Risk Of Pneumococcal Pneumonia Research Articles

Clinical Features and Outcomes of Community-Acquired Pneumonia Caused by Haemophilus Influenza.

BackgroundLong regarded as the second most common cause of community-acquired pneumonia (CAP), Haemophilus influenzae has recently been identified with almost equal frequency as pneumococcus in patients hospitalized for CAP. The literature lacks a detailed description of the presentation, clinical features, laboratory and radiologic findings, and outcomes in Haemophilus pneumonia.MethodsDuring 2 prospective studies of patients hospitalized for CAP, we identified 33 patients with Haemophilus pneumonia. In order to provide context, we compared clinical findings in these patients with findings in 36 patients with pneumococcal pneumonia identified during the same period. We included and analyzed separately data from patients with viral coinfection. Patients with coinfection by other bacteria were excluded.ResultsHaemophilus pneumonia occurred in older adults who had underlying chronic lung disease, cardiac conditions, and alcohol use disorder, the same population at risk for pneumococcal pneumonia. However, in contrast to pneumococcal pneumonia, patients with Haemophilus pneumonia had less severe infection as shown by absence of septic shock on admission, less confusion, fewer cases of leukopenia or extreme leukocytosis, and no deaths at 30 days. Viral coinfection greatly increased the severity of Haemophilus, but not pneumococcal pneumonia.ConclusionsWe present the first thorough description of Haemophilus pneumonia, show that it is less severe than pneumococcal pneumonia, and document that viral coinfection greatly increases its severity. These distinctions are lost when the label CAP is liberally applied to all patients who come to the hospital from the community for pneumonia.

Incidence and Risk of Pneumococcal Pneumonia in Adults with Distinct Underlying Medical Conditions: A Population-Based Study.

This study investigated the incidence of pneumococcal pneumonia requiring hospitalisation among middle-aged and older adults with and without specific underlying medical conditions, evaluating the influence of these conditions in the risk of developing pneumonia. Population-based prospective cohort study included 2,025,730 individuals ≥ 50years around Catalonia, Spain. The Catalonian information system for the development of research in primary care (SIDIAP) was used to establish baseline characteristics of the cohort (comorbidities and underlying medical conditions). Hospitalisations from pneumococcal pneumonia occurred among cohort members between 01/01/2015 and 31/12/2015 were collected from hospital discharge codes of 68 reference Catalonian hospitals. Cox regression was used to estimate the association between baseline conditions and the risk of developing pneumonia. Global incidence rate (IR) of hospitalised pneumococcal pneumonia was 82.8 cases per 100,000 persons-year. Maximum IRs (per 100,000 persons-year) emerged among persons with haematological neoplasia (837.4), immunodeficiency (709.2), HIV infection (474.7), severe renal disease (407.5) and chronic pulmonary disease (305.7). In the multivariable analyses, apart from increasing age, HIV infection (hazard ratio [HR] 6.78), haematological neoplasia (HR 6.30), prior all-cause pneumonia (HR 5.27), immunodeficiency (HR 4.57) and chronic pulmonary disease (HR 2.89) were the conditions most strongly associated with an increasing risk. Pneumococcal vaccination did not emerge associated with a reduced risk in our study population (nor PPsV23 neither PCV13). Old age, immunocompromising conditions and chronic pulmonary/respiratory disease are major risk factors for pneumococcal pneumonia in adults. Our data underline the need for better prevention strategies in these persons.

Lower socioeconomic status predicts lower pneumococcal antibody titers among young adults with asthma

Despite the significantly increased risk of invasive pneumococcal disease among patients with asthma, the association of socio-economic status (SES) with antibody titers is not known. We conducted a prospective study to assess the association of pneumococcal titers and immune response to PPSV23 to SES. We prospectively enrolled 50 asthmatics between 19-21 years old that did not have a history of PPSV23 from Mayo Clinic primary care practice. One person in 50 had PCV-7 while none had PCV-13 immunization in childhood. Pneumococcal titers for 23 serotypes were measured at baseline and 6 weeks post vaccination. SES was measured by HOUSES, a validated individual-level housing-based SES index (the higher HOUSES, the greater SES). The study approval and oversight was by the Mayo Clinic IRB. Asthma control test (ACT) scores at baseline did not differ by SES measured by HOUSES among subjects. A majority of baseline titers of PPSV23 showed positive association with HOUSES (P<0.05 for 7 titers: 1, 10A, 12F, 15B, 18C, 19F, 22F, 5, 7F, 8 and p: 0.05-0.1 for 4 titers: 23F, 3, 9N and 9V). Fold change of 20 out of 23 titers showed no association with HOUSES. Lower SES is associated with lower baseline PPSV23 titers and SES may be an unrecognized determinant of vaccine responses. PPSV23 vaccination may reduce health disparities by SES in risk of pneumococcal pneumonia in asthmatics. While the mechanisms underlying this observation are studied, whether this observation is true for other vaccine titers need to be elucidated.

