The effect of underlying clinical conditions on the risk of developing invasive pneumococcal disease in England

Prevalence of high, medium and low-risk medical conditions for pneumococcal vaccination in Catalonian middle-aged and older adults: a population-based study

BACKGROUND

Updated population-based data on the frequency and distribution of risk factors for pneumococcal disease is scarce. This study investigated the prevalence of distinct comorbidities and underlying risk conditions related to an increasing risk of pneumococcal disease among Catalonian middle-aged and older adults.

METHODS

Cross-sectional population-based study including 2,033,465 individuals aged 50 years or older registered at 01/01/2015 in the Catalonian Health Institute (Catalonia, Spain). The clinical research database of the Information System for the Development of Research in Primary Care (SIDIAP database) was used to identify high-risk (asplenia and/or immunocompromising conditions) and other increased-risk conditions (chronic pulmonary, cardiac or liver disease, diabetes mellitus, alcoholism and/or smoking) among study subjects.

RESULTS

Globally, 980,310 (48.2%) of the 2,033,465 study population had at least one risk condition of suffering pneumococcal disease (55.4% in men vs 42.0% in women, p < 0.001; 41.7% in people 50-64 years vs 54.7% in persons 65 years or older, p < 0.001). An amount of 176,600 individuals (8.7%) had high-risk conditions (basically immunocompromising conditions). On the other hand, 803,710 persons (39.5%) had one or more other risk conditions. In fact, 212,255 (10.4%) had chronic pulmonary diseases, 248,377 (12.2%) cardiac disease, 41,734 (2.1%) liver disease, 341,535 (16.8%) diabetes mellitus, 58,781 (2.9%) alcoholism and 317,558 (15.6%) were smokers.

CONCLUSION

In our setting, approximately 50 % of overall persons 50 years or older may be considered at-risk population for pneumococcal disease (almost 10 % have high-risk conditions and 40 % have other risk conditions).

Immune response to pneumococcal conjugate vaccine in patients with systemic vasculitis receiving standard of care therapy

AIM

To study the effect of standard of care therapy on antibody response and functionality following immunization with 13-valent pneumococcal conjugate vaccine (PCV13) in patients with primary systemic vasculitis compared to healthy controls.

METHODS

49 patients with vasculitis and 49 controls received a single dose (0.5ml) PCV13 intramuscularly. Ongoing treatments: azathioprine (AZA; n=11), cyclophosphamide (CYC; n=6), methotrexate (MTX; n=9), rituximab (n=3); anti-TNF (n=2), mycophenolate mofetil (n=2), prednisolone alone (n=15) and no active treatment (n=2). Specific antibody concentrations for serotypes 6B and 23F were determined using ELISA and opsonophagocytic activity (OPA) assay (23F) was performed, on serum samples taken immediately before and 4-6weeks after vaccination. Proportion of individuals with putative protective antibody concentration (≥1.0µg/mL) and positive antibody response (≥2-fold increase from prevaccination concentration) for both serotypes were calculated and groups were compared.

RESULTS

At baseline, 6 patients (12%) and 12 controls (24%) had protective antibody levels for both serotypes. After vaccination, antibodies increased for both serotypes in patients and controls (p<0.001), 32 patients (65%) and 35 controls (71%) reached protective level for 6B, and 32 patients (65%) and 37 controls (76%) for 23F. Compared to controls, patients had lower prevaccination geometric mean concentration (23F, p=0.01) and a numerical trend towards lower prevaccination level (6B) and postvaccination levels (both serotypes). Patients with prednisolone alone had lower prevaccination OPA (p<0.01) compared to controls. OPA increased after vaccination in both patients and controls (p<0.001), but improvement was better in controls (p=0.001). AZA, CYC or MTX, but not prednisolone alone, tended towards a lower proportion of patients reaching protective antibody levels (p=0.06), compared to controls.

CONCLUSIONS

Pneumococcal conjugate vaccine was safe and immunogenic in patients with established vasculitis. Treatment with DMARDs, mostly AZA, CYC and MTX but not systemic prednisolone may impair antibody response.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02240888. Registered 4 September, 2014.

Discrepant serological assays for Pneumococcus in renal transplant recipients - a prospective study

Vaccine immunoprotection for Streptococcus pneumoniae is mediated by opsonizing antibodies targeting serotype-specific capsular polysaccharides. Quantitative antibody levels enzyme-linked immunosorbent assay (ELISA) and antibody-mediated opsonophagocytic assays (OPA) measure vaccine-induced protection; correlation of these assays in transplantation requires investigation. This study examines the laboratory assessment of antibody titers in vaccinated renal recipients. Streptococcus pneumoniae 19A is common in immunocompromised hosts and is represented in protein-conjugate vaccines (PCV) and polysaccharide vaccines (PSV). Antibodies to 19A in serial sera from 30 vaccinated renal transplant recipients were compared using ELISA and OPA assays. Subject titers were classified as protected or not by ELISA (>0.35 μg/ml) and OPA titer (>1:8). Antibody titers analyzed using McNemar's test indicate that protection measured by the two assays are not the same (P = 0.0078); simple linear regression of within-subject geometric means of 19A enzyme-linked immunosorbent assay (ELISA) antibody levels versus 19A opsonophagocytic assays (OPA) titers demonstrates significant correlation between the two assays (P < 0.001). Vaccination is increasingly important given increasing antimicrobial resistance worldwide. OPA and ELISA antibody assays do not correlate well using current values for protective immunity against the Pneumococcus in immunosuppressed transplant recipients. Future studies of vaccination in transplant recipients should evaluate protective antibody levels using both functional antibody assays and standard ELISA antibody titers. (ClinicalTrials.gov: NCT00307125).

Modeling the cost-effectiveness of infant vaccination with pneumococcal conjugate vaccines in Germany

BACKGROUND

In 2009, the European Medicines Agency granted approval for two higher-valent pneumococcal conjugate vaccines. This study aims to evaluate the cost-effectiveness of universal infant (<2 years old) vaccination with a 13-valent pneumococcal conjugate vaccine (PCV13) in comparison with a 10-valent pneumococcal conjugate vaccine (PCV10) for the prevention of pneumococcal disease in Germany.

METHODS

A population-based Markov model was developed to estimate the impact of PCV13 and PCV10 on invasive pneumococcal disease (IPD), non-invasive pneumonia (PNE), and acute otitis media (AOM) over a time horizon of 50 years. The model included the effects of the historical vaccination scheme in infants as well as indirect herd effects and replacement disease. We used German epidemiological data to calculate episodes of IPD, PNE, and AOM, as well as direct and indirect effects of the vaccination. Parameter uncertainty was tested in univariate and probabilistic sensitivity analyses.

RESULTS

In the base-case analysis, the ICER of PCV13 versus PCV10 infant vaccination was EUR 9826 per quality-adjusted life-year (QALY) gained or EUR 5490 per life-year (LY) gained from the societal perspective and EUR 3368 per QALY gained or EUR 1882 per LY gained from the perspective of the German statutory health insurance. The results were particularly sensitive to the magnitude of indirect effects of both vaccines.

CONCLUSIONS

Universal infant vaccination with PCV13 is likely to be a cost-effective intervention compared with PCV10 within the German health care system, if additional net indirect effects of PCV13 vaccination are significant.

Long-term mortality after IPD and bacteremic versus non-bacteremic pneumococcal pneumonia

BACKGROUND

Short-term mortality after invasive pneumococcal disease (IPD) and pneumococcal pneumonia is high but data on long-term mortality (including the comparison between bacteremic and non-invasive/non-bacteremic pneumococcal pneumonia) within the first years after diagnosis are scarce.

METHODS

Adult patients with 'non-pneumonia' IPD and 'invasive pneumonia' (from 2004 to 2012) and with 'bacteremic' vs 'non-invasive/non-bacteremic (NI/NB)' pneumococcal pneumonia (from 2008 to 2012) diagnosed by negative blood culture but a positive urinary antigen test (UAT) were identified in a Dutch hospital. Mortality of patients up to 10years after diagnosis was compared with age- and sex-matched life-expectancy data of the general population. Multivariable Cox regression analysis was used to study predictors for mortality in invasive pneumonia patients and to adjust for confounders comparing mortality between bacteremic and NI/NB/UAT-positive pneumonia patients.

