Serotype prevalence in adults hospitalised with pneumococcal non-invasive community-acquired pneumonia

Association between regular physical activity and pneumonia-related hospitalization according to pneumococcal vaccination status: The VENUS study

BACKGROUND

Little is known about the impact of physical activity (PA) and PPSV23 vaccination on pneumonia-related hospitalizations. This study examined the association between regular PA and pneumonia-related hospitalization according to PPSV23 vaccination status in older adults.

METHODS

This retrospective cohort study was conducted using health checkup data, medical care claims data, and vaccination records from two Japanese municipalities. Residents aged ≥65 years who had undergone a health checkup between April 2016 and March 2021 were categorized into a PPSV23 vaccinated or unvaccinated cohort. Each cohort was further divided into a PA group and no PA group. The hazard ratio (HR) of PA for pneumonia-related hospitalization was calculated for each cohort while adjusting for sex, age, comorbidities, and metabolic syndrome.

RESULTS

The vaccinated cohort comprised 16,295 participants (no PA: 5,139, PA: 11,156), and the unvaccinated cohort comprised 7,998 participants (no PA: 2,671, PA: 5,327). In the vaccinated cohort, the PA group had a significantly lower hazard for pneumonia-related hospitalization than the no PA group (adjusted HR: 0.58, P = 0.004). However, PA was not associated with pneumonia-related hospitalization in the unvaccinated cohort (adjusted HR: 0.70, P = 0.270).

CONCLUSIONS

PA can reduce the risk of pneumonia-related hospitalization in vaccinated persons. Interventions that increase both vaccination rates and PA habits may help to reduce these hospitalizations in older adults.

Emerging pneumococcal serotypes in Iraq: scope for improved vaccine development

Pneumococcal disease is a global public health concern as it affects the young, aged and the immunocompromised. The development of pneumococcal vaccines and their incorporation in the immunization programs has helped to reduce the global burden of disease. However, serotype replacement and the emergence of non-vaccine serotypes as well as the persistence of a few vaccine serotypes underscores the need for development of new and effective vaccines against such pneumococcal serotypes. In the Middle East, places of religious mass gatherings are a hotspot for disease transmission in addition to the global risk factors. Therefore, the periodic surveillance of pneumococcal serotypes circulating in the region to determine the effectiveness of existing prevention strategies and develop improved vaccines is warranted. Currently, there is a lack of serotype prevalence data for Iraq due to inadequate surveillance in the region. Thus, this review aims to determine the pneumococcal serotypes circulating in Iraq which may help in the development and introduction of improved pneumococcal vaccines in the country.

Adult non-invasive pneumococcal pneumonia in Portugal is dominated by serotype 3 and non-PCV13 serotypes 3-years after near universal PCV13 use in children

Introduction

Non-invasive pneumococcal pneumonia (NIPP) is possibly the most frequent infection by Streptococcus pneumoniae in adults. However, the herd effect of vaccinating children in adult NIPP (aNIPP) remains poorly characterized.

Methods

We determined the serotype distribution and antimicrobial susceptibility of isolates causing aNIPP (>18 years) in 2016-2018 in Portugal; 3 years with near universal vaccination of children with the 13-valent conjugate vaccine (PCV13), following over a decade of significant PCV use in children in the private market.

Results and discussion

Among the 1,149 aNIPP isolates, the most frequent serotypes detected were: 3 (n = 168, 14.6%), 11A (n = 102, 8.9%), 19F (n = 70, 6.1%), 23A and 23B (n = 62, 5.4% each), 9N (n = 60, 5.2%), 8 and 29/35B (n = 43, 3.7% each); together accounting for 53% of all isolates. The serotype distribution causing aNIPP was stable in 2016-2018, with the serotypes included in PCV7 still being important causes of disease and serotype 3, a PCV13 serotype, remaining the leading cause of aNIPP. There was an increase in penicillin non-susceptibility from 17% in 2016 to 24% in 2018 (p = 0.018). Some PCV13 serotypes, such as 14, 19A and 19F were associated to resistance, which may have contributed to their persistence. The fact that close to 20% of aNIPP is caused by four non-vaccine serotypes (23A, 23B, 9N, and 29/35B) and that there were significant differences in serotype distribution relative to invasive disease, stress the importance of maintaining the surveillance of these infections. The lack of a continued herd effect from vaccinating children and the significant fraction of aNIPP potentially preventable by PCV13 (30%), PCV15 (34%), PCV20 (53%) and the 23-valent polysaccharide vaccine (61%) underscore the importance of considering the broader use of pneumococcal vaccines in adults.

The ratio of neutrophil-to-lymphocyte and platelet-to-lymphocyte and association with mortality in community-acquired pneumonia: a derivation-validation cohort study

RATIONALE

The ratio of neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR) and platelet-to-lymphocyte (PLR) are biomarkers that have shown potential for predicting mortality in several diseases. For patients hospitalized with community-acquired pneumonia (CAP), the prognostic capabilities of these biomarkers are unknown.

OBJECTIVE

Investigate whether NLR, MLR or PLR were associated with 90-day mortality in CAP. Further, investigate whether the prediction rule CURB-65 could be improved by adding these biomarkers.

METHODS

A derivation-validation study using a Danish multicentre retrospective cohort as the derivation cohort (N = 831) and a European multicentre prospective cohort as the validation cohort (N = 2463). Associations between biomarkers and mortality were assessed using Cox proportional hazard models with adjustments for sex, CURB-65 and comorbidities. A cut-off value for biomarkers was determined using Youden's J Statistics. The performance of CURB-65 with added biomarkers was evaluated using receiver-operating characteristics.

RESULTS

In both cohorts increasing NLR and PLR were associated with 90-day mortality. In the derivation cohort, the hazard ratios for NLR and PLR were 1.016 (95% confidence interval (CI) 1.001-1.032, P = 0.038) and 1.001 (95% CI 1.000-1.001, P = 0.035), respectively. Adding these biomarkers to CURB-65 did not improve its performance.

CONCLUSIONS

NLR and PLR were associated with 90-day mortality in CAP, but did not improve CURB-65.

Prevalence of Pneumococcal Serotypes in Community-Acquired Pneumonia among Older Adults in Italy: A Multicenter Cohort Study

Pneumococcal community-acquired pneumonia (CAP) is a leading cause of mortality. Following the introduction of pneumococcal conjugate vaccines (PCVs) in children, a decrease in the burden of the disease was reported. In parallel, an increase in non-vaccine serotypes was also noted. The objective of this study was to assess the current serotype-specific epidemiology of pneumococci among Italian older adults hospitalized for CAP. A prospective study was conducted between 2017 and 2020 in four Italian regions. Subjects aged ≥65 years hospitalized with confirmed CAP were tested for pneumococci using both pneumococcal urinary antigen and serotype-specific urine antigen tests able to identify all 24 serotypes included in the available vaccines. Of the 1155 CAP cases, 13.1% were positive for pneumococci. The most prevalent serotypes were 3 (2.0%), 8 (1.7%), 22F (0.8 %) and 11A (0.7%). These serotypes are all included in the newly licensed PCV20. The serotypes included in PCV13, PCV15 and PCV20 contributed to 3.3%, 4.4% and 7.5% of the CAP cases, respectively. In the context of a low PCV13 coverage among older adults and a high PCV coverage in children, a substantial proportion of CAP is caused by PCV13 serotypes. Higher valency PCV15 and PCV20 may provide additional benefits for the prevention of CAP in vaccinated older adults.

Aging and Mesenchymal Stem Cells: Basic Concepts, Challenges and Strategies

Aging and frailty are complex processes implicating multifactorial mechanisms, such as replicative senescence, oxidative stress, mitochondrial dysfunction, or autophagy disorder. All of these mechanisms drive dramatic changes in the tissue environment, such as senescence-associated secretory phenotype factors and inflamm-aging. Thus, there is a demand for new therapeutic strategies against the devastating effects of the aging and associated diseases. Mesenchymal stem cells (MSC) participate in a "galaxy" of tissue signals (proliferative, anti-inflammatory, and antioxidative stress, and proangiogenic, antitumor, antifibrotic, and antimicrobial effects) contributing to tissue homeostasis. However, MSC are also not immune to aging. Three strategies based on MSC have been proposed: remove, rejuvenate, or replace the senescent MSC. These strategies include the use of senolytic drugs, antioxidant agents and genetic engineering, or transplantation of younger MSC. Nevertheless, these strategies may have the drawback of the adverse effects of prolonged use of the different drugs used or, where appropriate, those of cell therapy. In this review, we propose the new strategy of "Exogenous Restitution of Intercellular Signalling of Stem Cells" (ERISSC). This concept is based on the potential use of secretome from MSC, which are composed of molecules such as growth factors, cytokines, and extracellular vesicles and have the same biological effects as their parent cells. To face this cell-free regenerative therapy challenge, we have to clarify key strategy aspects, such as establishing tools that allow us a more precise diagnosis of aging frailty in order to identify the therapeutic requirements adapted to each case, identify the ideal type of MSC in the context of the functional heterogeneity of these cellular populations, to optimize the mass production and standardization of the primary materials (cells) and their secretome-derived products, to establish the appropriate methods to validate the anti-aging effects and to determine the most appropriate route of administration for each case.

