Hospital-Acquired Bloodstream Infections in Relation to Intensive Care Unit Stays During Hospitalization-A Population-Based Cohort Study.

Little is known about the clinical characteristics and pathogens causing hospital-acquired bloodstream infections (HA-BSIs) in relation to an intensive care unit (ICU) stay. Population-based cohort study, comprising 35% of the Danish population, 2009-2016. We derived four patient groups with first-time HA-BSIs: no ICU stay during the admission (non-ICU patients) and HA-BSI acquired before, in, or after an ICU stay (before-ICU, in-ICU, and after-ICU patients).

The increasing incidence and mortality of bacteremia in Denmark from 2010 to 2022: a population-based nationwide cohort study.

Objectives: An increasing incidence of positive blood cultures has been reported in several countries. This represents an important challenge for public health due to the large number of hospital admissions with high mortality among these patients. This study aims to characterize the epidemiology and mortality associated with positive blood cultures.

Mandatory surveillance of bacteremia conducted by automated monitoring.

Except for a few countries, comprehensive all-cause surveillance for bacteremia is not part of mandatory routine public health surveillance. We argue that time has come to include automated surveillance for bacteremia in the national surveillance systems, and explore diverse approaches and challenges in establishing bacteremia monitoring. Assessed against proposed criteria, surveillance for bacteremia should be given high priority.

No associations between neuroborreliosis in children and psychiatric neurodevelopmental disorders: a nationwide, population-based, matched cohort study.

Background: It has been suggested that neuroborreliosis in children can manifest as psychiatric neurodevelopmental disorders or cause long-term neurodevelopmental sequelae. However, previous studies were limited by size and design.

Methods: We performed a nationwide, population-based, matched cohort study in Denmark between 1995 and 2021.

Susceptibility to and severity of SARS-CoV-2 infection according to prescription drug use-an observational study of 46,506 Danish healthcare workers.

It is not well investigated whether exposure to specific drug classes is associated with COVID-19. We investigated the risk of SARS-CoV-2 infection and severe COVID-19 among healthcare workers according to prescription drug use. We conducted an observational study among Danish healthcare workers.

Risk of psychiatric neurodevelopmental disorders after meningitis in childhood: a nationwide, population-based cohort study.

Background: Few studies have investigated the risk of psychiatric neurodevelopmental disorders (PNDD) after childhood meningitis.

Methods: Nationwide population-based cohort study (Denmark, 1995-2021) of children with positive cerebrospinal fluid for bacteria or enterovirus, stratified on age as young infants (0 to <90 days,  = 637) or older children (≥90 days to <17 years,  = 1,218). We constructed a comparison cohort from the general population ( = 18,550), and cohorts of siblings of participants.

Healthcare-seeking behaviour preceding diagnosis of Lyme neuroborreliosis: population-based nationwide matched nested case-control study.

Objectives: To identify diagnostic opportunities, we investigated healthcare-seeking behaviour among patients with Lyme neuroborreliosis (LNB) within 28 weeks before diagnosis.

Methods: We conducted a population-based, nationwide matched nested case-control study (Denmark, 2009-2021). As cases, we included all Danish residents with LNB (positive Borrelia burgdorferi intrathecal antibody index test and cerebrospinal fluid pleocytosis).

Colorectal cancer and association with anaerobic bacteraemia: A Danish nationwide population-based cohort study.

Objectives: We aimed to identify specific anaerobic bacteria causing bacteraemia and a subsequent diagnosis of colorectal cancer.

Methods: A nationwide population-based cohort study, which included all episodes of defined specific anaerobic bacteraemia from 2010 (5,534,738 inhabitants) through 2020 (5,822,763 inhabitants) and all cases of colorectal cancer diagnosed from 2010 through 2021 in Denmark. We calculated the incidence and risk of colorectal cancer after bacteraemia with specific anaerobic bacteria using Escherichia coli bacteraemia as reference.

Obtainment of prescribed analgesics among patients with Lyme neuroborreliosis; a nationwide, population-based matched cohort study.

Background: Radicular pain is the most predominant symptom among adults with Lyme neuroborreliosis (LNB) but the duration preceding and following diagnosis remains unknown. We aimed to investigate whether patients with LNB have increased obtainment of analgesics before and after diagnosis and for how long.

