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

The past, present and future of polymicrobial infection research: Modelling, eavesdropping, terraforming and other stories

Over the last two centuries, great advances have been made in microbiology as a discipline. Much of this progress has come about as a consequence of studying the growth and physiology of individual microbial species in well-defined laboratory media; so-called "axenic growth". However, in the real world, microbes rarely live in such "splendid isolation" (to paraphrase Foster) and more often-than-not, share the niche with a plethora of co-habitants. The resulting interactions between species (and even between kingdoms) are only very poorly understood, both on a theoretical and experimental level. Nevertheless, the last few years have seen significant progress, and in this review, we assess the importance of polymicrobial infections, and show how improved experimental traction is advancing our understanding of these. A particular focus is on developments that are allowing us to capture the key features of polymicrobial infection scenarios, especially as those associated with the human airways (both healthy and diseased).

Nano-Biotechnology for Bacteria Identification and Potent Anti-bacterial Properties: A Review of Current State of the Art

Sepsis is a critical disease caused by the abrupt increase of bacteria in human blood, which subsequently causes a cytokine storm. Early identification of bacteria is critical to treating a patient with proper antibiotics to avoid sepsis. However, conventional culture-based identification takes a long time. Polymerase chain reaction (PCR) is not so successful because of the complexity and similarity in the genome sequence of some bacterial species, making it difficult to design primers and thus less suitable for rapid bacterial identification. To address these issues, several new technologies have been developed. Recent advances in nanotechnology have shown great potential for fast and accurate bacterial identification. The most promising strategy in nanotechnology involves the use of nanoparticles, which has led to the advancement of highly specific and sensitive biosensors capable of detecting and identifying bacteria even at low concentrations in very little time. The primary drawback of conventional antibiotics is the potential for antimicrobial resistance, which can lead to the development of superbacteria, making them difficult to treat. The incorporation of diverse nanomaterials and designs of nanomaterials has been utilized to kill bacteria efficiently. Nanomaterials with distinct physicochemical properties, such as optical and magnetic properties, including plasmonic and magnetic nanoparticles, have been extensively studied for their potential to efficiently kill bacteria. In this review, we are emphasizing the recent advances in nano-biotechnologies for bacterial identification and anti-bacterial properties. The basic principles of new technologies, as well as their future challenges, have been discussed.

Immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine administered in a prime-boost regimen among Chinese infants: a randomized, double blind phase III clinical trial

This study aimed to evaluate the immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine (PCV13). In total, 1200 infants were randomized into two groups with a 1:1 allocation and received a three-dose series of tested PCV13 or control PCV13 at ages 2, 4 and 6 months, respectively, and a booster dose at 12-15 months. Blood samples were collected before and 30 days after primary and booster vaccination. Serotype-specific antibodies were measured using ELISA for immunoglobulin G (IgG) and OPA for functional antibodies. Safety data were collected for 30 days after each inoculation. Results showed that post primary vaccination seropositive rates of all 13 serotypes except type 3 were not significantly different between two groups. The seropositive rate for type 3 in Group T was significantly higher than Group C (P < .0001). For all 13 serotypes except type 7 F, the GMCs in Group T were significantly higher than Group C. The GMC for type 7 F in Group T (P < .0009) was significantly lower than Group C. The frequencies of overall adverse events (P = .0064) and solicited adverse reactions (P = .0019) in Group T were significantly lower than Group C. Post booster vaccination, seropositive rates for all serotypes in Group T were 100.00%. For all serotypes except type 23 F, IgG GMCs in Group T were significantly higher than Group C. Totally, 21 subjects reported SAEs and all but one were considered irrelevant or probably irrelevant to vaccination. In conclusion, the tested PCV13 showed non-inferior immunogenicity and had a good safety profile compared with control vaccine.

Thyroid function and risk of bloodstream infections: Results from the Norwegian prospective population-based HUNT Study

OBJECTIVE

Previous studies on thyroid function and risk of infection is conflicting and often stem from intensive care cohorts were nonthyroidal illness syndrome (NTIS) may be present. The objective of this study was to identify the risk of bloodstream infections (BSI) and BSI-related mortality with thyroid-stimulating hormone (TSH) levels within the reference range in a general population.