Pneumococcal serotypes in adults hospitalized with community-acquired pneumonia in Greece using urinary antigen detection tests: the EGNATIA study, November 2017 - April 2019

Greece introduced a 13-valent pneumococcal conjugate vaccine (PCV13) into the infant national immunization program in 2010 (3 + 1 schedule until June 2019). Since 2015, PCV13 has been recommended for adults aged 19-64 years with comorbidities and adults ≥65 years sequentially with 23-valent pneumococcal polysaccharide vaccine (PPSV23). We examined pneumococcal serotype distribution among Greek adults aged ≥19 years hospitalized with community-acquired pneumonia (CAP) during November 2017-April 2019. This was an interim analysis of EGNATIA, a prospective study of adult hospitalized CAP in the cities of Ioannina and Kavala. Pneumococcus was identified using cultures, BinaxNow®, serotype-specific urinary antigen detection assays (UAD-1/2). Our analysis included overall 482 hospitalized CAP patients (mean age: 70.5 years; 56.4% male). 53.53% of patients belonged to the highest pneumonia severity index (PSI) classes (IV-V). Pneumococcus was detected in 65 (13.5%) patients, with more than half (57%) of cases detected only by UAD. Approximately two-thirds of pneumococcal CAP occurred in those aged ≥65 years (n = 40, 8.3% of CAP). More than half of pneumococcal CAP (n = 35, 53.8%) was caused by PCV13 serotypes. Most frequently detected PCV13 serotypes were 3, 19A, 23F, collectively accounting for 83% of PCV13 vaccine-type (VT) CAP and 6% of all-cause CAP. Overall, 82.9% of PCV13 VT CAP occurred among persons with an indication (age/risk-based) for PCV13 vaccination. Even with a mature PCV13 childhood immunization program, a persistent burden of PCV13 VT CAP exists in Greek adults. Strategies to increase PCV13 (and higher-valency PCVs, when licensed) coverage in adults should be implemented to reduce the disease burden.

High prevalence of multiple serotypes of pneumococci in patients with pneumonia and their associated risk factors

BACKGROUND

Multiple serotypes of pneumococci have epidemiological and clinical implications, such as the emergence of non-vaccine serotypes and the acquisition of antimicrobial resistance. Prevalence of multiple serotypes of pneumococci in adults and their risk factors are not known.

METHODS

We enrolled adult patients from age ≥15 years with radiologically confirmed pneumonia in four hospitals across Japan. Pneumococcal pneumonia was defined with a pneumococcal bacterial density of ≥104/mL in sputum by lytA quantitative PCR, and serotypes were determined. Pneumonias with a single serotype were categorised as single-serotype pneumococcal pneumonia and with two or more serotypes as multiple-serotype pneumococcal pneumonia. Multivariable logistic regression was used to assess the risk factors.

RESULTS

3470 patients (median age 77 years, IQR 65-85) were enrolled. Pneumococcal pneumonia was identified in 476 (18.3%, n=2605) patients. Multiple serotypes were detected in 42% of them. Risk of having multiple serotypes was low among patients who had received 23-valent pneumococcal polysaccharide vaccine (PPSV23) vaccines (adjusted OR 0.51 (95% CI 0.27 to 0.94)). Proportion of non-PCV7 PPSV23 serotypes in overall distribution of multiple serotypes was 67.4% (n=324/481) compared with 46.4% (n=128/276) in that of single serotypes (p=0.001). Serotypes 5, 9N/9L, 10A, 12/22/46, 17F and 35F were associated with multiple-serotype pneumonia, and serotypes 6A/6B, 23F, 11 and 6C/6D were associated with single-serotype pneumonia. Proportion of more invasive serotypes (serotypes 1, 5, 7F, 8) was significantly higher in multiple-serotype pneumonia (p=0.001).

CONCLUSIONS

Multiple serotypes of pneumococci are common in sputum of adult patients with pneumonia. The risk of multiple-serotype pneumococcal pneumonia is lower than that of single-serotype pneumococcal pneumonia among PPSV23-vaccinated patients.

TRIAL REGISTRATION NUMBER

UMIN000006909.

Pneumococcal serotypes causing non-invasive pneumonia in adults from a South Indian tertiary care hospital and the impact of the newer conjugate vaccines

Background

Streptococcus pneumoniae is the leading cause of community-acquired pneumonia (CAP) in adults. Ageing, chronic conditions and comorbidities are important risk factors for pneumococcal pneumonia.

Purpose

There is lack of data on the pneumococcal serotypes causing non-invasive pneumonia in India. This study aims to determine the prevalent pneumococcal serotypes causing non-invasive pneumonia, the associated comorbidities, and the coverage of both the available pneumococcal vaccines in India and conjugate vaccines that are currently undergoing clinical trials.

Methods

A total of 280 subjects (aged >16 years) who had clinical symptoms correlating with radiological findings for non-invasive bacteremic pneumonia and microbiological evidence of S. pneumoniae between 2018 and 2020 were included. The clinical, demographic, radiological and microbiological findings were retrieved from the Hospital Information System (HIS).

Result

The common serotypes in order of prevalence were 19F, 9V, 23F, 6B, 11A, 13, 34, 10A, 19A and 6A. The predominant non-vaccine serotypes were 13, 34, 35B, 31 and 16F. The associated radiological findings were pneumonic consolidation and multi-lobar involvement. Other coinfected bacterial pathogens included H. influenzae, S. aureus, K. pneumoniae and P. aeruginosa.

Conclusion

The pneumococcal vaccines: PCV10/GSK, PCV10/SII, PCV13, PCV15, PCV20 and PPSV23 provide an overall serotype coverage of 36, 41, 47, 48, 61 and 69 %, respectively of S. pneumoniae causing non-invasive pneumonia in South India. Increasing catch-up vaccination using PCV10(SII) in pre-school children could have a more significant impact on reducing pneumococcal pneumonia in adults (>50 years) in terms of increased herd immunity at an affordable cost.

The epidemiologic and biologic basis for classifying older age as a high-risk, immunocompromising condition for pneumococcal vaccine policy

INTRODUCTION

Immunosenescence is a normal biologic process involving deterioration of protective immune responses. Consequently, older adults experience increased risk of infectious diseases, particularly pneumonia, and its leading bacterial cause, Streptococcus pneumoniae. Pneumococcal vaccine recommendations are often limited to adults with specific medical conditions despite similar disease risks among older adults due to immunosenescence.

AREAS COVERED

This article reviews epidemiologic, biologic, and clinical evidence supporting the consideration of older age due to immunosenescence as an immunocompromising condition for the purpose of pneumococcal vaccine policy and the role vaccination can play in healthy aging.

EXPERT OPINION

Epidemiologic and biologic evidence suggest that pneumococcal disease risk increases with age and is comparable for healthy older adults and younger adults with immunocompromising conditions. Because immunocompromising conditions are already indicated for pneumococcal conjugate vaccines (PCVs), a comprehensive public health strategy would also recognize immunosenescence. Moreover, older persons should be vaccinated before reaching the highest risk ages, consistent with the approach for other immunocompromising conditions. To facilitate PCV use among older adults, vaccine technical committees (VTCs) could classify older age as an immunocompromising condition based on the process of immunosenescence. With global aging, VTCs will need to consider immunosenescence and vaccine use during healthy aging.

Potential of Mesenchymal Stem Cells in the Rejuvenation of the Aging Immune System

Rapid growth of the geriatric population has been made possible with advancements in pharmaceutical and health sciences. Hence, age-associated diseases are becoming more common. Aging encompasses deterioration of the immune system, known as immunosenescence. Dysregulation of the immune cell production, differentiation, and functioning lead to a chronic subclinical inflammatory state termed inflammaging. The hallmarks of the aging immune system are decreased naïve cells, increased memory cells, and increased serum levels of pro-inflammatory cytokines. Mesenchymal stem cell (MSC) transplantation is a promising solution to halt immunosenescence as the cells have excellent immunomodulatory functions and low immunogenicity. This review compiles the present knowledge of the causes and changes of the aging immune system and the potential of MSC transplantation as a regenerative therapy for immunosenescence.

