Changes in the epidemiology of pneumococcal bacteremia in a Swiss university hospital during a 15-year period, 1986-2000

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.

Independent influence of negative blood cultures and bloodstream infections on in-hospital mortality

Background

The independent influence of blood culture testing and bloodstream infection (BSI) on hospital mortality is unclear.

Methods

We included all adults treated in non-psychiatric services at our hospital between 2004 and 2011. We identified all blood cultures and their results to determine the independent association of blood culture testing and BSI on death in hospital using proportional hazards modeling that adjusted for important covariates.

Results

Of 297 070 hospitalizations, 48 423 had negative blood cultures and 5274 had BSI. 12 529 (4.2%) died in hospital. Compared to those without blood cultures, culture-negative patients and those with BSI were sicker. Culture-negative patients had a significantly increased risk of death in hospital (adjusted hazard ratio [HR] ranging between 3.1 and 4.4 depending on admission urgency, extent of comorbidities, and whether the blood culture was taken in the intensive care unit). Patients with BSI had a significantly increased risk of death (adj-HR ranging between 3.8 and 24.3] that was significantly higher when BSI was: diagnosed within the first hospital day; polymicrobial; in patients who were exposed to immunosuppressants or were neutropenic; or due to Clostridial and Candidal organisms. Death risk in culture negative and bloodstream infection patients decreased significantly with time.

Conclusions

Risk of death in hospital is independently increased both in patients with negative blood cultures and further in those with bloodstream infection. Death risk associated with bloodstream infections varied by the patient’s immune status and the causative microorganism.

Pneumococcal vertebral osteomyelitis at three teaching hospitals in Japan, 2003-2011: analysis of 14 cases and a review of the literature

BACKGROUND

Pneumococcal vertebral osteomyelitis (PVO) is a rare disease whose clinical characteristics have not been clarified. This study aimed to investigate the clinical features and outcomes of patients with PVO.

METHODS

We retrospectively evaluated all adult patients diagnosed with PVO at three teaching hospitals in Japan from January 2003 to December 2011. All cases were identified through a review of the medical records of patients with invasive pneumococcal disease (IPD).

RESULTS

Among 208 patients with IPD, we identified 14 with PVO (6.4%; 95% CI, 3.5-10%). All 14 patients (nine male, five female; median age 69 years) had acquired PVO outside the hospital and had no recent history of an invasive procedure or back injury. Five patients (36%) had diabetes mellitus, and four (29%) had heavy alcohol intake. Fever (n = 13; 93%) or back pain/neck pain (n = 12; 86%) were present in most patients. The lumbar spine was affected in nine patients (64%) but the cervical spine was the site of infection in four patients (29%). All patients except one had a positive blood culture for Streptococcus pneumoniae, and there were no distant infected sites in most patients (n = 10; 71%). Intravenous beta-lactam therapy was initiated within 1 week after the onset of symptoms in 11 patients (79%). No patients died within 30 days, but one patient died from aspiration pneumonia on day 37 after admission.

CONCLUSIONS

PVO was relatively common among adult patients with IPD, and mortality was low in this study. S. pneumoniae may be the causative pathogen of vertebral osteomyelitis, especially among community-onset cases without a history of invasive procedures or back injury.

Pneumococcus

Pneumococcus is one of the most common bacterial pathogens encountered in medicine. This article summarizes the risk factors, pathogenesis, treatment, and prevention of the spectrum of disease caused by pneumococcus with particular emphasis on antibiotic resistance as well as immunization. This information is useful for physicians caring for patients both as inpatients and outpatients as well as for those concerned with public health and disease prevention.

Updated antibiotic resistance and clinical spectrum of infections caused by Streptococcus pneumoniae in Taiwan: Emphasis on risk factors for penicillin nonsusceptibilities

BACKGROUND/PURPOSE(S)

Streptococcus pneumoniae is one of the leading pathogens causing community-acquired infection with high mortality rates in elderly patients. Emerging antibiotic resistance was found in past decades. Continuous surveillance to monitor changes in antibiotic resistance of S. pneumoniae and associated risk factors are important clinical issues.

METHODS

Isolates of S. pneumoniae collected from six hospitals participating in the Taiwan Surveillance of Antimicrobial Resistance (TSAR) program III (2002) - VI (2008) were enrolled in this study. Bacterial susceptibilities were determined by minimum inhibitory concentration. The clinical data of source patients were collected retrospectively.