Decreased relative risk of pneumococcal pneumonia during the last decade, a nested case-control study

BackgroundStreptococcus pneumoniae (SP) is one of the most common pathogens of Community-Acquired Pneumonia (CAP), but recent reports suggest that its incidence may be declining in relation to the use of the conjugate 13-valent pneumococcal vaccine in children. We compared the result of the immunochromatographic SP urinary antigen test (SPUAT) and clinical outcomes in patients with CAP admitted in two periods of time: 2001–2002(CAP1) and 2015–2016(CAP2).MethodsThis was a matched nested case-control study of two prospectively recorded cohorts of patients admitted with CAP, with SPUAT and blood culture performed in all patients. CAP2 cases and CAP1 controls were matched for age ± 4 years, sex, and Pneumonia Severity Index (PSI) score ± 10 points. Odds ratios (OR) for having SPUAT positive was estimated by conditional logistic regression. A multivariate model assessed the contribution of individual variables.ResultsFour hundred ninety-eight patients were recruited; 307 during the CAP1 and 191 during the CAP2 periods. Comparing both periods we observed differences, in age, PSI score, and the percentage of smokers, outpatients, previously immunized with pneumococcal vaccine, and positive SPUAT. On the other hand, mortality, admission from nursing homes, pneumococcal bacteremia and hospital admission were not different. After matching, pneumonia due to SP per the SPUAT was observed in 34(23.4%) of CAP1 and in 12(8.3%) of CAP2 patients (p < 0.001), and 6/145 CAP1 vs 33/145 CAP2 patients had received pneumococcal immunization before their admission (p < 0.001). A multivariate analysis confirmed that, independent of falling into PSI class 5, having not received the pneumococcal vaccine and having not survived the episode of pneumonia, there were two factors that increased the probability of having SPUAT positive: developing pneumonia during the CAP1 period (OR = 1.23) and having pneumococcal bacteremia (OR = 2.66).ConclusionWe observed a reduction of the role of SP as pathogen, along with an increase in the number of patients who received pneumococcal immunization before admission, in 2015-2016 compared to 2001-2002. In addition, the use of conjugate 13-valent vaccine, starting in 2012 for childhood immunization, could be an additional factor contributing to these changes, as a result of early herd immunity in adults pneumonia.

Anti-protein immunoglobulin M responses to pneumococcus are not associated with aging

BackgroundThe incidence of community-acquired pneumonia and lower respiratory tract infection rises considerably in later life. Immunoglobulin M (IgM) antibody levels to pneumococcal capsular polysaccharide are known to decrease with age; however, whether levels of IgM antibody to pneumococcal proteins are subject to the same decline has not yet been investigated.MethodsThis study measured serum levels and binding capacity of IgM antibody specific to the pneumococcal surface protein A (PspA) and an unencapsulated pneumococcal strain in serum isolated from hospital patients aged < 60 and ≥ 60, with and without lower respiratory tract infection. A group of young healthy volunteers was used as a comparator to represent adults at very low risk of pneumococcal pneumonia. IgM serum antibody levels were measured by enzyme-linked immunosorbent assay (ELISA) and flow cytometry was performed to assess IgM binding capacity. Linear regression and one-way analysis of variance (ANOVA) tests were used to analyse the results.ResultsLevels and binding capacity of IgM antibody to PspA and the unencapsulated pneumococcal strain were unchanged with age.ConclusionsThese findings suggest that protein-based pneumococcal vaccines may provide protective immunity in the elderly.Trial registrationThe LRTI trial (LRTI and control groups) was approved by the National Health Service Research Ethics Committee in October 2013 (12/NW/0713). Recruitment opened in January 2013 and was completed in July 2013. Healthy volunteer samples were taken from the EHPC dose-ranging and reproducibility trial, approved by the same Research Ethics Committee in October 2011 (11/NW/0592). Recruitment for this study ran from October 2011 until December 2012. LRTI trial: (NCT01861184), EHPC dose-ranging and reproducibility trial: (ISRCTN85403723).