A Systematic Review and Meta-Analysis of Serotype Distribution of Streptococcus Pneumoniae in Iran: Practical Evidence to Optimizing Local Vaccination Protocols

BACKGROUND

Little is known regarding the burden of predominant circulating serotypes of Streptococcus pneumoniae in Iran. Therefore, this study aimed to investigate the serotype distribution of pneumococcal diseases in Iran by using a comprehensive systematic review of available articles. ; Methods: A systematic literature search was carried out to identify papers published by Iranian authors in the Web of Science, PubMed, Scopus, Embase and Google Scholar electronic databases from January 2000 to December 2018. Then, eight publications that met our inclusion criteria were selected for data extraction and analysis by Comprehensive Meta-Analysis software. ; Results: In total, three studies reported the distribution of S. pneumoniae serotypes among patients, two studies among healthy individuals, and three studies among both groups. Of those studies, serotype 19A/F (17.9%; 95% CI: 13.6-23.0) was the most circulating serotype followed by 23A/F (12.3%; 95% CI: 7.7-19.2), 6A/B (11.0%; 95% CI: 8.0-14.9), and 14 (8.8%; 95% CI: 5.8-13.2). In contrast, the lowest circulating serotype was 60 (0.02%; 95% CI: 0.0-1.2), 29 (0.07%; 95% CI: 0.01-5.0), and 36 (0.09%; 95% CI: 0.04-2.1). Meta-regression results showed that prevalence of serotype 23A/F significantly increased each year about 0.2% (95% CI: 0.1-0.3, P <0.001, tau2 <0.001). ; Conclusion: In the present study, it was found that over the last decade, the most prevalent serotypes in Iran were 19, 23, 6, and 14, respectively. These findings provide practical evidence to select effective pneumococcal vaccine candidates for the prevention of invasive diseases in Iranian patients and also to compare our situation with others.

Pneumococcal serotype-specific cut-offs based on antibody responses to pneumococcal polysaccharide vaccination in healthy adults

Antibody responses to pneumococcal polysaccharide vaccination are frequently used as a diagnostic tool for humoral immunodeficiencies, part of the larger collection of inborn errors of immunity. Currently, arbitrary criteria, such as a serotype specific titer of >/= 1.3 µg/mL is most often used as a cut-off for interpretation of pneumococcal antibody responses. The magnitude of the antibody response to each of the 23 serotypes in Pneumovax®, and serotype-specific cut-offs in healthy pneumococcal vaccine-naïve adults has not been previously characterized. IgG antibody concentrations were measured prospectively for 23 pneumococcal serotypes pre and 4-6 weeks post-Pneumovax® vaccination in 100 healthy adults, using a multiplex bead-based assay. Antibodies to 19 of 23 serotypes were informative for distinguishing subjects who responded to vaccination, and the serotype threshold was determined to be 9 of 19 serotypes, which characterized an antibody response to pneumococcal vaccination. While this study may facilitate classification of IgG serotype-specific antibody responses post-pneumococcal vaccination in adult patients undergoing diagnostic immunological evaluation for antibody immunodeficiencies or other relevant contexts, additional studies in healthy children and S. pneumoniae protein-conjugate-vaccinated healthy adults will need to be undertaken in the future.

Epidemiology of community-acquired pneumonia in the era of extended serotype-covering multivalent pneumococcal conjugate vaccines

BACKGROUND

South Korea has been providing 10-valent pneumococcal conjugate vaccine/(PCV10)/13-valent pneumococcal conjugate vaccine (PCV13) to children and 23-valent pneumococcal polysaccharide vaccine (PPSV23) to older adults as part of a national immunization program.

METHODS

From September 2015 to August 2017, a prospective cohort study was conducted for adults aged ≥19 years with community-acquired pneumonia (CAP) at four university hospitals. All-cause and pneumococcal CAP incidence and mortality rates were evaluated on the basis of hospital catchment population. Serotype distribution of pneumococcal CAP was also evaluated.

RESULTS

Among 2669 patients with CAP, 252 cases (9.4%) were pneumococcal CAP cases. The annual incidences of all-cause and pneumococcal CAP were 194.3 cases and 18.3 cases respectively, per 100,000 persons. Serotyped Streptococcus pneumoniae was identified in 107 cases (42.5%) through culture or a serotype-specific urinary antigen detection assay. Pneumococcal CAP caused by the PCV13 and PPSV23 serotypes were 50 cases (46.7% of serotyped pneumococcal CAP and 19.8% of pneumococcal CAP), and 83 cases (77.6% of serotyped pneumococcal CAP and 32.9% of pneumococcal CAP), respectively. The most prevalent serotype was 3 (n = 21, 19.6% of serotyped pneumococcal CAP), followed by 19A (n = 10, 9.3% of serotyped pneumococcal CAP) and 11A (n = 10, 9.3% of serotyped pneumococcal CAP). Compared with non-pneumococcal CAP patients, pneumococcal CAP patients were more likely to have a higher CURB-65 scores (P = 0.002). The overall 30-day mortality rate of pneumococcal CAP was higher than that of non-pneumococcal CAP (6.3% versus 5.6%; odds ratio [OR], 1.15; 95% confidence interval [CI], 0.67-1.96), but this trend was reversed in patients aged 65-74 years (4.2% versus 8.6%; OR, 0.47; 95% CI, 0.14-1.54).

CONCLUSIONS

The disease burden of PCV13-serotype pneumococcal CAP remains significantly high in Korean adults, particularly among elderly people, even after a high uptake of pediatric PCVs.

Impact of 13Valent Vaccine for Prevention of Pneumococcal Diseases in Children and Adults at Risk: Possible Scenarios in Campania Region

BACKGROUND

Pneumonias are the most frequent infectious diseases, characterized by a high prevalence especially among children and adults at risk. The socio-economic impact caused by Streptococcus pneumoniae is evaluated in terms of morbidity, death rate and hospitalizations.

OBJECTIVE

The aim of the study was to demonstrate the potential economic advantages by implementation of an active anti-pneumococcal 13-valent vaccine strategy in Campania region (Southern Italy) in two different categories of subjects, children (aged 0-12), and adults (aged 50- 79) at risk (hypertension, nephropathies, COPD and heart diseases).

METHODS

Vaccination costs were compared with costs necessary to treat avoidable diseases in the presence and absence of a vaccination program.

RESULTS

Offering anti-pneumococcal 13-valent vaccine to the paediatric population was quantified as saving one million euros for Italian national health service in two years. In addition, offering anti-pneumococcal vaccine to adults at risk would generate a return of around 29 million euros.

CONCLUSION

In both cases, offering anti-pneumococcal 13-valent vaccine was proven to be a helpful political health strategy, not only in consideration of a reduction of cases but also in view of the favourable economic impacts.

Pneumococcal serotype trends, surveillance and risk factors in UK adult pneumonia, 2013-18

BACKGROUND

Changes over the last 5 years (2013-18) in the serotypes implicated in adult pneumococcal pneumonia and the patient groups associated with vaccine-type disease are largely unknown.

METHODS

We conducted a population-based prospective cohort study of adults admitted to two large university hospitals with community-acquired pneumonia (CAP) between September 2013 and August 2018. Pneumococcal serotypes were identified using a novel 24-valent urinary monoclonal antibody assay and from blood cultures. Trends in incidence rates were compared against national invasive pneumococcal disease (IPD) data. Persons at risk of vaccine-type pneumonia (pneumococcal conjugate vaccine (PCV)13 and pneumococcal polysaccharide vaccine (PPV)23) were determined from multivariate analyses.

FINDINGS

Of 2934 adults hospitalised with CAP, 1075 (36.6%) had pneumococcal pneumonia. The annual incidence of pneumococcal pneumonia increased from 32.2 to 48.2 per 100 000 population (2013-18), predominantly due to increases in PCV13non7-serotype and non-vaccine type (NVT)-serotype pneumonia (annual incidence rate ratio 1.12, 95% CI 1.04 to 1.21 and 1.19, 95% CI 1.10 to 1.28, respectively). Incidence trends were broadly similar to IPD data. PCV13non7 (56.9% serotype 3) and PPV23non13 (44.1% serotype 8) serotypes were identified in 349 (32.5%) and 431 (40.1%) patients with pneumococcal pneumonia, respectively. PCV13-serotype pneumonia (dominated by serotype 3) was more likely in patients in the UK pneumococcal vaccination clinical risk group (adjusted OR (aOR) 1.73, 95% CI 1.31 to 2.28) while PPV23-serotype pneumonia was more likely in patients outside the clinical risk group (aOR 1.54, 95% CI 1.13 to 2.10).