RESULTS

Of 228 invasive pneumonia patients 17% died within 30days and in 30-day survivors cumulative long-term mortality at 1 and 5years were 16% and 39% as compared with 3% and 15% in age- and sex-matched persons. High mortality was largely dependent on pre-existent comorbidities. In invasive pneumonia patients who survived the first 30days, age, male gender, chronic cardiovascular disease, malignancy and PCV7 serotype disease were independent predictors for higher long-term mortality. For bacteremic pneumonia patients (n=128) 30-day mortality was 16% and almost similar to 14% in NI/NB/UAT-positive pneumococcal pneumonia patients (n=170). In 30-day survivors of bacteremic pneumonia (n=108, median age 66years), cumulative mortality at 1 and 3years were 13% and 29% as compared with 18% and 40% in NI/NB/UAT-positive pneumococcal pneumonia patients (n=146, median age 67years) without a significant difference in mortality.

CONCLUSIONS

Approximately 40% of all patients, who survived the first 30days after presentation with non-pneumonia IPD and pneumococcal pneumonia died within the following 5years. High long-term mortality was largely dependent on pre-existent comorbidity.

Coeliac disease and invasive pneumococcal disease: a population-based cohort study

Severe infections are recognized complications of coeliac disease (CD). In the present study we aimed to examine whether individuals with CD are at increased risk of invasive pneumococcal disease (IPD). To do so, we performed a population-based cohort study including 29 012 individuals with biopsy-proven CD identified through biopsy reports from all pathology departments in Sweden. Each individual with CD was matched with up to five controls (n = 144 257). IPD events were identified through regional and national microbiological databases, including the National Surveillance System for Infectious Diseases. We used Cox regression analyses to estimate hazard ratios (HRs) for diagnosed IPD. A total of 207 individuals had a record of IPD whereas 45/29 012 had CD (0·15%) and 162/144 257 were controls (0·11%). This corresponded to a 46% increased risk for IPD [HR 1·46, 95% confidence interval (CI) 1·05–2·03]. The risk estimate was similar after adjustment for socioeconomic status, educational level and comorbidities, but then failed to attain statistical significance (adjusted HR 1·40, 95% CI 0·99–1·97). Nonetheless, our study shows a trend towards an increased risk for IPD in CD patients. The findings support results seen in earlier research and taking that into consideration individuals with CD may be considered for pneumococcal vaccination.

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.

Streptococcus pneumoniae pharyngeal colonization in school-age children and adolescents with cancer

Patients with cancer, particularly those with hematologic malignancies, are at an increased risk of invasive pneumococcal disease (IPD) and they are included in the list of subjects for whom pneumococcal vaccination is recommended. The main aim of this study was to evaluate Streptococcus pneumoniae colonization in school-aged children and adolescents with cancer to determine the potential protective efficacy of 13-valent pneumococcal conjugate vaccine (PCV13). An oropharyngeal swab was obtained from 277 patients (age range 6-17 years) with cancer during routine clinical visits and analyzed for S. pneumoniae using real-time polymerase chain reaction. S. pneumoniae was identified in 52 patients (18.8%), including 47/235 (20.0%) with hematologic malignancies and 5/42 (11.9%) with solid tumors. Colonization declined significantly with an increase in age (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.16-0.71, and OR 0.30, 95% CI 0.11-0.82 in children aged 10-14 and ≥15 years, respectively, as compared to those <10 years). Carriage was more common among patients with leukemia or lymphoma than in children with solid tumors. Co-trimoxazole prophylaxis was significantly associated with reduced pneumococcal carriage (OR 0.41, 95% CI 0.19-0.89). A total of 15/58 (25.9%) and 26/216 (12.0%) children were colonized by PCV13 serotypes among cancer patients previously vaccinated and not vaccinated with 7-valent pneumococcal conjugate vaccine (PCV7), respectively. In conclusion, this study indicates that children and adolescents with cancer are frequently colonized by S. pneumoniae. Because most of the carried serotypes are included in PCV13, this vaccine is presently the best solution to reduce the risk of IPD in these patients.

Pneumococcal vaccination

PURPOSE OF REVIEW

Pneumococcal diseases (invasive diseases, pneumonia, otitis media, and sinusitis) are among the most frequent preventable infectious diseases carrying a very high morbidity and case fatality rate worldwide. Pneumococcal vaccination is a key element to reduce the global burden of the disease in children and adult population. Our aim is to discuss current knowledge of the epidemiology of pneumococcal disease and pneumococcal vaccines.

RECENT FINDINGS

After the introduction of conjugate vaccines (PCV7 and PCV13), rates of pneumococcal diseases because of vaccine serotypes have decreased considerably among children in the vaccine target and among nonvaccinated children and adults. Results of the Community-Acquired Pneumonia Immunization Trial in Adults demonstrated 45.6% efficacy of PCV13 against the first episode of pneumonia, 45% against first-episode nonbacteremic pneumococcal pneumonia, and 75% against the first episode of invasive pneumococcal diseases in adults older than 65 years. Recommendations for pneumococcal vaccination have changed recently in both the United States and Europe.

SUMMARY

The changing epidemiology of pneumococcal diseases should be closely investigated to assess the effectiveness and the usefulness of the current vaccination policies, and to identify future directions for preventing pneumococcal infections.

Pneumococcal Disease in the Era of Pneumococcal Conjugate Vaccine

Universal immunization of infants and toddlers with pneumococcal conjugate vaccines over the last 15 years has dramatically altered the landscape of pneumococcal disease. Decreases in invasive pneumococcal disease, all-cause pneumonia, empyema, mastoiditis, acute otitis media, and complicated otitis media have been reported from multiple countries in which universal immunization has been implemented. Children with comorbid conditions have higher rates of pneumococcal disease and increased case fatality rates compared with otherwise healthy children, and protection for the most vulnerable pediatric patients will require new strategies to address the underlying host susceptibility and the expanded spectrum of serotypes observed.

Comparative impact of pneumococcal conjugate vaccines on pneumococcal meningitis according to underlying conditions

BACKGROUND

Several underlying conditions increase the risk of pneumococcal meningitis (PM) in childhood. Patients with these diseases are initially considered as an important target of pneumococcal conjugate vaccines (PCVs). Limited data are available for PM in children with underlying conditions. To understand the benefits of PCV7 followed by PCV13 in this vulnerable population, we analyzed the data for a large cohort of pediatric patients with PM in France from 2001 to 2014.

METHODS

We conducted hospital-based active surveillance with 227 pediatric wards working with 168 microbiology departments throughout France. Standardized inclusion criteria for PM were used and data were analyzed by a pre-PCV7, post-PCV7 and post-PCV13 period.

RESULTS

From 2001 to 2014, among the 1582 cases of PM, 62.5% were reported in children less than 2years old. Underlying conditions (n=255, 16.1%) accounted for 7.3% of the cases in these young children versus 30.8% for children ⩾2-18years old (p<0.001). After PCV13 implementation, PM cases decreased by 44.0% from 2009 to 2014, mainly in children without underlying conditions. Though the number of children with underlying conditions remained stable, their proportion among overall PM cases increased by 79.1%. Among children with underlying conditions, PCV7 serotypes, 6 additional PCV13 serotypes, additional 11 serotypes in PPV23 and other serotypes accounted for 24.5%, 14.7%, 25.0% and 35.8%, respectively (p<0.001). After PCV13 implementation, 50.0% of PM cases with underlying conditions and 37.9% without underlying conditions were caused by serotypes included in neither PCV13 nor PPV23.

CONCLUSION

Besides the reduced numbers of PM, its profile has changed, with an increase in cases in proportion of children with underlying conditions accompanied by a striking change in serotype distribution. This underlines the importance of detecting underlying conditions in children with PM in the PCV13 era.

Cost Effectiveness of the 13-Valent Pneumococcal Conjugate Vaccination Program in Chronic Obstructive Pulmonary Disease Patients Aged 50+ Years in Spain

Background

Patients with chronic obstructive pulmonary disease (COPD) are at elevated risk of pneumococcal infection. A 13-valent pneumococcal conjugate vaccine (PCV13) was approved for protection against invasive disease and pneumonia caused by Streptococcus pneumoniae in adults. This study estimated the incremental cost-effectiveness ratio (ICER) of vaccinating COPD patients ≥50 years old with PCV13 compared with current vaccination policy (CVP) with 23-valent pneumococcal polysaccharide vaccine.