DESIGN

Prospective follow-up.

PARTICIPANTS

The HUNT2 (1995-97) included 34,619 participants with information on TSH levels.

MEASUREMENTS

Hazard ratios (HRs) with 95% confidence interval (CI) confirmed BSIs and BSI-related mortality until 2011.

RESULTS

During a median follow-up of 14.5 years, 1179 experienced at least one episode of BSI and 208 died within 30 days after a BSI. TSH levels within the reference range of 0.5-4.5 mU/L were not associated with the risk of first-time BSI, with an HR of 0.97 (95% CI: 0.90-1.04) per mU/L. Stratified by baseline age < or ≥65 years, TSH was inversely associated with the risk of BSI (HR: 0.88; 95% CI: 0.78-1.00 per mU/L) in the youngest age group only. Persons with any baseline thyroid disease had a 30% risk and the hyperthyroid subgroup a 57%, and hypothyroidism a 20% increased risk of BSI. TSH levels were not clearly associated with BSI mortality, but the HRs were imprecise due to few BSI-related deaths.

CONCLUSION

There was some evidence of a weak inverse association between TSH levels and the risk of BSI in persons below 65 years of age. The increased risk seen in persons with thyroid illness is probably explained by confounding by concurrent ill health.

Explaining sex differences in risk of bloodstream infections using mediation analysis in the population-based HUNT study in Norway

Previous studies indicate sex differences in incidence and severity of bloodstream infections (BSI). We examined the effect of sex on risk of BSI, BSI mortality, and BSI caused by the most common infecting bacteria. Using causal mediation analyses, we assessed if this effect is mediated by health behaviours (smoking, alcohol consumption), education, cardiovascular risk factors (systolic blood pressure, non-HDL cholesterol, body mass index) and selected comorbidities. This prospective study included 64,040 participants (46.8% men) in the population-based HUNT2 Survey (1995-1997) linked with hospital records in incident BSI. During median follow-up of 15.2 years, 1840 (2.9%) participants (51.3% men) experienced a BSI and 396 (0.6%) died (56.6% men). Men had 41% higher risk of first-time BSI (95% confidence interval (CI), 28-54%) than women. Together, health behaviours, education, cardiovascular risk factors and comorbidities mediated 34% of the excess risk of BSI observed in men. The HR of BSI mortality was 1.87 (95% CI 1.53-2.28), for BSI due to S. aureus 2.09 (1.28-2.54), S. pneumoniae 1.36 (1.05-1.76), E. coli 0.97 (0.84-1.13) in men vs women. This study shows that men have higher risk of BSI and BSI mortality than women. One-third of this effect was mediated by potential modifiable risk factors for incident BSI.

A Jack of All Trades: The Role of Pneumococcal Surface Protein A in the Pathogenesis of Streptococcus pneumoniae

Streptococcus pneumoniae (Spn), or the pneumococcus, is a Gram-positive bacterium that colonizes the upper airway. Spn is an opportunistic pathogen capable of life-threatening disease should it become established in the lungs, gain access to the bloodstream, or disseminate to vital organs including the central nervous system. Spn is encapsulated, allowing it to avoid phagocytosis, and current preventative measures against infection include polyvalent vaccines composed of capsular polysaccharide corresponding to its most prevalent serotypes. The pneumococcus also has a plethora of surface components that allow the bacteria to adhere to host cells, facilitate the evasion of the immune system, and obtain vital nutrients; one family of these are the choline-binding proteins (CBPs). Pneumococcal surface protein A (PspA) is one of the most abundant CBPs and confers protection against the host by inhibiting recognition by C-reactive protein and neutralizing the antimicrobial peptide lactoferricin. Recently our group has identified two new roles for PspA: binding to dying host cells via host-cell bound glyceraldehyde 3-phosphate dehydrogenase and co-opting of host lactate dehydrogenase to enhance lactate availability. These properties have been shown to influence Spn localization and enhance virulence in the lower airway, respectively. Herein, we review the impact of CBPs, and in particular PspA, on pneumococcal pathogenesis. We discuss the potential and limitations of using PspA as a conserved vaccine antigen in a conjugate vaccine formulation. PspA is a vital component of the pneumococcal virulence arsenal - therefore, understanding the molecular aspects of this protein is essential in understanding pneumococcal pathogenesis and utilizing PspA as a target for treating or preventing pneumococcal pneumonia.