INTERPRETATION

The incidence of pneumococcal CAP is increasing, predominantly due to NVT serotypes and serotype 3. PPV23-serotype pneumonia is more likely in adults outside currently identified clinical risk groups.

Limited indirect effects of an infant pneumococcal vaccination program in an aging population

BACKGROUND

A general recommendation for adult pneumococcal vaccination with 23-valent polysaccharide vaccine (PPV23) for adults 60 and older has been in place in Germany since 1998, but uptake has been low. Just over a decade after the implementation of an infant pneumococcal conjugate vaccine recommendation, we examined indirect protection effects on adult invasive pneumococcal disease (IPD) in Germany.

METHODS AND FINDINGS

Reported IPD cases decreased in children under two years of age from 11.09 per 100,000 in 2003-2006 to 5.94 per 100,000 in 2017/18, while in adult age groups, reported IPD cases rose across the board, most dramatically in adults 60 years of age and over, from 1.64 to 10.08 cases per 100,000. PCV13-type IPD represents 31% of all cases in this age group, the lion's share of which is due to the rapid increase of serotype 3 IPD, which, by itself, has reached 2.11 reported cases per 100,000 and makes up 21% of all IPD cases in this age group. The two vaccine formulations currently in development (PCV15 and PCV20) would increase current (PCV13) coverage by 8.5% points and 28.0% points in children, while in adults coverage would increase by 10.4% points and 21.9% points, respectively.

CONCLUSIONS

While original models predicted that indirect effects of childhood vaccination would suffice for adults, it seems that the herd protection effect has reached its limit, with vaccine serotypes 4, 19F, and 19A IPD persisting in adults after initial reductions, and serotype 3 IPD not showing any herd protection effect at all.

Hospital-onset adult invasive pneumococcal disease in Israel: Sicker patients, different pathogens

OBJECTIVES

Invasive pneumococcal disease (IPD) usually has its onset in the community (CO-IPD), but it can commence following hospitalization (HO-IPD). This study compared HO-IPD and CO-IPD cases during the implementation of the pneumococcal conjugate vaccine (PCV) program for children in Israel.

METHODS

This was a nationwide retrospective cohort study of adult (age >18 years) IPD patients covering the period from the implementation of the PCV7/13 program in 2009/2010 through 2015. HO-IPD and CO-IPD were defined as IPD with onset ≥4 and ≤2 days from admission, respectively. Patient characteristics, outcome measures, serotypes, and antimicrobial susceptibility were compared for the entire cohort, followed by a matched case-control analysis.

RESULTS

The study included 114 patients with HO-IPD and 2180 with CO-IPD. After matching HO-IPD to CO-IPD patients by age, sex, and comorbidities, the mortality rate and discharge to long-term care facility rate were significantly higher for HO-IPD patients than for CO-IPD patients (44.6% vs. 26.3% and 26.5% vs. 8.2%, respectively). HO-IPD isolates were less often covered by PCV13 (39.6% vs. 49.0%) and pneumococcal polysaccharide vaccine PPSV23 (56.6% vs. 71.3%) and more often resistant to penicillin (9.3% vs. 3.6%), ceftriaxone (3.8% vs. 0.75%), and levofloxacin (9.3% vs. 0.8%).

CONCLUSIONS

HO-IPD was associated with higher morbidity and mortality than CO-IPD and was more often caused by non-vaccine serotypes (primarily non-PCV13 types) and antibiotic-resistant strains.

Exploring the costs of a 13-valent pneumococcal conjugate vaccination program for home care patients

OBJECTIVE

The city of Joensuu in Finland vaccinated 409 elderly home care patients with the 13-valent pneumococcal conjugate vaccine (PCV13) in autumn 2012. All home care patients were also eligible for a seasonal influenza vaccine. The objective of this retrospective real-world data cohort study was to evaluate whether the immunization intervention with PCV13 for home care patients was cost saving from the payer's (municipality's) perspective in terms of a return on investment (ROI).

METHODS

This was a retrospective observational registry study. We used registry data from the regional Mediatri patient information system covering all North Karelian municipalities, including individual-level data for all health and social care service utilization, diagnoses and procedures. Home care patients and their use of services were followed for 2 years. Cost comparisons were based on two specifications: (1) pneumonia-related health care costs; and (2) total health care costs. We compared patients who had received both influenza and PCV13 vaccinations to patients only vaccinated against influenza.

RESULT

The pneumonia-related costs in the PCV13-vaccinated group were 434 EUR lower and the total health care costs 3800 EUR lower per person, compared to the non-PCV13-vaccinated group (bootstrapped 95% CIs -1682-527 EUR and -8233-621 EUR, respectively). PCV13 vaccination was associated with a return on investment of 7 EUR per 1 EUR spent during the 2 year follow-up period when pneumonia-related costs were used as baseline. Probability of the positive return on investment was .715.

CONCLUSION

The results suggest that vaccinating home care patients could potentially be cost saving from the health care and service producer's perspectives. The uncertainty from the decision-making perspective was due to the large variation in individual costs.

Dynamic transmission modelling to address infant pneumococcal conjugate vaccine schedule modifications in the UK

The 13-valent pneumococcal conjugate vaccine (PCV) has been part of routine immunisation in a 2 + 1 schedule (two primary infant doses and one booster during the second year of life) in the UK since 2010. Recently, the UK's Joint Committee on Vaccination and Immunisation recommended changing to a 1 + 1 schedule while conceding that this will increase disease burden; however, uncertainty remains on how much pneumococcal burden – including invasive pneumococcal disease (IPD) and non-invasive disease – will increase. We built a dynamic transmission model to investigate this question. The model predicted that a 1 + 1 schedule would incur 8777–27 807 additional cases of disease and 241–743 more deaths over 5 years. Serotype 19A caused 55–71% of incremental IPD cases. Scenario analyses showed that booster dose adherence, effectiveness against carriage and waning in a 1 + 1 schedule had the most influence on resurgence of disease. Based on the model assumptions, switching to a 1 + 1 schedule will substantially increase disease burden. The results likely are conservative since they are based on relatively low vaccine-type pneumococcal transmission, a paradigm that has been called into question by data demonstrating an increase of IPD due to several vaccine serotypes during the last surveillance year available.

Evolving Understanding of the Causes of Pneumonia in Adults, With Special Attention to the Role of Pneumococcus

Before 1945, Streptococcus pneumoniae caused more than 90% of cases of pneumonia in adults. After 1950, the proportion of pneumonia caused by pneumococcus began to decline. Pneumococcus has continued to decline; at present, this organism is identified in fewer than fewer10%-15% of cases. This proportion is higher in Europe, a finding likely related to differences in vaccination practices and smoking. Gram-negative bacilli, Staphylococcus aureus, Chlamydia, Mycoplasma, and Legionella are each identified in 2%-5% of patients with pneumonia who require hospitalization. Viruses are found in 25% of patients, up to one-third of these have bacterial coinfection. Recent studies fail to identify a causative organism in more than 50% of cases, which remains the most important challenge to understanding lower respiratory infection. Our findings have important implications for antibiotic stewardship and should be considered as new policies for empiric pneumonia management are developed.

Sequencing of the variable region of rpsB to discriminate between Streptococcus pneumoniae and other streptococcal species

The vast majority of streptococci colonizing the human upper respiratory tract are commensals, only sporadically implicated in disease. Of these, the most pathogenic is Mitis group member, Streptococcus pneumoniae Phenotypic and genetic similarities between streptococci can cause difficulties in species identification. Using ribosomal S2-gene sequences extracted from whole-genome sequences published from 501 streptococci, we developed a method to identify streptococcal species. We validated this method on non-pneumococcal isolates cultured from cases of severe streptococcal disease (n = 101) and from carriage (n = 103), and on non-typeable pneumococci from asymptomatic individuals (n = 17) and on whole-genome sequences of 1157 pneumococcal isolates from meningitis in the Netherlands. Following this, we tested 221 streptococcal isolates in molecular assays originally assumed specific for S. pneumoniae, targeting cpsA, lytA, piaB, ply, Spn9802, zmpC and capsule-type-specific genes. Cluster analysis of S2-sequences showed grouping according to species in line with published phylogenies of streptococcal core genomes. S2-typing convincingly distinguished pneumococci from non-pneumococcal species (99.2% sensitivity, 100% specificity). Molecular assays targeting regions of lytA and piaB were 100% specific for S. pneumoniae, whereas assays targeting cpsA, ply, Spn9802, zmpC and selected serotype-specific assays (but not capsular sequence typing) showed a lack of specificity. False positive results were over-represented in species associated with carriage, although no particular confounding signal was unique for carriage isolates.