Methods

A Markov model accounting for the risks and costs for all-cause non-bacteremic pneumonia (NBP) and invasive pneumococcal disease (IPD) was developed. All parameters, such as disease incidence and costs (€; 2015 values), were based on published data. The perspective of the analysis was that of the Spanish National Healthcare System, and the horizon of evaluation was lifetime in the base case. Vaccine effectiveness considered waning effect over time. Outcomes and costs were both discounted by 3 % annually.

Results

Over a lifetime horizon and for a 629,747 COPD total population, PCV13 would prevent 2224 cases of inpatient NBP, 3134 cases of outpatient NBP, and 210 IPD extra cases in comparison with CVP. Additionally, 398 related deaths would be averted. The ICER was €1518 per quality-adjusted life-year (QALY) gained for PCV13 versus CVP. PCV13 was found to be cost effective versus CVP from a 5-year modelling horizon (1302 inpatient NBP and 1835 outpatient NBP cases together with 182 deaths would be prevented [ICER €25,573/QALY]). Univariate and probabilistic sensitivity analyses confirmed the robustness of the model.

Conclusions

At the commonly accepted willingness-to-pay threshold of €30,000/QALY gained, PCV13 vaccination in COPD patients aged ≥50 years was a cost-effective strategy compared with CVP from 5 years to lifetime horizon in Spain.

Epidemiology of invasive pneumococcal infections: manifestations, incidence and case fatality rate correlated to age, gender and risk factors

Background

Incidence, manifestations and case-fatality rate (CFR) of invasive pneumococcal disease (IPD) vary with age and comorbidities. New vaccines, changing age distribution, prolonged survival among immunocompromised patients and improved sepsis management have created a need for an update of basic facts to inform vaccine recommendations.

Methods

Age, gender and comorbidities were related to manifestations and death for 2977 consecutive patients with IPD in a Swedish region with 1.5 million inhabitants during 13 years before introduction of pneumococcal conjugate vaccines (PCV) in the infant vaccination program. These data were related to population statistics and prevalence of several comorbidities, and compared with two previous studies giving a total follow-up of 45 years in the same area.

Results

The annual incidence was 15/100,000 for any IPD and 1.1/100,000 for meningitis; highest among elderly followed by children < 2 years. It was 2238/100,000 among myeloma patients, followed by chronic lymphatic leukemia, hemodialysis and lung cancer, but not elevated among asthma patients. CFR was 10 % among all patients, varying from 3 % below 18 years to 22 % ≥ 80 years. During 45 years, the IPD incidence increased threefold and CFR dropped from 20 to 10 %. Meningitis incidence remained stable (1.1/100,000/year) but CFR dropped from 33 to 13 %. IPD-specific mortality decreased among children <2 years from 3.1 to 0.46/100,000/year but tripled among those ≥65 years.

Conclusions

IPD incidence and CFR vary widely between age and risk groups and over time even without general infant vaccination. Knowledge about specific epidemiological characteristics is important for informing and evaluating vaccination policies.

Epidemiology and outcome of sepsis in adult patients with Streptococcus pneumoniae infection in a Norwegian county 1993-2011: an observational study

BACKGROUND

Invasive pneumococcal disease (IPD) is responsible for significant mortality and morbidity worldwide. There are however few longitudinal studies on the changes in case fatality rate of IPD in recent years. We carried out a prospective observational study of patients with IPD in Nord Trøndelag county in Norway from 1993 to 2011 to study the clinical variables and disease outcome. The main outcome was all-cause mortality after 30 and 90 days.

METHODS

Patients with positive blood cultures were registered prospectively by the microbiology laboratory and clinical variables were registered retrospectively from patients' hospital records. The severity of sepsis was assigned according to the 2001 International Sepsis Definition Conference criteria. The association between mortality and predictive factors was studied using a logistic regression model.

RESULTS

The total number of patients was 414 with mean age of 67 years and 53 % were male. Comorbidity was assessed by the Charlson Comorbidity Index (CCI). A CCI-score of 0 was registered in 144 patients (34.8 %), whereas 190 had a score of 1-2 (45.9 %) and 80 (19.3 %) had a score ≥3. 68.8 % of the patients received appropriate antibiotics within the first 6 h. The 30-day mortality risk increased by age and was 3-fold higher for patients aged ≥80 years (24.9, 95 % CI 16.4-33.4 %) compared to patients aged <70 (8.0, 95 % CI 3.5-12.4 %). 110 patients, (26.6 %) had severe sepsis and 37 (8.9 %) had septic shock. The 30 day all-cause mortality risk for those with sepsis without organ failure was 5.4 % (95 % CI 2.7-8.0 %), 20.2 % (95 % CI 13.5-27.4 %) for those with severe sepsis and 35.0 % (95 % CI 21.6-49.0 %) for those with septic shock. The mortality risk did not differ between the first and the second halves of the study period with a 30-day mortality risk of 13.5 % (95 % CI 7.9-19.2 %) for 1993-2002 versus 11.8 % (95 % CI 8.2-15.3 %) for 2003-2011.

CONCLUSION

IPD carries a high mortality despite early and appropriate antibiotics in most cases. We found no substantial decrease in case fatality rate during the study period of 18 years. Older age and higher severity of disease were important risk factors for death in IPD.

A systematic review of the burden of vaccine preventable pneumococcal disease in UK adults

Background

Invasive pneumococcal disease (IPD) and pneumococcal pneumonia are common and carry a significant morbidity and mortality. Current strategies to prevent pneumococcal disease are under review in the United Kingdom (UK). We conducted a systematic review to evaluate the burden of vaccine type adult pneumococcal disease specifically in the UK.

Methods

A systematic review conducted and reported according to MOOSE guidelines. Relevant studies from 1990 to 2015 were included. The primary outcome was the incidence of vaccine type pneumococcal disease, focussing on the pneumococcal polysaccharide vaccine (PPSV), the 13-valent conjugate vaccine (PCV13) and the 7-valent conjugate vaccine (PCV7).

Results

Data from surveillance in England and Wales from 2013/14 shows an incidence of 6.85 per 100,000 population across all adult age groups for IPD, and an incidence of 20.58 per 100,000 population in those aged >65 years. The corresponding incidences for PCV13 serotype IPD were 1.4 per 100,000 and 3.72 per 100,000. The most recent available data for community-acquired pneumonia (CAP) including non-invasive disease showed an incidence of 20.6 per 100,000 for adult pneumococcal CAP and 8.6 per 100,000 population for PCV13 serotype CAP. Both IPD and CAP data sources in the UK suggest an ongoing herd protection effect from childhood PCV13 vaccination causing a reduction in the proportion of cases caused by PCV13 serotypes in adults. Despite this, applying the incidence rates to UK population estimates suggests more than 4000 patients annually will be hospitalised with PCV13 serotype CAP and more than 900 will be affected by IPD, although with a trend for these numbers to decrease over time.

There was limited recent data on serotype distribution in high risk groups such as those with chronic respiratory or cardiac disease and no data available for vaccine type (VT) CAP managed in the community where there is likely to be a considerable unmeasured burden.

Conclusion

The most recent available data suggests that VT pneumococcal disease continues to have a high burden in UK adults despite the impact of childhood PCV13 vaccination. IPD estimates represent only a fraction of the total burden of pneumococcal disease.

Study registration

PROSPERO CRD42015025043

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0242-0) contains supplementary material, which is available to authorized users.

Influence of Childhood Pneumococcal Conjugate Vaccines on Invasive Pneumococcal Disease in Adults With Underlying Comorbidities in Calgary, Alberta (2000-2013)

BACKGROUND

Pneumococcal conjugate vaccine (PCV) was introduced into Alberta, Canada's routine childhood immunization programs in 2002 (7-valent [PCV7]) and 2010 (13-valent [PCV13]). We assessed the effect of these programs on the epidemiology of invasive pneumococcal disease (IPD) to determine if PCV-associated indirect protection was relatively reduced in adults with underlying comorbidities.