Prognostic factors for mortality in invasive pneumococcal disease in adult: a system review and meta-analysis

Risk factors associated with mortality in invasive pneumococcal disease remain unclear. The present work is a meta-analysis of studies that enrolled only patients with invasive pneumococcal disease and reported on mortality. Potentially eligible reports were identified from PubMed, CHAHL, and Web of Science, comprising 26 reports in total. Overall mortality for invasive pneumococcal disease was reported as 20.8% (95% confidence interval (CI) 17.5–24%). Factors associated with mortality were age (odds ratio (OR) 3.04, 95% CI 2.5–3.68), nursing home (OR 1.62, 95% CI 1.13–2.32), nosocomial infection (OR 2.10, 95% CI 1.52–2.89), septic shock (OR 13.35, 95% CI 4.54–39.31), underlying chronic diseases (OR 2.34, 95% CI 1.78–3.09), solid organ tumor (OR 5.34, 95% CI 2.07–13.74), immunosuppressed status (OR 1.67, 95% CI 1.31–2.14), and alcohol abuse (OR 3.14, 95% CI 2.13–4.64). Mortality rates with invasive pneumococcal disease remained high, and these findings may help clinicians provide appropriate initial treatment for this disease.

Bacterial Interactions with Aspergillus fumigatus in the Immunocompromised Lung

The immunocompromised airways are susceptible to infections caused by a range of pathogens which increases the opportunity for polymicrobial interactions to occur. Pseudomonas aeruginosa and Staphylococcus aureus are the predominant causes of pulmonary infection for individuals with respiratory disorders such as cystic fibrosis (CF). The spore-forming fungus Aspergillus fumigatus, is most frequently isolated with P. aeruginosa, and co-infection results in poor outcomes for patients. It is therefore clinically important to understand how these pathogens interact with each other and how such interactions may contribute to disease progression so that appropriate therapeutic strategies may be developed. Despite its persistence in the airways throughout the life of a patient, A. fumigatus rarely becomes the dominant pathogen. In vitro interaction studies have revealed remarkable insights into the molecular mechanisms that drive agonistic and antagonistic interactions that occur between A. fumigatus and pulmonary bacterial pathogens such as P. aeruginosa. Crucially, these studies demonstrate that although bacteria may predominate in a competitive environment, A. fumigatus has the capacity to persist and contribute to disease.

Antimicrobial resistance in clinical bacterial isolates from horses in the UK

BACKGROUND

Surveillance of antimicrobial resistance (AMR) in horses is important to aid empirical treatment decisions and highlight emerging AMR threats.

OBJECTIVE

To describe the AMR patterns of common groups of bacteria from clinical submissions from horses in the UK during 2018, and to determine how this varies by sample site and type of submitting veterinary practice.

STUDY DESIGN

Prospective observational study.

METHODS

All data on bacterial culture and subsequent antimicrobial susceptibility testing (AST) collected in 2018 from six large equine diagnostic laboratories were included. Resistance patterns were analysed including resistance to 1 or 2 antimicrobial classes, multidrug resistance (MDR), extensively drug resistant (XDR), resistance to highest priority critically important antimicrobials and isolates where there was no readily available treatment for adult horses in the UK. Submitting practices were classified according to whether they treated referral cases or not (first opinion). Comparisons between proportions and resistance for each bacterial group and sample site was performed using Chi-squared (or Fisher's exact test).