RESULTS

A total of 330 nonduplicate S. pneumoniae isolates were enrolled in this study. Sputum was the most common specimen source, followed by pus. The mean age of the source patients was 38 years among these 330 patients, and 247 had various infections caused by S. pneumoniae. The overall in-hospital mortality rate was 6% and most (60%)of the mortality occurred in patients older than 65 years. The mortality rates among the patients age 65 years and older and those age 5 years and younger were 12.9% (9 of 70) and 2.4% (2 of 83), respectively. The rates of nonsusceptibility to penicillin by the meningitis criteria (PNSP-M) were 69.0% in 2002, 81.0% in 2004, 73.7% in 2006, and 74.5% in 2008. Resistance to erythromycin and trimethoprim/sulfamethoxazole remained high. Using multivariate analysis, patients with PNSP isolates were more likely to have a history of antibiotic exposure within the previous 15 days compared with patients with penicillin-susceptible (PSSP) isolates (nonmeningitis criteria: 29.70% vs. 18.34%, p = 0.0288; meningitis criteria: 25.30% vs. 9.88%, p = 0.006). Shock at presentation was the risk factor for in-hospital mortality.

CONCLUSION

Our study demonstrated that the rates of penicillin nonsusceptibility among S. pneumoniae remained high in Taiwan during the study period. Previous antibiotic exposure was the only risk factor for subsequent acquisition of penicillin- nonsusceptible S. pneumoniae compared with penicillin-susceptible S. pneumoniae. Judicious antibiotic use is important to control the spread of drug nonsusceptible S. pneumoniae.

Pneumococcus infections: is the burden still as heavy?

The death rate of invasive pneumococcal infections decreased by 100 fold in one century. This tremendous improvement was due mainly to antibiotic use and multiple attempts at antipneumococcal vaccinations; thus, this was true only for developed countries. However, in France, the incidence has increased, over the last 10 years, in all age classes except for children vaccinated by the heptavalent pneumococcal conjugate vaccine. The incidence of these infections remains high, when associated to some risk factors such as HIV infection, malignant blood diseases, solid cancers, bronchial diseases, or alcohol abuse. The pneumococcal vaccine should be prescribed first to patients with those risk factors. A change of serotypes distribution has been observed in children with a decrease of vaccine serotypes and predominance of related or non-vaccine serotypes. This reflects the effectiveness of vaccination and the need of to regularly update the vaccine. Thus, pneumococcal infections have been increasing and vaccination should be more widely proposed.

Initial management of and outcome in patients with pneumococcal bacteremia: a retrospective study at a Swiss university hospital, 2003-2009

PURPOSE

The aim of this quality control study was to assess the time to initial diagnostic procedures and the time to the first dose of antibiotics in patients with pneumococcal bacteremia, and to investigate whether the timeliness of these interventions influenced outcome.

METHODS

We retrospectively studied patient characteristics, chronological sequence of diagnostic and therapeutic steps, and the course of disease of all patients with pneumococcal bacteremia at a Swiss university hospital between 2003 and 2009, and we analyzed associations between these factors and the length of hospital stay (LOS) and mortality.

RESULTS

A total of 102 episodes of pneumococcal bacteremia in 98 patients were analyzed, of whom 15.7% died during hospitalization. The median time (interquartile range [IQR]) to the first antibiotic dose was 4.0 (2.0-5.9) h, and the median times (IQR]) to blood cultures, chest radiograph, lumbar puncture, and brain computed tomography (CT) scan or magnetic resonance imaging (MRI) were 1.4 (0.5-3.3), 2.5 (1.2-4.2), 4.2 (2.7-7.2), and 2.3 (0.6-6.2) h, respectively. The time to diagnostic procedures and therapy were not associated with LOS or death. Risk factors for death in the univariable analysis were: Charlson comorbidity index [odds ratio [OR] (95% confidence interval) per unit increase, 1.3 (1.1-1.6)], neutropenia [OR 10.1 (2.0-51.0)], human immunodeficiency virus (HIV) infection [OR 3.9 (1.1-13.8)], chronic respiratory disease [OR 4.4 (1.2-16.0)], chronic liver disease [OR 3.2 (1.0-9.7)], smoking [OR 3.8 (1.1-13.5)], injection drug use [OR 9.7 (1.5-63.7)], and antibiotic therapy within 6 months before admission [OR 4.0 (1.3-12.5)]. The multivariable analysis revealed age >60 years (P = 0.048) and alcoholism (P = 0.009) as risks for prolonged LOS.

CONCLUSIONS

The outcome of pneumococcal bacteremia may be more influenced by patient characteristics than by minor differences in the timeliness of initial diagnostic and therapeutic measures within the first several hours after hospital admission.

Risk factor analysis for pneumococcal meningitis in adults with invasive pneumococcal infection

Pneumococcal meningitis is a subgroup of invasive pneumococcal disease with a case-fatality rate of up to 30% and long-term sequelae in more than 50% of cases in adults in developed countries. We aimed to determine risk factors for this particular form of pneumococcal disease. We conducted a prospective population-based laboratory study of invasive pneumococcal disease in adults in North-Rhine-Westphalia, Germany from February 2001 to August 2006. All isolates underwent serotyping and susceptibility testing at the National Reference Centre for Streptococci in Aachen, Germany. Data were analysed using multiple linear regression. A total of 1043 isolates from bacteraemia and 131 isolates from meningitis were included into the study. Serotype 23F and being female were independent risk factors for pneumococcal meningitis. Being ⩾60 years and serotype 1 were associated with a reduced odds ratio. Season, penicillin and macrolide resistance were not statistically associated with CNS involvement.