Methods: We performed a nationwide, population-based, matched cohort study (2009-2021).

Comparative epidemiology of bacteraemia in two ageing populations: Singapore and Denmark.

Burden of bacteraemia is rising due to increased average life expectancy in developed countries. This study aimed to compare the epidemiology and outcomes of bacteraemia in two similarly ageing populations with different ethnicities in Singapore and Denmark. Historical cohorts from the second largest acute-care hospital in Singapore and in the hospitals of two Danish regions included patients aged 15 and above who were admitted from 1 January 2006 to 31 December 2016 with at least 1 day of hospital stay and a pathogenic organism identified.

Risk of heart failure among individuals tested for Borrelia burgdorferi sensu lato antibodies, and serum Borrelia burgdorferi sensu lato seropositive individuals; a nationwide population-based, registry-based matched cohort study.

Background: Lyme borreliosis is a tick-borne disease caused by the bacterium Borrelia burgdorferi (Bb) sensu lato complex. Previous studies have suggested an association between Lyme borreliosis and heart failure, which have been suggested to be a possible manifestation of Lyme carditis. We aimed to investigate the risk of heart failure among individuals tested for serum Bb antibodies, and serum Bb seropositive individuals.

Inhaled corticosteroids and in outpatients with chronic obstructive pulmonary disease: a retrospective cohort study.

Objectives: Inhaled corticosteroids (ICS) are widely used in patients with chronic obstructive pulmonary disease (COPD). However, ICS are associated with an increased risk of adverse effects.We aimed to determine whether an association between a lower respiratory tract culture with and increasing ICS dosing in patients with COPD exists.

Risk of cardiac conduction disorders, and pacemaker implantations among individuals tested for serum Borrelia burgdorferi antibodies, a nationwide, matched, population-based cohort study.

Objectives: To investigate the short- and long-term risks of atrioventricular block and other cardiac conduction disorders associated with being tested for Borrelia burgdorferi (Bb) antibodies or Bb seropositivity as measures of confounding by indication and Bb infection, respectively.

Methods: We performed a nationwide population-based matched cohort study (Denmark, 1993-2021). We included 52 200 Bb-seropositive individuals (stratified as only Bb-IgM-seropositive [n = 26 103], only Bb-IgG-seropositive [n = 18 698], and Bb-IgM-and-IgG-seropositive [n = 7399]) and two age- and sex-matched comparison cohorts: 104 400 Bb-seronegative individuals and 261 000 population controls.

Characteristics and long-term prognosis of Danish residents with a positive intrathecal antibody index test for herpes simplex virus or varicella-zoster virus compared with individuals with a positive cerebrospinal fluid PCR: a nationwide cohort study.

Objectives: We compared characteristics and outcomes of individuals who in the cerebrospinal fluid (CSF) were positive for herpes simplex virus (HSV) or varicella-zoster virus (VZV)-intrathecal antibody index test ([AI]-positive) vs. individuals who were PCR-positive for HSV type 1 (HSV1), type 2 (HSV2), and for VZV.

Methods: Nationwide cohort study of all Danish residents with positive CSF-AI or -PCR for HSV or VZV (1995-2021).

Detection of infections by computerized capture of peaks in longitudinally measured C-reactive protein levels.

We developed four algorithms for the automatic capture of C-reactive protein (CRP) peaks in 296 adult patients with acute myeloid leukemia who had bloodstream infection (BSI) episodes, negative blood cultures (BCs) or possible infections where no BCs were performed. The algorithms detected CRP peaks for 418-446 of the 586 documented BSI episodes (71.3-76.

Risk of haematologic cancers among individuals tested for Borrelia burgdorferi antibodies, and Borrelia burgdorferi seropositive individuals: a nationwide population-based matched cohort study.

Objectives: In a nationwide, matched cohort study, we aimed to investigate risks of haematologic cancers among individuals tested for Borrelia burgdorferi (Bb) antibodies, and among serum Bb seropositive individuals.

Methods: We identified all Bb seropositive individuals in Denmark (1993-2020) (n = 52 200) and constructed two age- and sex-matched comparison cohorts: (a) Bb seronegative controls (n = 104 400) and (b) background population controls (n = 261 000). We calculated short-term OR (aOR) (<1 month of study inclusion), and long-term hazard ratios (aHR) (>1 month after study inclusion) adjusted for age and sex.