METHODS

Demographic and clinical data were collected by a prospective, population-based surveillance system in Calgary, Alberta, Canada, from January 2000 to December 2013. An indirect cohort study design was used to assess for changes in the proportion of IPD cases with underlying comorbidities.

RESULTS

There were 1598 overall and 1346 adult IPD cases from 1 January 2000 to 31 December 2013. Overall IPD incidence decreased 33% (age 0-5 months), 86% (6-23 months), 67% (2-4 years), 26% (5-17 years), 22% (18-64 years), 36% (65-84 years), and 42% (≥85 years) from the prevaccine (January 2000-July 2002) to the post-PCV13 (July 2010-December 2013) period. Over the same timeframe, PCV7 serotype disease incidence declined to ≤1 case per 100 000 persons in all age groups. Neither the proportion of adult cases with immunocompetent comorbidities (relative risk ratio [RRR], 0.93; 95% confidence interval [CI], .62-1.40) nor immunocompromising comorbidities (RRR, 0.99; 95% CI, .61-1.61) differed between the pre-PCV period and post-PCV era.

CONCLUSIONS

Childhood PCV programs have provided considerable benefit, with substantial declines in overall and vaccine-serotype IPD in vaccinated children and in unvaccinated persons. Conjugate vaccine-associated indirect protection for adults with comorbidities was similar to that for healthy adults.

Effectiveness of Pneumococcal Conjugate Vaccines of Different Valences Against Invasive Pneumococcal Disease Among Children in Taiwan: A Nationwide Study

BACKGROUND

For the scarcity of data, we investigated the vaccine effectiveness (VE) of the combined use of pneumococcal conjugate vaccines (PCVs) of different valences against invasive pneumococcal disease (IPD) in children.

METHODS

We conducted a matched case-control study using the national IPD surveillance database and the national vaccination registry. Four age-matched, gender-matched and neighborhood-matched controls were identified for each incident IPD case ≦5 years with disease onsets between October 2007 and December 2013. Conditional logistic regression was used to assess VE against all serotype and serotype 19A IPD.

RESULTS

In 523 cases (median age: 28.5 months; range: 2.0-69.4 months) and 2086 controls (28.7; 2.2-70.1), a similar VE against all-serotype IPD was found between PCV13 (76%; 61-85%) and combined 7-valent PCV (PCV7)/10-valent PCV (PCV10) plus PCV13 (78%; 56-89%). The VE for PCV7/PCV10 was slightly lower (48%; 32-60%). Regarding serotype 19A, a significantly reduced risk was observed for both PCV13 (82%; 63-91%) and combined PCV7/PCV10 plus PCV13 (87%; 61-96%). PCV7/PCV10 had only a borderline protective association (31%; 4-51%). For children receiving PCV13 alone, VE against all-serotype IPD did not differ between starting the dosing at ≥2 (78%; 56-89%) or <2 (74%; 51-87%) years of age. VE was 81% (69-88%) within 6 months of the last dose of PCV and 19% (95% CI: -21 to 45%) after 2 years.

CONCLUSIONS

PCVs are effective against IPD during immunization with either the same or with a mixed series, but protection might be differential over time.

Cost-Effectiveness of Vaccinating Immunocompetent ≥65 Year Olds with the 13-Valent Pneumococcal Conjugate Vaccine in England

BACKGROUND

Recently a large clinical trial showed that the use of 13-valent pneumococcal conjugate vaccine (PCV13) among immunocompetent individuals aged 65 years and over was safe and efficacious. The aim of this study was to assess the cost-effectiveness of vaccinating immunocompetent 65 year olds with PCV13 vaccine in England. England is a country with universal childhood pneumococcal conjugate vaccination programme in place (7-valent (PCV7) since 2006 and PCV13 since 2010), as well as a 23-valent pneumococcal polysaccharide (PPV23) vaccination programme targeting clinical risk-groups and those ≥65 years.

METHOD

A static cohort cost-effectiveness model was developed to follow a cohort of 65 year olds until death, which will be vaccinated in the autumn of 2016 with PCV13. Sensitivity analysis was performed to test the robustness of the results.

RESULTS

The childhood vaccination programme with PCV7 has induced herd protection among older unvaccinated age groups, with a resultant low residual disease burden caused by PCV7 vaccine types. We show similar herd protection effects for the 6 additional serotypes included in PCV13, and project a new low post-introduction equilibrium of vaccine-type disease in 2018/19. Applying these incidence projections for both invasive disease and community-acquired pneumonia (CAP), and using recent measures of vaccine efficacy against these endpoints for ≥65 year olds, we estimate that vaccination of a cohort of immunocompetent 65 year olds with PCV13 would directly prevent 26 cases of IPD, 69 cases of CAP and 15 deaths. The associated cost-effectiveness ratio is £257,771 per QALY gained (using list price of £49.10 per dose and £7.51 administration costs) and is therefore considered not cost-effective. To obtain a cost-effective programme the price per dose would need to be negative. The results were sensitive to disease incidence, waning vaccine protection and case fatality rate; despite this, the overall conclusion was robust.

CONCLUSIONS

Vaccinating immunocompetent individuals aged ≥65 years with PCV13 is efficacious. However the absolute incidence of vaccine-type disease will likely become very low due to wider benefits of the childhood PCV13 vaccination programme, such that a specific PCV13 vaccination programme targeting the immunocompetent elderly would not be cost-effective.

Risk of hospitalization due to pneumococcal disease in adults in Spain. The CORIENNE study

Pneumococcal disease causes a high burden of disease in adults, leading to high rates of hospitalization, especially in the elderly. All hospital discharges for pneumococcal disease and pneumococcal pneumonia among adults over 18 y of age reported in first diagnostic position in 2011 (January 1, 2011 through December 31, 2011) were obtained. A total of 10,861 hospital discharges due to pneumococcal disease were reported in adults in Spain in 2011 with an annual incidence of hospitalization of 0.285 (CI 95%: 0.280-0.291) per 1,000 population over 18 y old. Case-fatality rate was 8%. Estimated cost of these hospitalisations in 2011 was more than 57 million €. Pneumococcal pneumonia accounted for the 92% of the hospital discharges All the chronic condition studied: asplenia, chronic respiratory disease, chronic heart disease, chronic renal disease, Diabetes Mellitus and immunosuppression, increased the risk of hospitalization in patients with pneumococcal pneumonia, especially in those aged 18-64 y old. Case-fatality rate among adult patients hospitalized with at least one underlying condition was significantly higher than among patients without comorbidities. Our results identified asplenia, chronic respiratory disease, chronic heart disease, chronic renal disease, chronic liver disease, Diabetes Mellitus and immunosuppression as risk groups for hospitalization. Older adults, immunocompromised patients and immunocompetent patients with underlying conditions could benefit from vaccination.

Declining mortality from adult pneumococcal infections linked to children's vaccination

OBJECTIVE

To determine changes in mortality among adults with invasive pneumococcal disease (IPD) after introducing pneumococcal conjugate vaccines (PCVs) in children.

METHODS

An active surveillance of adults with culture-proven IPD in Barcelona. Serotype-specific mortality and rates of disease and death were analysed in three periods: baseline (1994-2001), PCV7 (2002-2009) and PCV13 (2010-2013).

RESULTS

Overall, IPD caused by PCV7 serotypes was associated with increased case fatality rate (24 percent). In patients 18-64 years (baseline vs. PCV7 vs. PCV13 periods), case fatality rate from IPD decreased (22 vs.14 vs. 12 percent), and it was associated with a decline in PCV7 serotypes (3.56 vs. 2.80 vs. 1.49 cases/10(5) person-years) and in PCV7 serotypes-specific death (0.74 vs. 0.53 vs. 0.09 deaths/10(5) person-years). In patients ≥65 years, case fatality rate did not change (24 vs. 22 vs. 24 percent); however, there was a decline in PCV7 serotypes-specific death (4.94 vs. 3.58 vs. 2.45 deaths/10(5) person-years), and an increase in non-PCV serotypes-specific death (2.55 vs. 3.70 vs. 4.09 deaths/10(5) person-years).

CONCLUSIONS

The use of PCVs for children was associated with a reduction of mortality from IPD in adults 18-64 years, through the indirect effect of herd protection. In older adults, age-related factors could play a role in IPD mortality.