IL-17 can be protective or deleterious in murine pneumococcal pneumonia

Streptococcus pneumoniae is the major bacterial cause of community-acquired pneumonia, and the leading agent of childhood pneumonia deaths worldwide. Nasal colonization is an essential step prior to infection. The cytokine IL-17 protects against such colonization and vaccines that enhance IL-17 responses to pneumococcal colonization are being developed. The role of IL-17 in host defence against pneumonia is not known. To address this issue, we have utilized a murine model of pneumococcal pneumonia in which the gene for the IL-17 cytokine family receptor, Il17ra, has been inactivated. Using this model, we show that IL-17 produced predominantly from γδ T cells protects mice against death from the invasive TIGR4 strain (serotype 4) which expresses a relatively thin capsule. However, in pneumonia produced by two heavily encapsulated strains with low invasive potential (serotypes 3 and 6B), IL-17 significantly enhanced mortality. Neutrophil uptake and killing of the serotype 3 strain was significantly impaired compared to the serotype 4 strain and depletion of neutrophils with antibody enhanced survival of mice infected with the highly encapsulated SRL1 strain. These data strongly suggest that IL-17 mediated neutrophil recruitment to the lungs clears infection from the invasive TIGR4 strain but that lung neutrophils exacerbate disease caused by the highly encapsulated pneumococcal strains. Thus, whilst augmenting IL-17 immune responses against pneumococci may decrease nasal colonization, this may worsen outcome during pneumonia caused by some strains.

Burden of pneumococcal community-acquired pneumonia in adults across Europe: A literature review

BACKGROUND

The burden of community-acquired pneumonia (CAP) caused by Streptococcus pneumoniae (pneumococcus) among adults in Europe is poorly defined.

METHODS

Structured searches of PubMed were conducted to identify the incidence of pneumococcal CAP among adults across Europe.

RESULTS

The overall incidence rates for CAP was 68-7000 per 100,000 and the incidence in hospitalised CAP cases of all causes was 16-3581 per 100,000. In general the incidence of CAP increased consistently with age. Available data indicated higher burdens of pneumococcal CAP caused in groups with more comorbidities. Most cases of pneumococcal CAP (30%-78%) were caused by serotypes covered by PCV13 vaccine; the incidence of PCV13-related pneumonia decreased after the introduction of childhood vaccination.

CONCLUSIONS

We observed a high burden adult pneumococcal CAP in Europe despite use of the 23-valent pneumococcal polysaccharide vaccine, particularly in elderly patients with comorbidities. CAP surveillance presented wide variations across Europe. Pneumococcal CAP has to be monitored very carefully due to the possible effect of current vaccination strategies.

Identification of prognostic factors for activities of daily living in elderly patients after hospitalization for acute infectious disease in Japan: A 6-month follow-up study

AIM

We investigated factors that predict the prognosis of activities of daily living (ADL) in elderly patients who had undergone rehabilitation during hospitalization for acute infectious disease.

METHODS

The present prospective cohort study included 131 patients who were hospitalized due to acute infectious disease and who had undergone rehabilitation during hospitalization. Patient characteristics collected from medical records included age, sex and comorbidity score. The level of ADL 2 weeks before admission was assessed by interview at the start of rehabilitation. Grip strength testing, Short Physical Performance Battery as an assessment of lower limb function and the Mini-Mental State Examination as an assessment of cognitive status were carried out at the time of hospital discharge. The level of ADL at 6 months after discharge was assessed by telephone interview. Multivariate logistic regression analysis was used to identify factors that independently predict ADL dependence (defined as being dependent in one or more ADL items at 6 months after discharge).

RESULTS

The average age of participants was 81.5 years, and 52.7% were women. A total of 22.1% of patients showed dependence in an ADL at 6-month follow-up. Factors that predicted an ADL dependence were comorbidity score (OR 4.19, 95% CI 1.19-14.69) and lower limb function (OR 0.51, 95% CI 0.36-0.72) at discharge.

CONCLUSIONS

The present findings have implications for the healthcare planning and well-being of elderly patients during hospitalization and after discharge. Geriatr Gerontol Int 2018; 18: 615-622.

Pneumococcal conjugate vaccine use for the prevention of pneumococcal disease in adults <50 years of age

INTRODUCTION

Adults, particularly those with underlying chronic conditions, eg, cardiovascular, liver, and pulmonary diseases and diabetes mellitus, have a persistent pneumococcal disease burden. Thirteen-valent pneumococcal conjugate vaccine (PCV13) is recommended in the United States for all adults aged ≥65 years and immunocompromised adults aged <65 years to protect against vaccine-serotype (VT) invasive pneumococcal disease (IPD) and pneumonia. PCV13 is not recommended for immunocompetent adults aged ≥18 years with comorbidities associated with increased pneumococcal disease risk.

AREAS COVERED

This US-focused review summarizes PCV13-type IPD and community-acquired pneumonia burden in adults aged <50 years, PCV13 immunogenicity and safety in this population, and adult pneumococcal vaccination recommendations.

EXPERT COMMENTARY

Considering (i) PCV13 has demonstrated efficacy against VT-IPD and pneumonia in adults aged ≥65 years (with or without underlying chronic conditions), and (ii) immune responses to PCV13 in younger adults are comparable or better than in older adults, PCV13 would likely have similar efficacy in adults aged <50 years. Recommending PCV13 for at-risk adults aged <50 years would provide direct immunologic benefit of a conjugate vaccine and could address an important unmet medical need for pneumococcal pneumonia prevention. Although not directly addressed here, this benefit would likely extend to at-risk adults aged 50-64 years.

Development of an Extended-Specificity Multiplex Immunoassay for Detection of Streptococcus pneumoniae Serotype-Specific Antigen in Urine by Use of Human Monoclonal Antibodies

Current pneumococcal vaccines cover the 10 to 23 most common serotypes of the 92 presently described. However, with the increased usage of pneumococcal-serotype-based vaccines, the risk of serotype replacement and an increase in disease caused by nonvaccine serotypes remains. Serotype surveillance of pneumococcal infections relies heavily on culture techniques, which are known to be insensitive, particularly in cases of noninvasive disease. Pneumococcal-serotype-specific urine assays offer an alternative method of serotyping for both invasive and noninvasive disease. However, the assays described previously cover mainly conjugate vaccine serotypes, give little information about circulating nonvaccine serotypes, and are currently available only in one or two specialist laboratories. Our laboratory has developed a Luminex-based extended-range antigen capture assay to detect pneumococcal-serotype-specific antigens in urine samples. The assay targets 24 distinct serotypes/serogroups plus the cell wall polysaccharide (CWP) and some cross-reactive serotypes. We report that the assay is capable of detecting all the targeted serotypes and the CWP at 0.1 ng/ml, while some serotypes are detected at concentrations as low as 0.3 pg/ml. The analytical serotype specificity was determined to be 98.4% using a panel of polysaccharide-negative urine specimens spiked with nonpneumococcal bacterial antigens. We also report clinical sensitivities of 96.2% and specificities of 89.9% established using a panel of urine specimens from patients diagnosed with community-acquired pneumonia or pneumococcal disease. This assay can be extended for testing other clinical samples and has the potential to greatly improve serotype-specific surveillance in the many cases of pneumococcal disease in which a culture is never obtained.

Role of Streptococcus pneumoniae infection in chronic obstructive pulmonary disease patients in Italy

Background:

The aim of this study was to determine the incidence of exacerbations due to Streptococcus pneumoniae in chronic obstructive pulmonary disease (COPD) patients during stable state.

Methods:

We conducted a prospective, observational, cohort study including stable COPD patients, who were evaluated at least every 4 months over a 24-month period at the Respiratory Unit of the IRCCS Policlinico Hospital in Milan, Italy, from 2012 to 2015. Sputum samples were collected at enrollment during stable state to evaluate the frequency of S. pneumoniae colonization and in case of an acute exacerbation to evaluate the incidence of pneumococcal infection.

Results:

A total of 79 stable patients with moderate to very severe COPD were enrolled. A total of 217 samples were collected, and 27% (n = 59) of those were positive for S. pneumoniae. A total of four exacerbations due to S. pneumoniae occurred during follow up (0.31 per 100 person/month). Among positive samples of S. pneumoniae, 109 serotypes were identified. The most frequent serotypes in moderate-to-severe COPD patients during both stable state and exacerbation were 19F (12%), 18 (10%), 19A and 9V (9%) and 35 F (7%). Only 32% of COPD patients were effectively vaccinated for S. pneumoniae with PPV23 vaccine.

Conclusion:

The most frequent S. pneumoniae serotypes in COPD patients are 19F, 18, 19A, 9V and 35 F, and that almost 50% of S. pneumoniae strains could be covered by PCV13 in adult COPD patients.