Exploring the dynamics of Borrelia burgdorferi sensu lato antibodies-a registry-based study on laboratory data from Sweden and Denmark.

Objectives: Lyme borreliosis (LB) is the most common tick-transmitted infection in the northern hemisphere and is caused by bacteria in the Borrelia burgdorferi sensu lato (Bbsl)-complex. The diagnosis is partially based on serology, and clinicians often take follow-up serum samples to look for seroconversion or an increase in IgG-antibody levels. In this registry-based study, we proposed a method for determining actual changes in IgG and examined antibody reactivity and decay.

Mortality and exacerbations associated with Stenotrophomonas maltophilia in chronic obstructive pulmonary disease. A regional cohort study of 22,689 outpatients.

Objectives: The clinical significance of Stenotrophomonas maltophilia in patients with COPD is poorly understood. We aimed to determine whether a lower respiratory tract culture positive for S. maltophilia in COPD patients was independently associated with increased risk of death and hospitalisation for exacerbation of COPD.

Inhaled corticosteroids and risk of lower respiratory tract infection with in patients with chronic obstructive pulmonary disease.

Background: Use of inhaled corticosteroids (ICS) is common in patients with chronic obstructive pulmonary disease (COPD) and has been associated with an increased risk of pneumonia. is one of the most common bacterial causes of infectious exacerbation in COPD. Currently, to our knowledge, no studies have investigated if ICS increases the risk of lower respiratory tract infection with in patients with COPD.

Increase in invasive group A streptococcal infections and emergence of novel, rapidly expanding sub-lineage of the virulent M1 clone, Denmark, 2023.

A highly virulent sub-lineage of the M1 clone has been rapidly expanding throughout Denmark since late 2022 and now accounts for 30% of the new invasive group A streptococcal infections. We aimed to investigate whether a shift in variant composition can account for the high incidence rates observed over winter 2022/23, or if these are better explained by the impact of COVID-19-related restrictions on population immunity and carriage of group A .

First molecular documented case of a rarely reported parasite: Plasmodium knowlesi infection in Denmark in a traveller returning from Malaysian Borneo.

Plasmodium knowlesi has been reported as an emerging infection throughout the Southeast Asian region, especially in the Malaysian state of Sabah, where it accounts for the majority of the malaria cases reported. This is in contrast to Europe, where imported P. knowlesi is a rarely reported infection.

Inhaled Corticosteroids in Patients with Chronic Obstructive Pulmonary Disease and Risk of Acquiring Infection. A Multiregional Epidemiological Study.

Background: Inhaled corticosteroids (ICS) are associated with an increased risk of clinical pneumonia among patients with chronic obstructive pulmonary disease (COPD). It is unknown whether the risk of microbiologically verified pneumonia such as pneumococcal pneumonia is increased in ICS users.

Methods: The study population consists of all COPD patients followed in outpatient clinics in eastern Denmark during 2010-2017.

Use of Inhaled Corticosteroids and Risk of Acquiring in Patients with Chronic Obstructive Pulmonary Disease.

Background: Inhaled corticosteroids (ICS) are widely used in chronic obstructive pulmonary disease (COPD), despite the known risk of severe adverse effects including pulmonary infections. Research Question: Our study investigates the risk of acquiring a positive Haemophilus influenzae airway culture with use of ICS in outpatients with COPD. Study Design and Methods: We conducted an epidemiological cohort study using data from 1 January 2010 to 19 February 2018, including 21,218 outpatients with COPD in Denmark.

The diagnostic value of serum Borrelia burgdorferi antibodies and seroconversion after Lyme neuroborreliosis, a nationwide observational study.

Objectives: Clinical guidelines disagree on the diagnostic usefulness of Borrelia burgdorferi (Bb) serum antibodies (serum-Bb) in investigation of Lyme neuroborreliosis (LNB). We investigated the association between serum-Bb and Bb intrathecal antibody index (Bb-AI) and rates of seroconversion and seroreversion after LNB.

Methods: Danish residents who had a Bb-AI and corresponding serum-Bb measured between 1994 and 2020 were identified at all Danish departments of clinical microbiology.