Host Factors and Biomarkers Associated with Poor Outcomes in Adults with Invasive Pneumococcal Disease

BACKGROUND

Invasive pneumococcal disease (IPD) causes considerable morbidity and mortality. We aimed to identify host factors and biomarkers associated with poor outcomes in adult patients with IPD in Japan, which has a rapidly-aging population.

METHODS

In a large-scale surveillance study of 506 Japanese adults with IPD, we investigated the role of host factors, disease severity, biomarkers based on clinical laboratory data, treatment regimens, and bacterial factors on 28-day mortality.

RESULTS

Overall mortality was 24.1%, and the mortality rate increased from 10.0% in patients aged ˂50 years to 33.1% in patients aged ≥80 years. Disease severity also increased 28-day mortality, from 12.5% among patients with bacteraemia without sepsis to 35.0% in patients with severe sepsis and 56.9% with septic shock. The death rate within 48 hours after admission was high at 54.9%. Risk factors for mortality identified by multivariate analysis were as follows: white blood cell (WBC) count <4000 cells/μL (odds ratio [OR], 6.9; 95% confidence interval [CI], 3.7-12.8, p < .001); age ≥80 years (OR, 6.5; 95% CI, 2.0-21.6, p = .002); serum creatinine ≥2.0 mg/dL (OR, 4.5; 95% CI, 2.5-8.1, p < .001); underlying liver disease (OR, 3.5; 95% CI, 1.6-7.8, p = .002); mechanical ventilation (OR, 3.0; 95% CI, 1.7-5.6, p < .001); and lactate dehydrogenase ≥300 IU/L (OR, 2.4; 95% CI, 1.4-4.0, p = .001). Pneumococcal serotype and drug resistance were not associated with poor outcomes.

CONCLUSIONS

Host factors, disease severity, and biomarkers, especially WBC counts and serum creatinine, were more important determinants of mortality than bacterial factors.

Efficacy of PPV23 in Preventing Pneumococcal Pneumonia in Adults at Increased Risk--A Systematic Review and Meta-Analysis

Background

Pneumococcal community-acquired pneumonia (pCAP) is the most frequent form of pneumonia. The elderly and adults with underlying diseases are at an increased risk of developing pCAP. The 23-valent pneumococcal polysaccharide vaccine (PPV23) was licensed over 30 years ago and is recommended as the standard intervention in many countries across the globe, although its efficacy continues to be debated. We performed a meta-analysis of randomized controlled trials (RCTs) to investigate the effect of PPV23 for preventing pCAP in adults ≥60 years of age.

Methods

An existing Cochrane Review was updated to Oct 2014 using a systematic literature search to select appropriate RCTs. DerSimonian and Laird random-effects meta-analyses were performed and odd ratios (OR) with 95%-confidence intervals (CI) and p-values were calculated for the descriptive analyses. Reasons for heterogeneity were explored by subgroup analyses.

Results

Meta-analysis of PPV23 efficacy included four studies. Three of them did not demonstrate efficacy for PPV23. The body of evidence indicated statistically significant heterogeneity (I² = 78%, p = 0.004) that could be explained by subgroup analysis by “study setting”. Further effect modifiers for pCAP were “continent of trial” (p<0.01), and “method of pneumococcal diagnostics” (p = 0.001). Subgroup analyses revealed that the only study showing efficacy for PPV23 was an outlier. Overall, the validity of the meta-analytic PPV23 efficacy assessment was confirmed by the meta-analysis of all-cause CAP including six studies.

Discussion

Inconsistencies in PPV23 treatment effects to prevent pCAP could solely be explained by one outlier study that was performed in nursing homes in Japan. The effect modifier “method of pneumococcal diagnostics” should be interpreted carefully, since methodological weaknesses are not restricted to one special method only, which would justify the exclusion of certain studies. Overall, we conclude from our meta-analysis that to date there is no proof that PPV23 can prevent pCAP in a general, community-dwelling elderly population.

Risk and outcomes of invasive pneumococcal disease in adults with underlying conditions in the post-PCV7 era, The Netherlands

BACKGROUND

Immunocompromising conditions and advanced age (≥65 years) are associated with a high risk for invasive pneumococcal disease (IPD). We investigated the risk and outcomes of IPD in adults with underlying conditions in the post-PCV7 era in The Netherlands.

METHODS

IPD data from 2008 to 2012 was obtained from the national pneumococcal surveillance system, covering 25% of the Dutch population. Population estimates of underlying conditions were derived from the primary care data (2012). IPD incidence in adults with immunocompromising conditions (high risk group) and non-immunocompromising comorbidities (medium risk group) were compared to the "normal risk group" without diagnosed comorbidities. Case-fatality and ICU admission in the different risk groups was analyzed by logistic regression. Serotype specific propensities to affect high risk group IPD patients were calculated.

RESULTS

Adults with a high risk condition have a 18-fold (95% CI 15.6-21.2) and 3-fold (95% CI 2.6-3.9) higher risk compared to the normal risk group for IPD at age 18-64 years and 65 years and older, respectively. In case of a medium risk condition, the risk is 5-fold (95% CI 4.3-5.7) and 2-fold (95% CI 1.9-2.6) higher in age groups 18-64 and ≥65 years old. Likewise, IPD patients with a high or medium risk condition have a higher case-fatality (after adjustment for age, odds ratio: 2-fold (95% CI 1.5-3.5) and 1.4-fold (95% CI 1.0-2.1), respectively). Several serotypes (e.g. 6A, 6B, 23A and 23B) are associated with a significantly higher propensity to cause disease in high risk patients.

CONCLUSIONS

The risk for IPD and death in the post-PCV7 era has remained considerably high in adults and elderly with underlying conditions. The identification of serotypes with a high propensity to affect risk groups can be important for selecting (future) vaccine serotypes.

Incidence of invasive pneumococcal disease in 5-15 year old children with and without comorbidities in Germany after the introduction of PCV13: Implications for vaccinating children with comorbidities

OBJECTIVE

To describe the burden of suffering from IPD in children aged 5-15 years with and without comorbidities up to 5 years after the introduction of PCV13 in Germany and to identify the potential benefit for PCV13 and PPV23 vaccination.

METHODS

The surveillance of IPD for children <16 years was based on two independently reporting sources: active surveillance in pediatric hospitals and a laboratory-based sentinel surveillance system.

CASE DEFINITION

IPD with cultural detection of pneumococci at a physiologically sterile site in children from 2010 to 2014 in Germany. Incidence was estimated by capture-recapture analysis with stratification by absence/presence of comorbidities. Coverage of the observed serotypes by different vaccines was assessed.

RESULTS

142 (Capture recapture-corrected: 437) cases were reported: 72.5% were healthy children and 27.5% had a comorbidity. The incidence of IPD related to children with comorbidities was 0.2 per 100,000. One third of these cases had serotypes not included in either vaccine. The remaining cases might benefit from pneumococcal vaccination but one third of all cases was not vaccinated. The additional potential benefit of PPV23 compared to PCV13 with respect to coverage was 10%.

CONCLUSION

The incidence of IPD in children with comorbidities in Germany is low. Pneumococcal vaccination uptake in children with comorbidities should be increased, although only about two-thirds of the cases might be preventable by presently available vaccines.

Inflammatory Bowel Disease Patients Are at Increased Risk of Invasive Pneumococcal Disease: A Nationwide Danish Cohort Study 1977-2013

OBJECTIVES

Inflammatory bowel disease (IBD), Crohn's disease (CD), and ulcerative colitis (UC) are chronic diseases characterized by an inappropriate immune response, which may also increase the risk of infections. We investigated the risk of invasive pneumococcal disease (IPD) before and after diagnosis of IBD in a population-based cohort study.

METHODS

In a cohort of 74,156 IBD patients and 1,482,363 non-IBD controls included and followed during 1977-2013, hazard rate ratios (HRs) for IPD in IBD patients vs. controls were calculated by Cox regression. Within the IBD group, we also calculated the risk according to ever use of specific IBD medications. Next, using conditional logistic regression, we evaluated the odds of IPD prior to IBD diagnosis.