RESULTS

A total of 6,018 bacterial isolates from 4,038 diagnostic submissions were included from respiratory (n = 1555), urogenital (n = 1,010), skin/hair/wound/abscess (n = 753), surgical site infection (SSI) /catheter-related-infection (CRI) /orthopaedic infections (n = 347) and unknown/'other' submissions (n = 373). There were 2,711 Gram-negative isolates and 3,307 Gram-positive isolates. Prevalence of MDR for E. coli was 31.7%, Staphylococcus spp. 25.3% and > 25% for the majority of bacterial isolates from SSI/CRI/orthopaedic submissions. For Enterococcus spp. there was no readily available treatment for adult horses in the UK in 30.2% of positive submissions. MDR was significantly higher from referral hospital than first opinion submissions for the majority of pathogens (except Actinobacillus spp. and Pasteurella spp. and β-haemolytic Streptococcus spp.).

MAIN LIMITATIONS

Since culture and susceptibility results are not systematic analyses based on harmonised methods, selection bias could impact the findings.

CONCLUSIONS

Ongoing surveillance is essential to understand emerging patterns of resistance. MDR is high in SSI/CRI/orthopaedic infections, which is important for hospital biosecurity and guiding treatment decisions. Harmonisation of diagnostic procedures and interpretation of results amongst veterinary laboratories will improve AMR surveillance and data comparison among laboratories.

Invasive Pneumococcal Disease in UK Children <1 Year of Age in the Post-13-Valent Pneumococcal Conjugate Vaccine Era: What Are the Risks Now?

BACKGROUND

Invasive pneumococcal disease (IPD) has declined significantly since the introduction of pneumococcal conjugate vaccines (PCVs). It is not known whether certain infant populations remain at higher risk of IPD in countries with established 13-valent PCV (PCV13) programs. We aimed to describe the epidemiology, clinical characteristics, serotype distribution, and outcomes of IPD in infants, and to estimate the relative risk of PCV13-type, non-PCV13-type, and overall IPD in premature infants compared to term infants during a 4-year period after the PCV13 program was established.

METHODS

This was a prospective, enhanced national surveillance of laboratory-confirmed IPD in England in infants aged <1 year diagnosed during 2013-2016.

RESULTS

There were 517 cases of IPD (incidence: 19/100000 infants). Incidence was significantly higher in premature infants compared with those born at term (49/100000 vs 17/100000; incidence rate ratio [IRR], 2.87; P < .001), with infants born before 28 weeks' gestation having the highest incidence (150/100000; IRR, 8.8; P < .001). Of the 454 IPD cases with serotyped isolates, most were caused by non-PCV13 serotypes (369 cases, 71.4%), with 85 cases (16.4%) due to PCV13 serotypes. There were 31 deaths (case fatality rate [CFR], 6.2% [95% confidence interval, 4.3%-8.6%]). Premature infants did not have a higher CFR than term infants (P = .62).

CONCLUSIONS

IPD incidence in infants remains lower than rates reported prior to PCV7 introduction in England. The risk of IPD remains significantly higher in premature infants compared to infants born at term, for both PCV13 and non-PCV13 serotypes. Any changes to the infant PCV13 immunization schedule may disproportionally affect premature infants.

Septic Shock and Purpura Fulminans Due to Streptococcus pneumoniae Bacteremia in an Unvaccinated Immunocompetent Adult: Case Report and Review

BACKGROUND Despite proven efficacy of vaccinations against Streptococcus pneumoniae in preventing infection, only 70% of eligible individuals receive the vaccine in the United States. Pneumococcal bacteremia represents a form of invasive pneumococcal disease and is associated with high mortality, especially in immunocompromised patients and the elderly. Purpura fulminans is a rare complication and manifestation of disseminated intravascular coagulation and sepsis. It is exceedingly rare in the setting of pneumococcal bacteremia, particularly in immunocompetent individuals. CASE REPORT We report a generally healthy 67-year-old male with schizophrenia who refused pneumococcal vaccination. He had an intact and functional spleen with a functional immune system. The patient presented with fever and diarrhea. He subsequently progressed to develop purpura fulminans and septic shock due to S. pneumoniae bacteremia. Despite an extensive search for the primary source of infection, none could not be identified. Due to timely initiation of appropriate antibiotic therapy and aggressive supportive care in an intensive care unit, he recovered despite multi-organ failure that developed throughout his hospitalization. CONCLUSIONS We present a rare manifestation of a potentially preventable disease and emphasize the importance of pneumococcal vaccination in order to decrease the risk of developing invasive pneumococcal disease. Furthermore, we discuss etiology, diagnosis, differential diagnosis, and evidence-based management of purpura fulminans and invasive pneumococcal disease with a literature review. Purpura fulminans due to S. pneumoniae is exceedingly rare in immunocompetent patients and an unusual clinical manifestation of pneumococcal bacteremia.