An artificial intelligence tool to predict fluid requirement in the intensive care unit: a proof-of-concept study

Introduction

The goal of personalised medicine in the intensive care unit (ICU) is to predict which diagnostic tests, monitoring interventions and treatments translate to improved outcomes given the variation between patients. Unfortunately, processes such as gene transcription and drug metabolism are dynamic in the critically ill; that is, information obtained during static non-diseased conditions may have limited applicability. We propose an alternative way of personalising medicine in the ICU on a real-time basis using information derived from the application of artificial intelligence on a high-resolution database. Calculation of maintenance fluid requirement at the height of systemic inflammatory response was selected to investigate the feasibility of this approach.

Methods

The Multi-parameter Intelligent Monitoring for Intensive Care II (MIMIC II) is a database of patients admitted to the Beth Israel Deaconess Medical Center ICU in Boston. Patients who were on vasopressors for more than six hours during the first 24 hours of admission were identified from the database. Demographic and physiological variables that might affect fluid requirement or reflect the intravascular volume during the first 24 hours in the ICU were extracted from the database. The outcome to be predicted is the total amount of fluid given during the second 24 hours in the ICU, including all the fluid boluses administered.

Results

We represented the variables by learning a Bayesian network from the underlying data. Using 10-fold cross-validation repeated 100 times, the accuracy of the model in predicting the outcome is 77.8%. The network generated has a threshold Bayes factor of seven representing the posterior probability of the model given the observed data. This Bayes factor translates into p < 0.05 assuming a Gaussian distribution of the variables.

Conclusions

Based on the model, the probability that a patient would require a certain range of fluid on day two can be predicted. In the presence of a larger database, analysis may be limited to patients with identical clinical presentation, demographic factors, co-morbidities, current physiological data and those who did not develop complications as a result of fluid administration. By better predicting maintenance fluid requirements based on the previous day's physiological variables, one might be able to prevent hypotensive episodes requiring fluid boluses during the course of the following day.

The evidence for using conjugate vaccines to protect HIV-infected children against pneumococcal disease

Pneumococcal conjugate vaccines (PCVs) are a potentially useful complement to existing treatment strategies in HIV-infected children, for whom pneumococcal infections are common and serious. This Review summarises available data on the burden of pneumococcal disease and the safety and efficacy of PCVs in HIV-infected children. The data demonstrate that children with HIV have significantly increased risk of pneumococcal disease compared with uninfected children; the serotypes included in currently licensed or near-licensure conjugate vaccines include most serotypes that cause invasive pneumococcal disease (IPD) in HIV-infected children and adults; PCVs provide substantial protection against IPD and clinical pneumonia when given to HIV-infected infants; and HIV-infected adults gain an indirect benefit when children in the community are vaccinated. PCV should be considered as an important intervention for improving the lives of HIV-infected children.

Epidemiology of invasive pneumococcal disease in Kumasi, Ghana

There are few data on the epidemiology of invasive pneumococcal disease in Africa. We undertook a prospective study of these infections in Kumasi, Ghana, collecting clinical data on all patients with laboratory-confirmed pneumococcal meningitis, pneumonia or systemic sepsis associated with bacteraemia. A total of 140 cases were identified in the period from January 2002 to April 2005. The disease was most prevalent among patients <5 years of age and immediately following the peak of the harmattan wind. The majority of patients were treated with a combination of antibiotics, in part reflecting concerns regarding antibiotic resistance. Mortality was high (47%), with no evidence of an improved prognosis compared with earlier studies in the region. Although most isolates of pneumococci were resistant to tetracyclines and co-trimoxazole, there was no high-level resistance to penicillin and only 12% of isolates showed intermediate level resistance. Serotype 1 was the most common serotype (36%), whilst intermediate-level penicillin resistance was associated with serotype 14. Theoretical coverage by existing 7-, 9-, 11- and 23-valent vaccines was 26%, 63%, 64% and 76%, respectively. Vaccination may improve control of pneumococcal disease in Ghana, although modified vaccine formulations are required for local use.

Der Wert der klinischen Infektiologie

Infectious diseases specialists are involved in patient care mostly regarding patients with severe infections in complex situations. Morbidity and mortality of severe infections such as sepsis has been significantly reduced during past years and decades. Prognosis of severe infections is dependent upon timely and correct diagnosis and appropriate therapy. The diagnostic and therapeutic approach is often invasive and interdisciplinary. Importantly, thoughtful use of antibiotics may increase its effectiveness, reduce antibiotic use and occurrence of bacterial resistance and increase cost effectiveness. Hence, antibiotic management and stewardship has become more and more the focus of work. This article highlights the clinical work of infectious diseases specialists in an interdisciplinary setting and describes there value to patients and hospitals.