RESULTS

The HRs for IPD within the first 6 months after IBD diagnosis were significantly and more than threefold increased and then decreased to a constant level, which for CD was significantly increased (approximately twofold, HR, 1.99; 95% confidence interval (CI), 1.59-2.49) and for UC non-significantly just above 1. IBD medication use including tumor necrosis factor alpha antagonists had limited impact on the risk of IPD, although having ever used azathioprine increased the risk of IPD in patients with UC (HR, 2.38; 95% CI, 1.00-5.67). Up to 4 years prior to IBD diagnosis, the odds ratio for IPD was significantly increased (UC HR, 1.51, 95% CI, 1.05-2.17; CD HR, 1.79, 95% CI, 1.05-3.03).

CONCLUSIONS

The risk of IPD is significantly increased both before and after diagnosis of IBD, with limited impact of IBD medications. This suggests that the risk of IPD in patients with IBD is related to the underlying altered immune response in these patients.

Rates of pneumonia among children and adults with chronic medical conditions in Germany

Background

The objective of this study is to evaluate rates of all-cause pneumonia among “at-risk” and “high-risk” children and adults in Germany—in comparison with age-stratified healthy counterparts—during the period following the 2006 recommendation for universal immunization of infants with pneumococcal conjugate vaccine.

Methods

Retrospective cohort design and healthcare claims information for 3.4 M persons in Germany (2009–2012) were employed. Study population was stratified by age and risk profile (healthy, “at-risk” [with chronic medical conditions], and “high-risk” [immunocompromised]). At-risk and high-risk conditions, as well as episodes of all-cause pneumonia, were identified via diagnosis, procedure, and drug codes.

Results and discussion

Rates of all-cause pneumonia were 1.7 (95 % CI 1.7-1.8) to 2.5 (2.4-2.5) times higher among children and adults with at-risk conditions versus healthy counterparts, and 1.8 (1.8-1.9) to 4.1 (4.0-4.2) times higher among children and adults with high-risk conditions. Rates of all-cause pneumonia among at-risk persons increased in a graded and monotonic fashion with increasing numbers of conditions (i.e., risk stacking).

Conclusions

An increased risk for all-cause pneumonia in German children and adults with a spectrum of medical conditions persists in the era of widespread pneumococcal vaccination, and pneumonia risk in persons with ≥2 at-risk conditions is comparable or higher than those with high-risk conditions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1162-y) contains supplementary material, which is available to authorized users.

Pneumococcal Carriage and Vaccine Coverage in Retirement Community Residents

OBJECTIVES

To evaluate pneumococcal immunization in older adults living in retirement communities and to measure nasopharyngeal carriage of Streptococcus pneumoniae to better assess the potential for herd protection from the 13-valent pneumococcal conjugate vaccine (PCV-13) in these settings.

DESIGN

Cross-sectional observational study of adults aged 65 and older living in retirement communities to determine coverage with 23-valent pneumococcal vaccine (PPSV-23), coverage with PCV-13 in immuncompromised individuals according to 2012 Advisory Committee on Immunization Practices (ACIP) guidelines, and nasopharyngeal carriage of S. pneumoniae.

SETTING

Two retirement communities in North Carolina.

PARTICIPANTS

Older adults recruited between December 2013 and April 2014 (N = 21, 64.8% female, mean age 81.4).

MEASUREMENTS

A survey was used to assess chronic illnesses, immunization history, and potential risk factors for pneumococcal carriage; a chart review was used to confirm immunization history and abstract chronic conditions; and a nasopharyngeal swab was collected and cultured for S. pneumoniae.

RESULTS

Eighty-seven percent of participants reported receiving PPSV-23 since age 65. Of the 16.2% of participants with an immunocompromising condition, only one had received PCV-13. Nasopharyngeal carriage with S. pneumoniae was detected in 1.9% (95% confidence interval = 0.0-3.8%) of participants.

CONCLUSION

In this select sample, PPSV-23 coverage was high, but adherence to the ACIP recommendation for PCV-13 in immunocompromised groups was low. Nasopharyngeal carriage of S. pneumoniae was present, although infrequent, suggesting that immunization with PCV-13 could provide an individual benefit and a small degree of herd protection.

A comparative public health and budget impact analysis of pneumococcal vaccines: The French case

In 2002, a pneumococcal conjugate vaccine (PCV) was introduced to French infants and toddlers. A change has been witnessed in the incidence of pneumococcal diseases in adults: the incidence of invasive pneumococcal disease (IPD) of serotypes covered by PCV decreased, and serotypes not covered by PCV increased. This study aimed to quantify the public health and budget impact of pneumococcal vaccination strategies in at-risk adults in France over 5 years. A previously published population-based Markov model was adapted to the French situation. At-risk adults received either PPV23 (pneumococcal polysaccharide vaccine; for the immunocompetent) or PCV13 (for the immunosuppressed). The strategy was compared to PCV13 alone. Uncertainty was addressed using extreme scenario analyses. Between 2014 and 2018, vaccination with PPV23/PCV13 led to a higher reduction in terms of IPD and non-bacteremic pneumococcal pneumonia cases avoided in most scenarios analyzed when compared to PCV13 alone. For budget impact, none of the scenarios was in favor of PCV13. Under conservative coverage assumptions, the total incremental budget impact ranged from € 39.8 million to € 69.3 million if PCV13 were to replace PPV23 in the immunocompetent. With the epidemiological changes of pneumococcal diseases and the broader serotype coverage of PPV23, the current program remains an optimal strategy from public health perspective. Given the additional budget required for the use of PCV13 alone and its uncertain public health benefits, vaccination with PPV23 remains the preferred strategy.

Which individuals are at increased risk of pneumococcal disease and why? Impact of COPD, asthma, smoking, diabetes, and/or chronic heart disease on community-acquired pneumonia and invasive pneumococcal disease

Pneumococcal disease (including community-acquired pneumonia and invasive pneumococcal disease) poses a burden to the community all year round, especially in those with chronic underlying conditions. Individuals with COPD, asthma or who smoke, and those with chronic heart disease or diabetes mellitus have been shown to be at increased risk of pneumococcal disease compared with those without these risk factors. These conditions, and smoking, can also adversely affect patient outcomes, including short-term and long-term mortality rates, following pneumonia. Community-acquired pneumonia, and in particular pneumococcal pneumonia, is associated with a significant economic burden, especially in those who are hospitalised, and also has an impact on a patient's quality of life. Therefore, physicians should target individuals with COPD, asthma, heart disease or diabetes mellitus, and those who smoke, for pneumococcal vaccination at the earliest opportunity at any time of the year.

Cost-effectiveness of adult pneumococcal conjugate vaccination in the Netherlands

The Community-Acquired Pneumonia Immunization Trial in Adults (CAPiTA) demonstrated the efficacy of 13-valent pneumococcal conjugate vaccine (PCV13) in preventing vaccine-type community-acquired pneumonia and vaccine-type invasive pneumococcal disease in elderly subjects. We examined the cost-effectiveness of PCV13 vaccination in the Netherlands.

Using a Markov-type model, incremental cost-effectiveness ratios (ICER) of PCV13 vaccination in different age- and risk-groups for pneumococcal disease were evaluated using a societal perspective. Estimates of quality-adjusted life-years (QALYs), costs, vaccine efficacy and epidemiological data were based on the CAPiTA study and other prospective studies. The base-case was PCV13 vaccination of adults aged 65–74 years compared to no vaccination, assuming no net indirect effects in base-case due to paediatric 10-valent pneumococcal conjugate vaccine use. Analyses for age- and risk-group specific vaccination strategies and for different levels of hypothetical herd effects from a paediatric PCV programme were also conducted.

The ICER for base-case was €8650 per QALY (95% CI 5750–17 100). Vaccination of high-risk individuals aged 65–74 years was cost-saving and extension to medium-risk individuals aged 65–74 years yielded an ICER of €2900. Further extension to include medium- and high-risk individuals aged ≥18 years yielded an ICER of €3100.

PCV13 vaccination is highly cost-effective in the Netherlands. The transferability of our results to other countries depends upon vaccination strategies already implemented in those countries.