The burden of PCV13 serotypes in hospitalized pneumococcal pneumonia in Spain using a novel urinary antigen detection test. CAPA study

BACKGROUND

Streptococcus pneumoniae serotypes distribution in community-acquired pneumonia (CAP) requiring hospitalization in adults after introduction of PCV13 in children is not well known. Our aim was to evaluate the distribution of serotypes in pneumococcal pneumonia according to risk factors and comorbidity conditions after the introduction of PCV13 in children in 2010.

METHODS

A prospective study from 2011 to 2014 was performed in immunocompetent adults hospitalized with CAP in 3 Spanish hospitals. Microbiological confirmation was obtained using a serotype specific urinary antigen detection test (UAD test), Binax Now and conventional cultures.

RESULTS

1258 adults were enrolled and pneumococcal pneumonia (invasive disease in 17.7%) was confirmed in 368 (29.3%) and 17.6% of the any-cause CAP were caused by PVC13 serotypes (3.5% PCV7 serotypes). Around 60% of pneumococcal CAP were caused by PCV13 serotypes (74.6% in invasive episodes vs 57.4% in non-invasive ones). The most prevalent serotypes in invasive disease were 1, 3, 7F, 19A and 14. No significant differences were observed in the distribution of PCV13 serotypes across the study periods. Regarding comorbidity, the rate of PCV13 serotypes was similar among them, and it was slightly higher in those with no underlying conditions.

CONCLUSIONS

Serotypes included in PCV13 caused a significant proportion of CAP in adults with underlying conditions and in healthy adults, with no significant changes in cases due to PCV7 or PCV13 from 2011 to 2014, suggesting an insufficient indirect protection from childhood vaccination. Strategies for implementing pneumococcal vaccination of adults are encouraged to reduce the incidence of pneumococcal episodes.

Pneumonia and Streptococcus pneumoniae vaccine

Pneumonia is an inflammatory disease of the lung, responsible for high morbidity and mortality worldwide. It is caused by bacteria, viruses, fungi, or other microorganisms. Streptococcus pneumoniae, a gram-positive bacterium with over 90 serotypes, is the most common causative agent. Moreover, comorbid factors including heart failure, renal disease, and pulmonary disease could increase the risk of pneumococcal pneumonia. Since the advent of the pneumococcal vaccine in the 1980s, the incidence of pneumonia has decreased significantly. However, current vaccines confer only limited protection against serotypes included in the vaccine. Thus, to overcome this limitation, new types of pneumococcal vaccines have been sought and under clinical trials. In this review, we discuss pneumonia and summarize the various types of pneumococcal vaccines in progress.

Serotypes and antibiotic susceptibility of Streptococcus pneumoniae isolated from hospitalized patients with community-acquired pneumonia in Italy

Background:

Pneumonia remain an important public health problem. The primary objective was to determine the proportion of community-acquired pneumonia that is attributable to Streptococcus pneumoniae infection; secondary objectives were the description of community-acquired pneumonia attributable to Streptococcus pneumoniae according to socio-demographic and clinical variables, the clinical evolution of community-acquired pneumonia and the description of the serotype distribution of vaccine-preventable disease and antibiotic resistance rate of pneumococcal infections.

Methods:

An observational, prospective study was conducted on consecutive patients coming from the community, who were hospitalized with pneumonia. Data on admission, at discharge and 30 days after discharge were collected. Logistic regression models were used to evaluate the risk factors independently associated with pneumococcal pneumonia.

Results:

Among the 193 patients enrolled in the study, the etiology of community-acquired pneumonia was identified in 60 patients (33%) and 35 (18%) of evaluable patients had community-acquired pneumonia due to Streptococcus pneumoniae. Of all clinical characteristics, if no previous antibiotic treatment was performed, there was a 13-fold higher risk of presenting community-acquired pneumonia due to Streptococcus pneumoniae (odds ratio, 12.9; 95% confidence interval, 1.42–117.9). Moreover, the most frequent isolated serotypes were 35F, 3 and 24 (29%, 23% and 16%, respectively).

Conclusion:

The most frequent serotypes in pneumococcal community-acquired pneumonia are 35F, 3, 24, 6 and 7A, and thus almost 50% of Streptococcus pneumoniae strains could be covered by pneumococcal conjugate vaccine 13 in adult patients with risk factors for pneumococcal infections.

Pneumococcal conjugate vaccine use in adults - Addressing an unmet medical need for non-bacteremic pneumococcal pneumonia

Streptococcus pneumoniae is a frequent cause of community acquired pneumonia (CAP), with the largest burden of disease attributed to non-bacteremic pneumonia. Due to the high persistent burden of disease, pneumococcal pneumonia, particularly non-bacteremic pneumococcal pneumonia, continues to be a major public health concern. There are currently two pneumococcal vaccines approved for use in adults in the United States (US) and other countries worldwide: a 23-valent pneumococcal simple polysaccharide vaccine (PPV23), and a 13-valent pneumococcal conjugate vaccine (PCV13). The capsular polysaccharides included in PPV23 induce antibodies primarily by a T-cell independent mechanism, thus the immune response is short lived and lacks the ability to elicit an anamnestic response. PCV13, on the other hand, has the bacterial polysaccharides covalently conjugated to an immunogenic carrier protein resulting in the formation of memory B lymphocytes, thus proving long-acting immunologic memory and an anamnestic response. Despite 30years of use, the question of PPV23 vaccine efficacy, particularly with respect to efficacy for non-bacteremic pneumonia, has been extensively debated and investigated; whereas PCV13 efficacy against vaccine-type pneumococcal CAP, both bacteremic and non-bacteremic, was confirmed in a large randomized controlled trial in older adults. PCV13 was approved under the US Food and Drug Administration's accelerated pathway, which allows for earlier approval of products that provide meaningful benefit over existing treatments - in this case, protection of adults from non-bacteremic pneumococcal pneumonia. Its use is now increasingly recommended globally. This article summarizes the history and use of PPV23 and PCV13 in adults and how vaccination of adults with PCV13 addresses an unmet medical need.

Penicillin treatment for patients with Community-Acquired Pneumonia in Denmark: a retrospective cohort study

BACKGROUND

Community-acquired pneumonia (CAP) is a severe infection, with high mortality. Antibiotic strategies for CAP differ across Europe. The objective of the study was to describe the epidemiology of CAP in Denmark and evaluate the prognosis of patients empirically treated with penicillin-G/V monotherapy.

METHODS

Retrospective cohort study including hospitalized patients with x-ray confirmed CAP. We calculated the population-based incidence, reviewed types of empiric antibiotics and duration of antibiotic treatment. We evaluated the association between mortality and treatment with empiric penicillin-G/V using logistic regression analysis.

RESULTS

We included 1320 patients. The incidence of hospitalized CAP was 3.1/1000 inhabitants. Median age was 71 years (IQR; 58-81) and in-hospital mortality was 8%. Median duration of antibiotic treatment was 10 days (IQR; 8-12). In total 45% were treated with penicillin-G/V as empiric monotherapy and they did not have a higher mortality compared to patients treated with broader-spectrum antibiotics (OR 0.92, CI 95% 0.55-1.53).

CONCLUSION

The duration of treatment exceeded recommendations in European guidelines. Empiric monotherapy with penicillin-G/V was commonly used and not associated with increased mortality in patients with mild to moderate pneumonia. Our results are in agreement with current conservative antibiotic strategy as outlined in the Danish guidelines.

Molecular epidemiology of pneumococcal isolates from children in China

Objectives:

To investigate the molecular epidemiology of pneumococcal isolates in Chongqing, China.

Methods:

In this cross-sectional study, 51 invasive Streptococcus pneumoniae (S. pneumoniae) strains were from children with invasive pneumococcal disease (IPD) and 32 carriage strains from healthy children from January 2010 to December 2013 at the Children’s Hospital of Chongqing Medical University, Chongqing, China. Multilocus sequence typing was used to identify the sequence types (STs). Capsular serotypes were determined by multiplex polymerase chain reaction. Drug susceptibility and resistance was determined by minimum inhibitory concentrations.

Results:

In this study, 11 serotypes were identified among the 83 S. pneumoniae clinical isolates tested. Prevalent serotypes were 19A (20.4%), 6A/B (20.4%), 19F (15.7%), 14 (14.5%), and 23F (10.8%). Serotype 19F was the most frequent carriage strain, and serotype 19A was the most frequent invasive strain. The ST983 was the most prevalent ST for carriage strains, and ST320 was the most prevalent ST for invasive strains. For gene analysis, psaA (99.5%) and piaA (98.6%) were present and much conserved in all pneumococci tested. The cps2A and pcsB genes were more frequent in invasive isolates than carriage strains. Antimicrobial resistance rates of invasive pneumococcal isolates to erythromycin, penicillin, meropenem, cefotaxime, and clindamycin were higher than the carriage isolates from children.