Clinical characteristics of patients with severe sepsis and septic shock in relation to bacterial virulence of beta-hemolytic Streptococcus and Streptococcus pneumoniae

Aim

Combined detailed analysis of patient characteristics and treatment as well as bacterial virulence factors, which all play a central role in the cause of infections leading to severe illness, has not been reported. We aimed to describe the patient characteristics (Charlson comorbidity index [CCI]), treatment (3‐h bundle), and outcomes in relation to bacterial virulence of Streptococcus pneumoniae and beta‐hemolytic Streptococcus (BHS).

Methods

This sepsis primary study is part of the larger Focused Outcomes Research in Emergency Care in Acute Respiratory Distress Syndrome, Sepsis and Trauma (FORECAST) study, a multicenter, prospective cohort study. We included patients diagnosed with S. pneumoniae and BHS sepsis and examined virulence, defining the high‐virulence factor as follows: S. pneumoniae serotype 3, 31, 11A, 35F, and 17F; Streptococcus pyogenes, emm 1; Streptococcus agalactiae, III; and Streptococcus dysgalactiae ssp. equisimilis, emm typing pattern stG 6792. Included patients were divided into high and normal categories based on the virulence factor.

Results

Of 1,184 sepsis patients enrolled in the Japanese Association for Acute Medicine’s FORECAST study, 62 were included in the current study (29 cases with S. pneumoniae sepsis and 33 with BHS). The CCI and completion of a 3‐h bundle did not differ between normal and high virulence groups. Risk of 28‐day mortality was significantly higher for high‐virulence compared to normal‐virulence when adjusted for CCI and completion of a 3‐h bundle (Cox proportional hazards regression analysis, hazard ratio 3.848; 95% confidence interval, 1.108–13.370; P = 0.034).

Conclusion

The risk of 28‐day mortality was significantly higher for patients with high‐virulence compared to normal‐virulence bacteria.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Factors Associated With Severe Nonmeningitis Invasive Pneumococcal Disease in Adults in France

Background

In France, pneumococcal vaccination in adults is recommended for risk groups (chronic conditions/immunosuppression). We conducted a study on invasive pneumococcal disease (IPD) in adults to identify factors associated with disease severity and death.

Methods

We included IPD cases, excluding meningitis, from 25 acute care hospitals in 6 regions. We defined severe cases as those with shock or severe sepsis or intensive care unit admission/mechanical ventilation. We included deaths occurring within 30 days of hospitalization. Infectious disease specialists collected clinical/microbiological data on cases.

Results

During 2014–2017, 908 nonmeningitis IPD cases were diagnosed; 48% were severe, 84% had comorbidities, 21% died. Ninety percent of cases with comorbidities who previously sought health care were not vaccinated against pneumococcus. Compared with previously healthy cases, the risk of severe IPD increased from 20% (adjusted risk ratio [aRR], 1.2; 95% confidence interval [CI], 1.0–1.4) in cases with 1–2 chronic diseases to 30% (aRR, 1.3; 95% CI, 1.0–7.0) in those with >2 chronic diseases. Among risk groups, 13-valent pneumococcal conjugate vaccine (PCV13) serotypes and 23-valent pneumococcal polysaccharide vaccine (PPSV23) nonPCV13 serotypes were more likely to induce severe IPD compared with nonvaccine serotypes (aRR, 1.5; 95% CI, 1.3–1.9; aRR, 1.3; 95% CI, 1.0–1.5, respectively).

Conclusions

We observed a cumulative effect of concurrent comorbidities on severe IPD. Vaccine serotypes were more likely to induce severe IPD among risk groups. The missed opportunities for vaccination underscore the need to enhance vaccination in risk groups.