Vaccinating the elderly with 13-valent pneumococcal conjugate vaccine is highly cost-effectivehttp://ow.ly/NVeui

Epidemiological burden of invasive pneumococcal disease in children and adolescents with predisposing risk factors

OBJECTIVE

Some medical conditions constitute important risk factors for the development of invasive pneumococcal diseases in children and adolescents aged from 5 to 19 years. Conjugate vaccines have potential efficacy in this scenario, but are not available in many Latin American public healthcare systems for this age group. This study aimed to estimate the preventable fraction of invasive pneumococcal diseases among individuals aged from 5 to 19 years with associated risk factors for its development.

METHODS

Data regarding the Latin America population, risk factors prevalence and conjugate vaccines efficacy were obtained from the literature.

RESULTS

Total population at risk ranged from 17.3 to 64.6 million of individuals and asthma was the most impacting risk factor. According to SIREVA, PCV13 provided a 62.9% serotypes coverage in individuals from 5 to 29 years in 2012, potentially increasing the covered population from [8,338,457-31,057,620] with PCV10 to [10,906,356-40,622,078] with PCV13. To date, according to available efficacy data, the hypothetically immunized population ranged from 11.4 to 42.4 million, representing 7.0% to 26.0% of the total population in this age group.

CONCLUSIONS

Vaccination in risk groups should be encouraged, as it potentially contributes to the reduction in the number of cases of invasive pneumococcal disease.

Incidence, direct costs and duration of hospitalization of patients hospitalized with community acquired pneumonia: A nationwide retrospective claims database analysis

BACKGROUND

Community-acquired pneumonia (CAP) is one of the most common acute infections associated with a substantial clinical and economic burden. There have been few studies assessing incidence rate, duration of hospitalization, and costs of hospitalized CAP by age and care-setting.

METHODS

A retrospective study was conducted using a nationwide Dutch database containing healthcare claims data of 16.7 million inhabitants. Patients with at least one claim with a discharge diagnosis of CAP between January 2008 and December 2011 were selected. The main outcome measures considered were the incidence rate, duration of hospitalization, and the direct costs of hospitalized CAP stratified by age and care-setting.

RESULTS

In total, 195,372 CAP cases were included in the analysis resulting in an average incidence of 295 per 100,000 population per year. Sixty-three percent (123,357) of the included patients were hospitalized for 1 or more nights, of which 5.9% (n=7241) spent at least one night in the Intensive Care Unit (ICU). Overall, these 123,357 patients spent 824,985 days in the hospital of which 48,324 were spent on the ICU. The mean duration of hospitalization of ICU patients and general ward patients was 15.2 days and 6.2 days, respectively. The total costs related to all 195,372 CAP episodes during these 4 years were €711 million, with the majority (76%) occurring among those aged 50 years and older. Median (and mean) costs were dependent on age and type of care with costs ranging from €344 (€482) per episode for 0-9 year olds treated in the outpatient hospital setting up to €10,284 (€16,374) per episode for 50-64 year olds admitted to the ICU.

CONCLUSION

There is a large variation in terms of incidence, disease burden and costs across different age groups and the treatment setting. Effective interventions, targeted at older adults, to prevent pneumonia could reduce the (financial) burden due to pneumonia.

[Prevention of Streptococcus pneumoniae (pneumococcal) infections in adults]

Infections caused by Streptococcus pneumoniae (pneumococcus) are still meaning a serious health problem, about 40% of community acquired pneumonia (CAP) is due to pneumococcal bacteria in adults requiring hospitalization. The incidence and mortality rate of pneumococcal infections is increasing in the population above 50 years of age. Certain congenital and acquired immunocompromised conditions make the individual susceptible for pneumococcal infection and other chronic comorbidities should be considered as a risk factor as well, such as liver and renal diseases, COPD, diabetes mellitus. Lethality of severe pneumococcal infections with bacteraemia still remains about 12% despite adequate antimicrobial therapy in the past 60 years. Underestimation of pneumococcal infections is mainly due to the low sensitivity of diagnostic tools and underuse of bacteriological laboratory confirmation methods. 13-valent pneumococcal conjugate vaccine (PCV-13) became available recently beyond the 23-valent polysacharide vaccine (PPV-23) which has been using for a long time.The indication and proper administration of the two vaccines are based on international recommendations and vaccination guideline published by National Centre for Epidemiology (NCE):Pneumococcal vaccination is recommended for: Every person above 50 years of age. Patients of all ages with chronic diseases who are susceptible for severe pneumococcal infections: respiratory (COPD), heart, renal, liver disease, diabetes, or patients under immunsuppressive treatment. Smokers regardless of age and comorbidities. Cochlear implants, cranial-injured patients. Patients with asplenia.Recommendation for administration of the two different vaccines:Adults who have not been immunized previously against pneumococcal disease must be vaccinated with a dose of 13-valent pneumococcal conjugate vaccine first. This protection could be extended with administration of 23-valent pneumococcal polysaccharide vaccine at least two month later. Adults who have been immunized previously, but above 65 years of age, with a 23-valent polysaccharide vaccine are recommended to get one dose of conjugate vaccine at least one year later. Adults who have been immunized previously, but under 65 years of age, with a 23-valent polysaccharide vaccine are recommended to get one dose of conjugate vaccine at least one year later. After a minimal interval of two months one dose of 23-valent pneumococcal polysaccharide vaccine is recommended if at least 5 years have elapsed since their previous PPSV23 dose. Vaccination of immuncompromised patients (malignancy, transplantation, etc.) and patients with asplenia should be defined by vaccinology specialists. Pneumococcal vaccines may be administered concommitantly or any interval with other vaccines.

[Streptococcus pneumoniae: serotype distribution, antimicrobial susceptibility, risk factors and mortality in Galicia over a two year-period]

INTRODUCTION

To examine the epidemiology of pneumococcal infection in Galicia (Spain) after the incorporation of the pneumococcal conjugate vaccine, and to determine serotype distribution, antibiotic susceptibility, risk factors and associated mortality in cases of invasive pneumococcal disease (IPD) during 2011 and 2012.

METHODS

All strains causing IPD in Galicia were studied. Serotyping was performed by agglutination and Quellung reaction. Antibiotic sensitivity to penicillin, cefotaxime, erythromycin, vancomycin, and levofloxacin was determined. The risk factors considered were chronic respiratory disease, heart disease, liver disease, kidney disease, diabetes mellitus, and HIV and non-HIV immunodeficiency.

RESULTS

A total of 555 strains were collected, with 43 different serotypes being found. The most frequently isolated ones were: serotype3 (17.5%), serotype7F (12.6%), serotype19A (9.4%), serotype14 (4.1%), serotype6C (4.1%), serotype11A (4%) and serotype22F (3.8%). 57.1% of isolates were serotypes included in VNC-13V. Two non-penicillin-sensitive strains and two others were not sensitive to cefotaxime, and 24.7% of the strains were not susceptible to erythromycin (26.9% in 2011 and 22.5% in 2012). The case fatality rate was 16.5%, reaching 23.3% in patients over 75years. Diseases with a statistically significant risk of mortality were: liver, kidney and immunodeficiency without HIV.

CONCLUSIONS

Serotype3 was the most frequent in Galicia. Very few strains were not susceptible to penicillin. Erythromycin resistance decreased from 2011 to 2012. It is highlighted that mortality increases with age. Liver disease, renal disease and non-HIV immunodeficiency increases the mortality risk.

Increased risk for and mortality from invasive pneumococcal disease in HIV-exposed but uninfected infants aged <1 year in South Africa, 2009-2013

BACKGROUND

High antenatal human immunodeficiency virus (HIV) seroprevalence rates (∼ 30%) with low perinatal HIV transmission rates (2.5%), due to HIV prevention of mother-to-child transmission program improvements in South Africa, has resulted in increasing numbers of HIV-exposed but uninfected (HEU) children. We aimed to describe the epidemiology of invasive pneumococcal disease (IPD) in HEU infants.

METHODS

We conducted a cross-sectional study of infants aged <1 year with IPD enrolled in a national, laboratory-based surveillance program for incidence estimations. Incidence was reported for 2 time points, 2009 and 2013. At enhanced sites we collected additional data including HIV status and in-hospital outcome.