Evaluating clinical effectiveness of 13-valent pneumococcal conjugate vaccination against pneumonia among middle-aged and older adults in Catalonia: results from the EPIVAC cohort study

BackgroundBenefits using the 13-valent pneumococcal conjugate vaccine (PCV13) in adults are controversial. This study investigated clinical effectiveness of PCV13 vaccination in preventing hospitalisation from pneumonia among middle-aged and older adults.MethodsPopulation-based cohort study involving 2,025,730 individuals ≥50 years in Catalonia, Spain, who were prospectively followed from 01/01/2015 to 31/12/2015. Primary outcomes were hospitalisation for pneumococcal or all-cause pneumonia and death from any cause. Cox regression models were used to evaluate the association between PCV13 vaccination and the risk of each outcome, adjusting for age, sex and major comorbidities/underlying risk conditions.ResultsCohort members were observed for a total of 1,990,701 person-years, of which 6912 person-years were PCV13 vaccinated. Overall, crude incidence rates (per 100,000 person-years) were 82.8 (95% confidence interval [CI]: 77.7–88.1) for pneumococcal pneumonia, 637.9 (95% CI: 599.0–678.7) for all-cause pneumonia and 2367.2 (95% CI: 2222.8–2518.7) for all-cause death. After multivariable adjustments we found that the PCV13 vaccination did not alter significantly the risk of pneumococcal pneumonia (multivariable-adjusted hazard ratio [mHR]: 1.17; 95% CI: 0.75–1.83; p = 0.493) and all-cause death (mHR: 1.07; 95% CI: 0.97–1.18; p = 0.190), although it remained significantly associated with an increased risk of all-cause pneumonia (mHR: 1.69; 95% CI: 1.48–1.94; p < 0.001). In stratified analyses focused on middle-aged or elderly persons and immunocompromised or immunocompetent subjects, PCV13 vaccination did not appear effective either.ConclusionOur data does not support clinical benefits of PCV13 vaccination against pneumonia among adults in Catalonia. It must be closely monitored in future studies involving more vaccinated person-time at-observation.

Pneumococcal vaccines: understanding centers for disease control and prevention recommendations.

Streptococcus pneumoniae infection is a common and serious health problem that is best prevented by the pneumococcal vaccine. The first vaccine approved by the U.S. Federal Drug Administration in 1977 contained 14 polysaccharide antigens. An improved vaccine introduced in 1983 included 23 polysaccharide antigens. Both vaccines were effective for immunocompetent adults; however, young children and immunocompromised adults remained susceptible. A pediatric vaccine was developed consisting of the capsular antigens of seven pneumococcal serotypes commonly found in children. The antigens in this preparation are covalently conjugated to diphtheria protein to make them more antigenic. The conjugate vaccine was expanded to include 13 serotypes by 2010. Although more immunogenic, the conjugate vaccine has fewer serotypes than the older 23-valent vaccine. The U.S. Centers for Disease Control and Prevention recommend that children at risk for pneumococcal pneumonia as defined by the presence of chronic disease should receive the 13-valent conjugated vaccine. Adults at risk for pneumococcal pneumonia, which includes those over 65 years of age and those who have a chronic disease, should receive the 23-polysaccharide vaccine. Immunosuppressed patients of any age should receive both vaccines. Adults should be revaccinated once at age 65 years or older with the 23-polysaccharide vaccine provided that at least 5 years have elapsed since the previous vaccination.

Is there an authentic increased risk of pneumococcal pneumonia among young mothers whose children were fully vaccinated with PCV7? The role of methodological shortcomings

We read with interest the manuscript of Hak et al ., who car-ried out a nested case-control study in the U.K. to assess the riskof pneumococcal pneumonia in young mothers, whose children were vaccinated with 3 doses of 7-valent pneumococcal-conjugate-vaccine (PCV7) by 24 months of age. The Authors hypothesizedthat the increased risk of pneumonia is a consequence of a serotypereplacement following pneumococcal vaccination. However, publichealth advantages related to prevention of pneumococcal diseasedue to vaccination were not adequately pointed out; consequently,the low impact of the maternal risk ( i . e ., only 6 cases/45,000 person-year in the group aged 20–24 years were registered) deserves tobe more emphasized, rather than focusing only on the strengthof the association. Furthermore, the incidence rate detected inthe age-group 20–24 years largely contributed to the changeof the overall incidence (from 61 to 81 cases per 100,000 in 2006 and 2010, respectively), but it was not possible to understand if the temporal trend of the incidence rates was statistically significant.

Clinical effectiveness of 23-valent pneumococcal polysaccharide vaccine against pneumonia in patients with chronic pulmonary diseases