Pneumococcal sepsis requiring mechanical ventilation: Cohort study in 38 patients with rapid progression to septic shock

BACKGROUND

The aim was to study the course of severe pneumococcal sepsis in patients who rapidly developed septic shock with multiorgan failure.

METHODS

Combined retrospective and prospective cohort study of all patients with pneumococcal sepsis requiring mechanical ventilation admitted to our Medical Intensive Care Unit at Oslo University Hospital Ullevaal, during an 8-year period (01 January 2006 to 31 December 2013). The inclusion criteria were growth of Streptococcus pneumoniae in blood culture and respiratory failure treated with invasive mechanical ventilation.

RESULTS

Thirty-eight patients were included. Median age was 57 years (interquartile range 49-68, range 22-79). For 84% (32/38), it took <24 hours from the first medical evaluation until they were in septic shock. Initial clinical features were variable; none were treated with antibiotics before hospital admission. Median Sequential Organ Failure Assessment (SOFA) score at admission was 11 (range 1-15) and maximum 15 (range 5-22), all patients developed multiorgan failure. Mutilating complications were seen in 47% (18/38) of the patients: six with amputations, 11 had adverse neurological complications and one patient both. In-hospital mortality was 40% (15/38), 20% (8/38) survived with sequelae and 40% (15/38) returned to their habitual state. Poor outcome was associated with meningitis, disseminated intravascular coagulation, and gastrointestinal symptoms.

CONCLUSION

In this patient cohort with pneumococcal sepsis and respiratory failure rapid development of septic shock was seen in all cases, even in young healthy individuals. Initial clinical features were variable; none were treated with antibiotics before admission. Mortality was high (40%), as was morbidity with limb amputations and neurological complications.

Anxiety and Depression Symptoms in a General Population and Future Risk of Bloodstream Infection: The HUNT Study

OBJECTIVE

We examined whether anxiety and depression symptoms constitute increased risk of bloodstream infection (BSI), as a proxy for sepsis.

METHODS

A general population with self-reported anxiety and depression symptoms was followed prospectively for hospital-verified BSI. Using multivariable Cox regression analysis, we estimated hazard ratios (HR) with 95% confidence intervals (CI) of BSI and BSI mortality, with and without statistical adjustment for comorbidities, BMI, and life-style factors that may confound or mediate the associations.

RESULTS

During 14.8 years median follow-up of 59,301 individuals, 1578 (2.7%) experienced BSI and 328 (0.55%) participants died within 30 days after a BSI. Severe depression symptoms were associated with a 38% increased risk of BSI, adjusted for age, sex, and education (HR = 1.38, 95% CI = 1.10-1.73). The HR was attenuated to 1.23 (0.96-1.59) after adjustment for comorbidities and to 1.15 (0.86-1.53) after additional adjustment for BMI and life-style factors. For severe anxiety symptoms, the corresponding HRs were 1.48 (1.20-1.83), 1.35 (1.07-1.70), and 1.28 (0.99-1.64). Moderate symptoms of depression and anxiety were not associated with increased BSI risk. The analysis of BSI mortality yielded imprecise results but suggested an increased risk of BSI mortality in participants with moderate depression symptoms.

CONCLUSIONS

Severe depression and anxiety symptoms were associated with a moderately increased risk of BSI. The association may, at least in part, be confounded or mediated by comorbidities, BMI, and life-style. Future research should investigate whether interventions targeting improved BMI and life-style may reduce the risk of BSI and sepsis in people with depression and anxiety symptoms.