RESULTS

We identified 2099 IPD cases in infants from 2009 to 2013 from all sites. In infants from enhanced sites (n = 1015), 92% had known HIV exposure status and 86% had known outcomes. IPD incidence was highest in HIV-infected infants, ranging from 272 to 654 per 100,000 population between time points (2013 and 2009), followed by HEU (33-88 per 100,000) and HIV-unexposed and uninfected (HUU) infants (18-28 per 100,000). The case-fatality rate in HEU infants (29% [74/253]) was intermediate between HUU (25% [94/377]) and HIV-infected infants (34% [81/242]). When restricted to infants <6 months of age, HEU infants (37% [59/175]) were at significantly higher risk of dying than HUU infants (32% [51/228]; adjusted relative risk ratio, 1.76 [95% confidence interval, 1.09-2.85]).

DISCUSSION

HEU infants are at increased risk of IPD and mortality from IPD compared with HUU children, especially as young infants. HEU infants, whose numbers will likely continue to increase, should be prioritized for interventions such as pneumococcal vaccination along with HIV-infected infants and children.

The association between asthma and invasive pneumococcal disease: a nationwide study in Korea

The purpose of this study was to investigate the association between asthma and invasive pneumococcal disease (IPD) in Korea. A retrospective population-based cohort study was conducted using the Korean Health Insurance Review and Assessment database 2010-2011. The subjects included 935,106 (2010) and 952,295 (2011), of whom 398 (2010) and 428 (2011) patients with IPD were identified. There was significant difference in the prevalence of IPD in patients with and without asthma (0.07% vs. 0.02% in 2010 and 0.08% vs. 0.01% in 2011; P<0.001). After adjusting for age and gender, patients with asthma showed over a three-fold increased risk of IPD compared with patients without asthma (adjusted odds ratio [aOR] 3.90, 95% confidence interval [CI] 3.02-5.03 in 2010 / aOR, 5.44; 95% CI, 4.10-7.22 in 2011; P<0.001). These findings were also significant in children (aOR, 2.08; 95% CI, 1.25-3.45 in 2010; P=0.005 / aOR, 3.26; 95% CI, 1.74-6.11 in 2011; P<0.001). Although diabetes mellitus was also significantly associated with IPD, relatively low ORs compared with those of asthma were noted (aOR, 1.85; 95% CI, 1.35-2.54 in 2010 / aOR, 2.40; 95% CI, 1.78-3.24 in 2011; P<0.001). Both children and adults with asthma are at increased risk of developing IPD.

Pneumococcal vaccination: what have we learnt so far and what can we expect in the future?

Individuals <2 years and ≥ 50 years of age, as well as those with other specific risk factors, are especially vulnerable to invasive pneumococcal disease (IPD). Conjugate vaccines have been developed against encapsulated bacteria such as Streptococcus pneumoniae to provide improved immune responses. The 7-valent pneumococcal conjugate vaccine (PCV7) has significantly reduced the burden of vaccine-type pneumococcal diseases in children, including invasive disease and pneumonia and acute otitis media. There have also been significant declines in antimicrobial resistance in 7-valent vaccine serotypes and carriage of S. pneumoniae in the post-PCV7 era. Two to three years after the introduction of PCV13, there is emerging, global evidence of a reduced burden of pneumococcal diseases in children, including declines in IPD (UK and Germany) and nasopharyngeal carriage of PCV13 serotypes (Portugal and France). The functional immunogenicity of PCV13 in individuals ≥ 50 years of age has been demonstrated in clinical trials in comparison with the 23-valent pneumococcal polysaccharide vaccine and for children and adults 6 to 49 years of age. Between 2011 and 2013, PCV13 received market authorisation by the European Medicines Agency (EMA) for these additional age groups and is now available in Europe for the prevention of pneumococcal disease in all age groups.

Glycoconjugate vaccines: an update

INTRODUCTION

Globally, the three main pathogens causing serious infections are Haemophilus influenzae type b, Streptococcus pneumoniae and Neisseria meningitidis. Over the last 5 years, new vaccines protecting against these bacteria have been developed and introduced in various countries.

AREAS COVERED

This review describes the recently licensed glycoconjugates being used to protect against these encapsulated bacteria. Immunogenicity and safety data that led to licensure or licensure expansion of these glycoconjugates are discussed in addition to the resultant impact on the disease burden.

EXPERT OPINION

The maintenance of robust immunisation programmes with high uptake rates is important in maintaining low rates of disease. Epidemiological surveillance systems are essential in monitoring any changes in infectious disease trends and in identifying emerging infections such as from non-typeable H. influenzae, pneumococcal serotype replacement disease and changes in the epidemiology of meningococcal serogroups. This is important to guide future vaccine development. Accessibility of these glycoconjugate vaccines in resource poor regions, which bear the highest disease burden from these pathogens, remains challenging largely due to high vaccine pricing. Recent aids from public and private funding, tiered vaccine pricing and the transfer of vaccine technology have helped in introducing these vaccines where they are most needed.

[Reasons for adult immunization -- prevention of most frequent respiratory infections]

The adult vaccination is utilized insufficiently as a preventive method currently, even the incidence and mortality of vaccine-preventable infections is very high in the elderly and patients with immunocompromised conditions. They should be protected due to many reasons: the rate of these individuals are getting higher in the population, the effectiveness of antibiotic therapy is limited and becoming more significant due to antibiotic resistance, the quality of life in survivors of severe infections is deteriorated, resulting huge burden to the individual and society as well. The impaired functions of immune system with the advancing age cause higher morbidity and mortality especially in respiratory infections, it is representing in the incidence and high lethality of community acquired pneumonia in older adults. Beyond the old polysaccharide vaccine (PPV23) the inclusion of new conjugate vaccine (PCV13) means a significant improvement in the prevention of pneumococcal infections, providing a possibility to prevent not just pneumococcal infections with bacteraemia caused by serotypes presented in the vaccine, but non-bacteraemic pneumonias as well. The necessity of flu vaccines cannot be stressed enough even the vaccines is not so effective in elderly than in younger adults: annual immunization against influenza administering together with pneumococcal vaccination decrease significantly the number, severity and complications in older adults as well. Further improvement in protection of immunocompromised patients is the establishment of cocoon immunity with the vaccination of close contacts.

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

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

Adult vaccination

Vaccination of children has had a major impact on the morbidity and mortality of many infectious diseases globally. However, with age, immune responses to vaccines can be less robust, which can be further enhanced by underlying diseases that are common in the older adult. In many countries around the globe booster vaccinations against diphtheria, tetanus, and pertussis are recommended for adults. For the older adult, vaccination against pneumococcal diseases, influenza and herpes zoster are also recommended. Despite these recommendations, the widespread use of these vaccines in the adult population clearly lags behind the vaccine uptake and successes documented for pediatric vaccination programs. Furthermore, extensive and sometimes inappropriate use of antibiotics have fostered the emergence of antibiotic-resistant bacteria (e.g., methicillin resistant Staphylococcus aureus (MRSA)) as well as increased susceptibility in the elderly to bacterial species such as Clostridium difficile. Infectious diseases remain an important unmet medical need and new concepts to successfully implement vaccination of adults are urgently needed.

Cost-effectiveness of vaccinating the elderly and at-risk adults with the 23-valent pneumococcal polysaccharide vaccine or 13-valent pneumococcal conjugate vaccine in the UK

OBJECTIVE

The introduction of routine childhood vaccination with pneumococcal conjugate vaccines (PCVs) has led to a decrease in the overall incidence of pneumococcal disease in all ages and a change in the serotype distribution of the remaining disease. This study assessed the cost-effectiveness of vaccinating ≥65 years and at risk adults with either the 23-valent pneumococcal polysaccharide vaccine (PPV23) or the 13-valent conjugate vaccine (PCV13) in the UK, accounting for epidemiological changes.

METHODS

A population-based Markov model was used to track one UK-based cohort of individuals assuming PPV23, PCV13 or no vaccination until death.

RESULTS

The ICER was estimated at £8413 when PPV23 was compared to no vaccination. PPV23 dominated PCV13.

CONCLUSION

This model suggests that vaccinating with PPV23 is cost-effective when compared to both PCV13 and no vaccination. As PPV23 covers 80-90% in the UK of all serotypes causing invasive pneumococcal diseases, it remains cost-effective despite recent reductions in invasive pneumococcal diseases incidence in adults.