Conclusion:

Our epidemiological evidence shows that 19A, 6A/B, 19F, 14, and 23F remain the most prevalent serotypes, which can be targeted by PCV13. Genotypes and drug resistance varied between carriage and invasive strains. The PsaA and PiaA may be good protein vaccine candidates.

Community-acquired pneumonia in adults: Highlighting missed opportunities for vaccination

Pneumococcal pneumonia remains a clear unmet medical need for adults worldwide. Despite advances in vaccine technology, vaccination coverage remains low, putting many people at risk of significant morbidity and mortality. The herd effect seen with paediatric vaccination is not enough to protect all older and vulnerable people in the community, and more needs to be done to increase the uptake of pneumococcal vaccination in adults. Several key groups are at increased risk of contracting pneumococcal pneumonia, and eligible patients are being missed in clinical practice. At present, community-acquired pneumonia costs over €10 billion annually in Europe alone. Pneumococcal conjugate vaccination could translate into preventing 200,000 cases of community-acquired pneumonia every year in Europe alone. This group calls on governments and decision makers to implement consistent age-based vaccination strategies, and for healthcare professionals in daily clinical practice to identify eligible patients who would benefit from vaccination strategies.

Economic studies applied to vaccines against invasive diseases: An updated budget impact analysis of age-based pneumococcal vaccination strategies in the elderly in Italy

Many evaluations have been performed on the economic impact of pneumococcal vaccination in older adults (>64 y of age) in several countries, including Italy. However, these studies did not include the new data on the effectiveness of 13-valent conjugate pneumococcal vaccine (PCV13) in the elderly reported by the CAPiTA Study. The aim of the present study was to update our previous budget impact analysis of multi-cohort PCV13 vaccination in adults in Italy by including new scientific evidence. We also compared single-cohort vaccination strategies per year, in order to identify the cohort with the most favorable economic profile, in the event of the multi-cohort approach not being economically sustainable for the National Health System (NHS). The new impact analysis highlights that the vaccination of one, two or three adult cohorts per year in Italy would lead to a considerable reduction in pneumococcal disease and its related costs over 5 y. The strategies proved cost-effective (ICERs ranging from €14,605 to €15,412/QALY), i.e. well below the threshold of €50,000/QALY. The ICERs were slightly lower than those calculated in the first published analysis and vaccination continued to be economically favorable. In the case of a mono-cohort strategy, the vaccination of 65-year-old subjects, albeit more expensive, proved to be more favorable than the vaccination of 70- or 75-year-old cohorts. Finally, after the inclusion of the recent clinical evidence, the age-based PCV13 vaccination of the elderly in Italy continued to be economically justified from the NHS perspective in the short period. Vaccination of the elderly should therefore be strongly recommended nationwide in Italy.

Influence of HLA-DR polymorphism and allergic sensitization on humoral immune responses to intact pneumococcus in a transgenic mouse model

Asthma is independently associated with HLA-DR3 and increased risks of pneumococcal diseases. We aimed to determine whether HLA-DR polymorphism (HLA-DRB1*03), sensitization to house dust mite (HDM), or their interaction affects humoral immune responses to pneumococcal polysaccharide and protein antigens of intact pneumococci. Induction of serum titers of anti-pneumococcal polysaccharide and anti-surface protein IgM and IgG in response to immunization with intact pneumococci (Pn) serotype 14 was determined using humanized HLA-DR3 and DR2 transgenic mice. Transgenic mice were sensitized by injecting HDM and challenged with intranasal HDM. Mice were subsequently immunized with heat-killed Pn14 at day 24. Serum titers of anti-phosphorylcholine (PC) IgM and IgG, anti-pneumococcal polysaccharide, capsular type 14 (PPS14) IgM and IgG, and anti-pneumococcal surface protein A (PspA) IgG were measured. We included a total of 44 mice (22 DR3 and 22 DR2 mice) and half of mice in each group were sensitized with HDM (i.e. 22 HDM-sensitized and 22 control mice). HDM-sensitized mice, irrespective of HLA-DR polymorphism, had significantly lower humoral immune responses. HLA-DR3 mice, irrespective of HDM sensitization, elicited a significantly lower anti-PC IgG response. In contrast, the anti-PspA IgG response was higher in DR3 relative to DR2 mice. The effect of HDM sensitization on lowering humoral immune responses to Pn14 was observed in DR3 mice regardless of the nature of the antigen, whereas such decreases were observed only for the anti-PPS14 IgG and anti-PC IgM responses in DR2 mice. HDM sensitization lowered humoral immune responses to intact pneumococcus and this effect was significantly modified by the HLA-DR polymorphism.

A large two-centre study in to rates of influenza and pneumococcal vaccination and infection burden in rheumatoid arthritis in the UK

BACKGROUND

Infections are a common complication of RA with associated morbidity and mortality. The aetiology of increased risk is complex and multifactorial. Despite this, strategies to mitigate against risk of infection including vaccination are not always addressed in primary or secondary care with wide variation in practice from multiple small single centre audits. This study was a large two-centre survey of vaccine uptake in routine clinical practice and evaluated the relationship between vaccination and the burden of infection in RA patients.

METHODS

A patient questionnaire was devised and disseminated through postal, clinic and phone survey at 2 UK rheumatology centres, detailing past vaccination history, reasons for non-vaccination, and history of recent infection. In a subset of patients, primary care vaccination data were also obtained.

RESULTS

In total 929 patients responded to the survey. Over 85 % of patients were vaccinated against influenza, however only 44 % were vaccinated against pneumococcus. The vast majority of vaccination was undertaken in primary care. In the 12 months prior to the survey, 7.7 % of subjects recalled at least one episode of severe infection requiring admission, and nearly 40 % reported receiving at least one course of antibiotics.

CONCLUSIONS

Infections are common in RA and Rheumatologists need to be adept at recognising at risk patients and managing them appropriately. Influenza vaccination uptake is good whilst pneumococcal vaccination rates are comparatively poor. Collaborative approaches between primary and secondary care are required to maximise vaccine uptake, which is safe and recommended in RA patients.

Pneumococcus and the Elderly in Italy: A Summary of Available Evidence Regarding Carriage, Clinical Burden of Lower Respiratory Tract Infections and On-Field Effectiveness of PCV13 Vaccination

Streptococcus pneumoniae is currently the leading cause of community-acquired pneumonia (CAP) and lower respiratory tract infections (LRTI) in adults, elderly and high-risk subjects worldwide. The clear benefits of pneumococcal conjugate vaccination in childhood have been accompanied by a decrease of vaccine-serotype invasive diseases among adults in several countries, mainly due to the herd effect mediated by the reduction of vaccine-serotype nasopharyngeal colonization in both age groups, but this reduction in the incidence of pneumonia has not been observed. The "Community Acquired Pneumonia Immunization Trial in Adults" (CAPITA) study provided conclusive evidence about 13-valent pneumococcal conjugate vaccine (PCV13) efficacy in preventing CAP in adults and led Western countries to issue new recommendations for pneumococcal immunization targeting subjects >50 years and high-risk groups, with marked differences with respect to age and/or risk groups immunized, eligibility for reimbursement and national, regional or local implementation. Several Italian regions implemented PCV13 immunization programs in adults and interesting data have been come available in the last years, especially from Liguria, a Northern region with a high and long-lasting pneumococcal vaccine immunological pressure in infants. In this review, currently available evidence from Italy and Liguria regarding pneumococcal carriage, burden of CAP and LRTI, and on-field effectiveness of PCV13 immunization in adults and elderly will be summarized.

Prevention of adult pneumococcal pneumonia with the 13-valent pneumococcal conjugate vaccine: CAPiTA, the community-acquired pneumonia immunization trial in adults

The aging of the world population is expected to be accompanied by increased pneumococcal pneumonia in older adults. To address this, the Community-Acquired Pneumonia immunization Trial in Adults (CAPiTA), a large, randomized, placebo-controlled trial conducted to assess the 13-valent pneumococcal conjugate vaccine (PCV13) in adults ≥65 years, found statistically significant vaccine efficacy for first episodes of vaccine-type community-acquired pneumonia (VT-CAP; 46%), nonbacteremic/noninvasive VT-CAP (45%), and VT invasive pneumococcal disease (75%), along with an acceptable safety profile. Study results were presented to the US Advisory Committee on Immunization Practices in June 2014, which subsequently recommended sequential PCV13 and 23-valent pneumococcal polysaccharide vaccination for adults ≥65 years. Thus, appropriate protection of adults at risk for pneumococcal CAP will include vaccination with PCV13.