Background The effectiveness of the 23-valent polysaccharide pneumococcal vaccine (PPV-23) is controversial, especially among people with high-risk conditions. This study assessed the clinical effectiveness of vaccination against pneumonia among patients with chronic pulmonary diseases.Methods We conducted a population-based case-control study including 96 non-immunocompromised patients with clinical diagnosis of chronic pulmonary disease (chronic bronchitis, emphysema and/or asthma), aged 50 y or older, with radiographically confirmed pneumococcal pneumonia (19 bacteremic and 77 nonbacteremic cases) and 192 outpatient control subjects with similar chronic pulmonary diseases (matched by primary care center, age, sex and main comorbidity). Adjusted odds ratios (ORs) for vaccination were calculated using conditional logistic regression, controlling for by underlying conditions.Results Pneumococcal vaccination did not alter significantly the risk of overall pneumococcal pneumonia [adjusted OR: 0.71; 95% confidence interval (CI): 0.37–1.39]. Point estimates of vaccine effectiveness was the maximum against bacteremic pneumococcal pneumonia due to vaccine-serotypes, although neither reached statistical significance (adjusted OR: 0.51; 95% CI: 0.03–8.19). Vaccination pointed to a smaller benefit against nonbacteremic pneumococcal pneumonia (adjusted OR: 0.66; 95% CI: 0.33–1.34). Pneumococcal vaccination was associated with a non-statistically significant reduction in the risk of all pneumococcal pneumonia among persons 75 y or older (adjusted OR: 0.45; 95% CI: 0.16–1.27), but no apparent protective effect emerged among people 50–74 y (adjusted OR: 1.48; 95% CI: 0.62–3.56).Conclusions The effectiveness of the PPV-23 in preventing pneumonia among patients with chronic pulmonary disease is uncertain. Our results point to PPV-23 having little or null effect against pneumococcal pneumonia in such patients, but definitive conclusions cannot be established based on our data.

The Role of IL-17 in the Association between Pneumococcal Pneumonia and Allergic Sensitization.

Interleukin- (IL-) 17 is important in the development of asthma and host defense against pneumococci. We determined the role of IL-17 in the risk of pneumococcal pneumonia. We challenged mice intranasally with a bioluminescent Streptococcus pneumoniae strain after sensitization and challenge with ovalbumin (OVA). We measured the levels of cytokines, including IL-17 (pg/mL), in the lung homogenate in experimental mice with and without OVA sensitization/challenge, as well as those with and without pneumococcal pneumonia. IL-17 levels were significantly lower in OVA-sensitized/challenged mice (9.69 ± 1.49), compared to the control mice (20.92 ± 1.82, P < 0.001). In our overall analysis, including IL-4 and IL-17 levels and OVA sensitization/challenge, IL-4 levels (OR: 81.9, 95%CI: 4.3–1523 per increment of 1.0 pg/mL, P = 0.003) were more significant than IL-17 levels (OR: 1.1, 95%CI: 1.03–1.17 per increment of 1.0 pg/mL, P = 0.003) in determining the risk of pneumococcal pneumonia. IL-17 levels result in a much smaller impact on the risk for pneumococcal pneumonia, compared to IL-4 levels.

Immune Function, Autoimmunity, and Selective Immunoprophylaxis in the Aged

Many changes occur in the immune system with age. The involution of the thymus plays a major role in immune senescence. Related to this event are the altered ratio of helper to suppressor T-lymphocyte subsets, decrease in immune response by both cell-mediated and humoral branches of the immune system, and increase in autoimmune activity. The clinical implications of these changes are the elderly person's increased susceptibility to infections such as pneumococcal pneumonia, influenza A, and tetanus as well as increased autoimmune activity, reflected by pernicious anemia. Other changes may be increased susceptibility to neoplasms and perhaps acceleration of the aging process. A high index of suspicion should be present for the diagnosis of pernicious anemia in the elderly population. Knowledge of the many autoantibodies that might be present without illness is important when evaluating for disease processes. The relationship of the senescent immune system to the aging process is still unknown. Investigations of this matter, as well as of the function of immune system components and their relationship to disease processes, are continuing. Most methods proposed for enhancing the immune system are still experimental. However, immunizations have been proved to be an effective means of reducing morbidity and mortality from certain infectious diseases in the elderly. Therefore, it is strongly recommended that all elderly persons who are at risk for pneumococcal pneumonia, influenza, and tetanus receive the proper immunizations.

Pharmacist-coordinated pneumonia and influenza vaccination program

High-risk candidates in an ambulatory-care center were identified and immunized against pneumococcal pneumonia and influenza in a program coordinated by a pharmacist. Patients determined to be at increased risk for pneumococcal pneumonia were notified by letter of the vaccination program and encouraged to participate. Participants were then screened by their health-care providers to determine whether they were candidates for the vaccination. Those who received the pneumococcal pneumonia vaccine were later urged to be immunized against influenza virus. Of 1593 patients selected as possible vaccine candidates, 474 received the pneumococcal vaccine and 397 received the influenza vaccine. No confirmed cases of pneumococcal pneumonia and only one case of flu-like syndrome developed among the immunized patients. Income from the program exceeded its cost, excluding the salaries of the center's employees. Substantial savings were projected from reduced future treatment costs. The pharmacist had initiated and coordinated a successful effort to increase vaccine use and decrease morbidity.