Venoarterial extracorporeal membrane oxygenation support for neonatal and pediatric refractory septic shock: more than 15 years of learning

The objective of the study was to report our institutional experience in the management of children and newborns with refractory septic shock who required venoarterial extracorporeal membrane oxygenation (VA ECMO) treatment, and to identify patient-and infection-related factors associated with mortality. This is a retrospective case series in an intensive care unit of a tertiary pediatric center. Inclusion criteria were patients ≤ 18 years old who underwent a VA ECMO due to a refractory septic shock due to circulatory collapse. Patient conditions and support immediately before ECMO, analytical and hemodynamic parameter evolution during ECMO, and post-canulation outcome data were collected. Twenty-one patients were included, 13 of them (65%) male. Nine were pediatric and 12 were newborns. Median septic shock duration prior to ECMO was 29.5 h (IQR, 20-46). Eleven patients (52.4%) suffered cardiac arrest (CA). Neonatal patients had worse Sepsis Organ Failure Assessment (SOFA) score, Oxygenation Index and PaO₂/FiO₂ ratio, blood gas analysis, lactate levels, and left ventricular ejection fraction compared to pediatric patients. Survival was 33.3% among pediatric patients (60% if we exclude pneumococcal cases) and 50% among newborns. Hours of sepsis evolution and mean airway pressure (MAP) prior to ECMO were significantly higher in the non-survivor group. CA was not a predictor of mortality. Streptococcus pneumoniae infection was a mortality risk factor. There was an improvement in survival during the second period, from 14.3 to 57.2%, related to shorter sepsis evolution before ECMO placement, better candidate selection, and greater ECMO support once the patient was placed.

CONCLUSION

Patients with refractory septic shock should be transferred precociously to a referral ECMO center. However, therapy should be used with caution in patients with vasoplegic pattern shock or S. pneumoniae sepsis. What is Known: • Children with refractory septic shock have significant mortality rates, and although ECMO is recommended, overall survival is low. • There are no studies regarding characteristics of infections as predictors of pediatric survival in ECMO. What is New: • Septic children should be transferred precociously to referral ECMO centers during the first hours if patients do not respond to conventional therapy. • Treatment should be used with caution in patients with vasoplegic pattern shock or S. pneumoniae sepsis.

Association of iron status with the risk of bloodstream infections: results from the prospective population-based HUNT Study in Norway

PURPOSE

As iron is essential for both immune function and microbial growth, alterations in iron status could influence the risk of infections. We assessed the associations of iron status with risk of bloodstream infections (BSIs) and BSI mortality.

METHODS

We measured serum iron, transferrin saturation (Tsat) and total iron-binding capacity (TIBC) in 61,852 participants in the population-based HUNT2 study (1995-97). Incident BSIs (1995-2011) were identified through linkage with the Mid-Norway Sepsis Register, which includes prospectively registered information on BSI from local and regional hospitals. We assessed the risk of a first-time BSI and BSI mortality with the iron indices using Cox proportional hazards regression analysis.

RESULTS

During a median follow-up of 14.8 years, 1738 individuals experienced at least one episode of BSI, and 370 died within 30 days after a BSI. In age- and sex-adjusted analyses, BSI risk was increased among participants with indices of iron deficiency, serum iron ≤ 2.5th percentile (HR 1.72, 95% CI 1.34-2.21), Tsat ≤ 2.5th percentile (HR 1.48, 95% CI 1.12-1.96) or TIBC ≥ 97.5th percentile (HR 1.46, 95% CI 1.06-2.01). The associations remained similar after adjusting for comorbidities and exclusion of BSI related to cancer, rheumatic illnesses and inflammatory bowel disease. BSI mortality showed similar associations.

CONCLUSION

Indices of severe iron deficiency are associated with an increased risk of a future BSI.

Associations of obesity and lifestyle with the risk and mortality of bloodstream infection in a general population: a 15-year follow-up of 64 027 individuals in the HUNT Study

Background

Bloodstream infections (BSI) cause considerable morbidity and mortality, and primary prevention should be a priority. Lifestyle factors are of particular interest since they represent a modifiable target.

Methods

We conducted a prospective cohort study among participants in the population-based Norwegian HUNT2 Survey, where 64 027 participants were followed from 1995-97 through 2011 by linkage to prospectively recorded information on BSI at local and regional hospitals. The exposures were: baseline body mass index (BMI) measurements; and self-reported smoking habits, leisure time physical activity and alcohol intake. The outcomes were hazard ratios (HR) of BSI and BSI mortality.

