children <5 years, the three major serotypes detected were 1, 24F and 19A in EVP vs 24F, 14 and 10A in LVP. Among patients 5–17 years the first three serotypes were 1, 12F and 14 both in EVP and LVP. Among adults 18–64, the three major serotypes detected were 1, 12F and 8 vs 8, 12F and 3, respectively. Finally, in patients >65 years the most frequently isolated serotypes were 3, 19A and 7F vs 3, 14 and 12F, respectively. Regarding clonal complexes (CCs) expressing mainly PCV13 serotypes, significant decreases of the proportions of CC306, CC191 and CC320 were observed, while CC156 showed a significant increase. As for CCs expressing mostly non-PCV13 serotypes, significant increases in ST989, CC53 and CC404 were showed. Conclusions: Despite low vaccine coverage in our setting a significant decrease of incidence of IPD was observed in children younger than 5 years. The modest indirect protection against vaccine serotypes causing IPD in elderly indicate the need for the inclusion of more serotypes in future high-valent PCV and vaccinating old adults should be considered. [ABSTRACT FROM AUTHOR]

Objective  After the introduction of 13-valent pneumococcal conjugate vaccine (PCV13), a decrease of serotype-3 invasive pneumococcal disease (IPD) has not been homogenously observed around Europe. The aim of the study is to analyze the incidence of serotype-3 IPD in our area (Catalonia, Spain) and describe what microbiological and clinical characteristics distinguish serotype-3 IPD from nonserotype-3 IPD. Methods  This study is a prospective observational study performed in three hospitals of Barcelona (Spain), from January 2012 to June 2016. Patients younger than 18 years with a diagnosis of IPD were included. Epidemiological, clinical, and microbiological data were collected. Results  A total of 253 cases of IPD were included; of these, 53 were caused by serotype 3. The incidence rate of serotype-3 IPD remained stable over the study years (risk ratio [RR] = 0.64; 95% confidence interval [CI]: 0.3–1.38). In 92.5% (49/53) of the cases of serotype-3 IPD, the diagnosis was pneumonia and 89.8% (44/49) of them reported a complicated pneumonia. Also, 98.1% (52/53) were detected by positive real-time polymerase chain reaction (PCR) in blood or pleural effusion. Seventeen patients were properly vaccinated with PCV13 before the infection. Conclusion  After the introduction of PCV13 a global decline of invasive pneumococcal disease has been reported, specially, due to a decrease of serotypes 1 and 19A cases. Serotype-3 Streptococcus pneumoniae IPD remained stable throughout the years of study, being currently the main serotype causing IPD in our area. Serotype 3 causes mostly pneumonia and physicians must be aware of possible complications. Real-time PCR have a significantly higher diagnostic yield for serotype 3 compared with culture. Some vaccination failures were observed. [ABSTRACT FROM AUTHOR]