Pneumococcal conjugate vaccine use in adults

Streptococcus pneumoniae is a leading cause of illness and death in adults. A polysaccharide vaccine has been available for over 30 years, but despite significant use, the public health impact of this vaccine has been limited. The 13-valent pneumococcal conjugate vaccine (PCV13) has been licensed by the US Food and Drug Administration and other international regulatory authorities with the assumption that induction of a T cell-dependent immune response and noninferior immunogenicity to vaccine antigens when compared with the polysaccharide vaccine would be important to satisfy a significant unmet medical need. PCV13 efficacy against vaccine-type pneumococcal community-acquired pneumonia was confirmed in a large randomized controlled trial in older adults and its use is now increasingly recommended globally.

Pneumococcal Disease Prevention Among Adults: Strategies for the Use of Pneumococcal Vaccines

Use of the pneumococcal conjugate vaccines among children in the U.S. since 2000 has dramatically reduced pneumococcal disease burden among adults. Significant vaccine-preventable morbidity and mortality from pneumococcal infections still remains, especially among older adults. The U.S. Advisory Committee on Immunization Practices (ACIP) has recently recommended the routine use of both pneumococcal conjugate (PCV13) and polysaccharide vaccines (PPSV23) for adults ≥65 years. These recommendations were based on the remaining burden of illness among adults and the importance of non-bacteremic pneumonia prevention in light of new evidence confirming the efficacy of PCV13 to prevent pneumococcal pneumonia among older adults. This paper reviews the evidence that led ACIP to make recommendations for PCV13 and PPSV23 use among adults, and highlights potential gaps to be addressed by future studies to inform adult vaccination policy. The changing epidemiology of invasive pneumococcal disease and pneumonia should be closely monitored to evaluate the effectiveness and continued utility of the current vaccination strategy, and to identify future directions for pneumococcal disease prevention among older adults.

Association of serotype with respiratory presentations of pneumococcal infection, Ontario, Canada, 2003-2011

BACKGROUND

Pneumococcal disease burden is difficult to quantify due to limited data regarding non-bacteremic disease. We assessed serotype-specific differences in pneumococcal disease presentations in adults in Toronto, Canada.

METHODS

From 2003 to 2011, population-based surveillance for invasive pneumococcal disease was conducted and respiratory pneumococcal isolates collected in Metropolitan Toronto/Peel Region, Canada. Episodes of care were classified into disease categories.

RESULTS

Of 3105 eligible cases of IPD, 2060 cases were bacteremic pneumonia, and 1045 bacteremia without pneumonia. Of 2751 eligible respiratory cases, 1542 (56.0%) were non-bacteremic pneumonia (NBPP), 467 (17.0%) were other acute respiratory infection (oARI), and 742 (27.0%) were isolates representing colonization. Serotypes 3 (11.3%), 19A (8.4%) and 22F (6.2%) were the most common; serotypes 1,5, and 8 were rare. Serotypes 4, 14, 7F, 9V, 12F, 14, 19A and 6C were over-represented in bacteremic disease, and serotypes 3, 6A, 11A, 19F, 23A, 23F, 35B, 35F were more common in NBPP. The proportion of cases due to PCV7 serotypes declined from 48.7% to 8.7% in bacteremic pneumonia, from 35.3% to 10.9% in NBPP, from 34.2% to 7.5% in oARI, and from 38.7% to 12.2% in colonizing isolates. In 2010-2011, PCV13 serotypes accounted for 62.6% of isolates associated with bacteremic pneumonia, 42.0% of bacteremia without pneumonia, 41.1% of NBPP, 25.7% of oARI, and 32.9% of colonizing isolates.

CONCLUSIONS

Serotype distributions differ significantly in different presentations of pneumococcal disease. Herd protection due to PCV7 has changed serotype distribution, but PCV13 serotypes remain important in all categories of disease.

Incidence of Hospitalized Pneumococcal Pneumonia among Adults in Guatemala, 2008-2012

Background

Streptococcus pneumoniae is a leading cause of pneumonia worldwide. However, the burden of pneumococcal pneumonia among adults in low- and middle-income countries is not well described.

Methods

Data from 2008–2012 was analyzed from two surveillance sites in Guatemala to describe the incidence of pneumococcal pneumonia in adults. A case of hospitalized pneumococcal pneumonia was defined as a positive pneumococcal urinary antigen test or blood culture in persons aged ≥ 18 years hospitalized with an acute respiratory infection (ARI).

Results

Among 1595 adults admitted with ARI, 1363 (82%) had either urine testing (n = 1286) or blood culture (n = 338) performed. Of these, 188 (14%) had pneumococcal pneumonia, including 173 detected by urine only, 8 by blood culture only, and 7 by both methods. Incidence rates increased with age, with the lowest rate among 18–24 year-olds (2.75/100,000) and the highest among ≥65 year-olds (31.3/100,000). The adjusted incidence of hospitalized pneumococcal pneumonia was 18.6/100,000 overall, with in-hospital mortality of 5%.

Conclusions

An important burden of hospitalized pneumococcal pneumonia in adults was described, particularly for the elderly. However, even adjusted rates likely underestimate the true burden of pneumococcal pneumonia in the community. These data provide a baseline against which to measure the indirect effects of the 2013 introduction of the pneumococcal conjugate vaccine in children in Guatemala.

Isolation site influences virulence phenotype of serotype 14 Streptococcus pneumoniae strains belonging to multilocus sequence type 15

Streptococcus pneumoniae is a diverse species causing invasive as well as localized infections that result in massive global morbidity and mortality. Strains vary markedly in pathogenic potential, but the molecular basis is obscured by the diversity and plasticity of the pneumococcal genome. We have previously reported that S. pneumoniae serotype 3 isolates belonging to the same multilocus sequence type (MLST) differed markedly in in vitro and in vivo phenotypes, in accordance with the clinical site of isolation, suggesting stable niche adaptation within a clonal lineage. In the present study, we have extended our analysis to serotype 14 clinical isolates from cases of sepsis or otitis media that belong to the same MLST (ST15). In a murine intranasal challenge model, five ST15 isolates (three from blood and two from ears) colonized the nasopharynx to similar extents. However, blood and ear isolates exhibited significant differences in bacterial loads in other host niches (lungs, ear, and brain) at both 24 and 72 h postchallenge. In spite of these differences, blood and ear isolates were present in the lungs at similar levels at 6 h postchallenge, suggesting that early immune responses may underpin the distinct virulence phenotypes. Transcriptional analysis of lung tissue from mice infected for 6 h with blood isolates versus ear isolates revealed 8 differentially expressed genes. Two of these were exclusively expressed in response to infection with the ear isolate. These results suggest a link between the differential capacities to elicit early innate immune responses and the distinct virulence phenotypes of clonally related S. pneumoniae strains.

Noninvasive Streptococcus pneumoniae serotypes recovered from hospitalized adult patients in the United States in 2009 to 2012

This study was conducted to determine the serotype distribution and trends over time of Streptococcus pneumoniae strains associated with noninvasive infections among adult patients ≥18 years of age in the United States (2009 to 2012). A total of 2,927 S. pneumoniae isolates recovered from patients presenting with respiratory infections and obtained mainly (87.0%) from lower respiratory tract specimens (sputum) were included. The levels of the 7-valent pneumococcal conjugate vaccine (PCV7) serotypes remained stable over the 4-year study period (4.6% to 5.5%; P = 0.953). Overall, 13-valent pneumococcal conjugate vaccine (PCV13) serotypes were identified in 32.7% of samples, declining from 33.7% to 35.5% in 2009 to 2011 to 28.2% in 2012 (P = 0.007), with a significant decrease in the levels of serotypes 7F (P = 0.013) and 6A (P = 0.010). The levels of 19A remained constant (15.8% to 17.1%) during 2009 to 2011, dropping to 12.2% in 2012 (P = 0.089). The prevalence of serotypes associated with the 23-valent pneumococcal polysaccharide vaccine (PPSV23), but not PCV13, remained generally stable; however, the prevalence of serotypes 15B and 15C (15B/15C) increased from 2.7% to 6.3% (P = 0.010). The proportion of nonvaccine serotypes increased gradually during the study period (P = 0.044), particularly for serotype 35B (from 3.6% in 2009 to 8.2% in 2012; P = 0.001). Nonsusceptibility rates for penicillin (susceptible breakpoint, ≤2 μg/ml) and clindamycin against PCV7 serotypes decreased over the period. These results suggest the emergence of indirect effects following introduction of PCV13 for infants and young children; continued surveillance is needed to assess the burden of PCV13 serotypes in the adult population after the implementation of age-based recommendations in the United States.