Results

During 810 453 person-years and median follow-up of 14.8 years, 1844 (2.9%) participants experienced at least one BSI and 396 (0.62%) died from BSI. Compared with normal weight participants (BMI 18.5-24.9 kg/m2), the age- and sex-adjusted risk of a first-time BSI was 31% [95% confidence interval (CI) 14-51%] higher at BMI 30.0-34.9 kg/m2, 87% (95% CI 50-135%) higher at BMI 35.0-39.9 kg/m2 and 210% (95% CI 117-341%) higher at BMI ≥ 40.0 kg/m2. The risk of BSI mortality was similarly increased. Compared with never-smokers, current smokers had 51% (95% CI 34-70%) and 75% (95% CI 34-129%) higher risks of BSI and BSI mortality, respectively. Physically inactive participants had 71% (95% CI 42-107%) and 108% (95% CI 37-216%) higher risks of BSI and BSI mortality, respectively, compared with the most physically active.

Conclusions

Obesity, smoking and physical inactivity carry increased risk of BSI and BSI mortality.

Burden of bloodstream infection in an area of Mid-Norway 2002-2013: a prospective population-based observational study

BACKGROUND

Studies from several countries indicate that the incidence and mortality of bloodstream infection (BSI) have been increasing over time.

METHODS

We studied the burden of disease and death related to BSI in a defined geographical area of Mid-Norway, where BSI episodes were prospectively recorded by the same microbiological department during 12 consecutive years. Death from BSI was defined as death within 30 days of BSI detection. Age and sex standardized incidence and mortality rates and case fatality rates were calculated.

RESULTS

Between 2002 and 2013, 1995 episodes of BSI in 1719 patients aged 16 to 99 years were included. The overall incidence of BSI was 215 per 100,000 person-years. The incidence increased exponentially with age, particularly in males. The incidence increased from 205 to 223 per 100,000 person-years from 2002-07 to 2008-13. Escherichia coli was the most frequently isolated infective agent, followed by Streptococcus pneumoniae and Staphylococcus aureus. The rate of S. pneumoniae BSI decreased over time in males (on average by 9.2% annually), but not in females. The total rate of BSI microbes with acquired resistance increased slightly over time, but did not exceed 2 episodes per 100,000 person-years. The mortality of BSI was 32 per 100,000 person-years, higher in males than in females (36 vs. 28 per 100,000 person-years) and was significantly higher in old age, particularly in males. The total BSI mortality was similar in the first and second halves of the study period, but the mortality of S. pneumoniae BSI decreased in males (15.0% annually). The crude case fatality decreased from the first to the second half of the study period (17.2% to 13.1%; p = 0.014). The rate of blood culture sampling increased more than twofold during the study period.

CONCLUSIONS

The mortality of BSI remained stable during 2002-2013. At the same time, BSI incidence increased and case fatality rate decreased, perhaps because an increased rate of blood culture sampling may have led to improved detection of milder BSI episodes. Very low, yet slightly increasing rates of microbes with acquired resistance were observed.

Early identification of sepsis in hospital inpatients by ward nurses increases 30-day survival

BACKGROUND

Systemic inflammatory response syndrome (SIRS) and sepsis are now frequently identified by observations of vital signs and detection of organ failure during triage in the emergency room. However, there is less focus on the effect on patient outcome with better observation and treatment at the ward level.

METHODS

This was a before-and-after intervention study in one emergency and community hospital within the Mid-Norway Sepsis Study catchment area. All patients with confirmed bloodstream infection have been prospectively registered continuously since 1994. Severity of sepsis, observation frequency of vital signs, treatment data, length of stay (LOS) in high dependency and intensive care units, and mortality were retrospectively registered from the patients' medical journals.

RESULTS

The post-intervention group (n = 409) were observed better and had higher odds of surviving 30 days (OR 2.7, 95 % CI 1.6, 4.6), lower probability of developing severe organ failure (0.7, 95 % CI 0.4, 0.9), and on average, 3.7 days (95 % CI 1.5, 5.9 days) shorter LOS than the pre-intervention group (n = 472).

CONCLUSIONS

In a cohort with stable mortality rates, early sepsis recognition by ward nurses may have reduced progression of disease and improved survival for patients in hospital with sepsis.