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Background: The COVID-19 pandemic placed considerable pressure on nursing homes, where care workers faced high workloads, uncertainty, and emotional strain while also being expected to implement extensive infection prevention and control (IPC) measures. Understanding how such everyday experiences affect adherence to IPC measures is essential for strengthening future guideline implementation and training. This study aimed to explore care workers’ experiences during the COVID-19 pandemic, with a focus on IPC measures and the realities of everyday work.

Methods: A qualitative descriptive design was used. Semi-structured interviews were conducted with 22 nurse assistants and care aides from 19 nursing homes in northern and southern Sweden (May–November 2023). The interviews were recorded, transcribed and then analyzed using inductive qualitative content analysis. The study was guided by the Consolidated Criteria for Reporting Qualitative Research.

Results: Three main categories captured nurse assistants’ and care aides’ experiences of how demanding everyday realities during the pandemic shaped adherence to IPC measures. (1) Organizational determinants highlighted the importance of leadership presence, clear information, and resource availability. (2) Individual aspects described how knowledge, beliefs, and physical discomfort influenced motivation to adhere. (3) Ethical issues related to IPC measures reflected tensions between IPC practices and meeting residents’ social and emotional needs.

Conclusions: This study highlights how leadership, resources, and knowledge supported IPC adherence, while personal beliefs and ethical implications complicated practice. Future preparedness requires policies that integrate organizational support with the human dimensions of care, ensuring that infection control and dignified care are mutually reinforced.

Background: Older adults (> 65 years) residing in long-term care facilities (LTCFs) are at elevated risk of severe outcomes from respiratory infections. Infections often remain undetected or present atypically in this population, leading to underdiagnosis. Our study aimed to estimate the respiratory virus infection burden, independent of symptom presentation, among older adults in Swedish LTCFs in the post-pandemic period (2021–2024).

Methods: We leveraged capillary blood samples and coupled national registry data from 1622 LTCF residents (median age = 87). A multiplex platform was used to quantify antigen-specific IgG and IgM responses to RSV (pre-/post-F, strain A-specific G-protein), influenza-A (H1N1 and H3N2 HA), influenza-B (HA) and SARS-CoV-2 (spike). Linear mixed-effects models were used to demonstrate the dynamics of antibody levels over time, adjusted for age, sex and comorbidities.

Results: RSV-specific antibody responses peaked in spring 2022 (p < 0.001), suggesting an impact of relaxed COVID-19-related restrictions on RSV exposure at LTCFs. RSV-specific antibodies subsequently declined over time until an increase during autumn 2023 (p < 0.001). Geographic variation in pre-F antibody levels suggested localised RSV outbreaks. The total estimated RSV burden at LTCFs was markedly higher than official reports of the Swedish Public Health Agency. Influenza antibody dynamics reflected seasonal trends and were strongly influenced by annual vaccination. A random forest classifier incorporating serological profiles with demographics, location and comorbidities significantly outperformed a model without serological data (AUC-ROC = 0.67 vs. 0.58), although discriminatory performance remained modest. Higher levels of RSV pre-F antibodies in autumn 2021 were associated with increased one-year mortality in logistic regression (OR = 1.43, p = 0.024). Exploratory survival analysis indicated a trend that elevated levels of RSV pre-F antibodies during low population immunity may confer a transiently elevated early hazard of death, although this did not reach statistical significance (HR = 4.50, p = 0.087).

Conclusions: We observed substantial respiratory virus circulation among older adults in Swedish LTCFs and show that RSV burden is under-reported. The results highlight a need for further research into the role of RSV pre-F antibody levels in preventing severe outcomes, potentially via vaccination of LTCF residents. Our scalable serological surveillance system is a valuable approach to detect respiratory infections in LTCFs, independent of symptom presentation or healthcare-seeking behaviour.

Methicillin-resistant Staphylococcus aureus resists β-lactam antibiotics through the allosteric transpeptidase penicillin-binding protein 2a, which operates within staphyloxanthin-rich membrane microdomains. Statins restore susceptibility by disrupting these microdomains and impairing penicillin-binding protein 2a oligomerization, but the mechanisms enabling resistance to this resensitization remain unclear. Here we show, using evolution experiments in strains lacking a functional staphyloxanthin pathway, that mutations in gdpP, a regulator of cyclic di-adenosine monophosphate signaling, are the predominant route for restoring oxacillin resistance during membrane microdomain disruption. This adaptation is blocked by simvastatin, revealing a synthetic lethal interaction. Mechanistically, simvastatin inhibits the mevalonate pathway, depleting the essential lipid carrier undecaprenyl phosphate and exacerbating peptidoglycan precursor imbalance, an effect phenocopied by lipid carrier–targeting antibiotics such as bacitracin. Although compensatory mutations can restore resistance, they impose a fitness cost in vivo. Importantly, this vulnerability extends to Streptococcus pneumoniae, revealing a conserved strategy to overcome β-lactam resistance in Gram-positive pathogens.

Background: The implementation of COVID-19 vaccination among older persons at nursing homes has lowered the infection-associated mortality considerably, but emerging virus variants and decline in vaccine-induced immunity over time necessitate examination of future booster dosing strategies. The overall aim of this study was to assess vaccine protection against COVID-19 mortality in relation to time elapsed since the last booster dose.

Methods: All older persons living in nursing homes in Sweden at any time point December 27th, 2020 - December 4th, 2023 were included. For each case (5256 COVID-19 and 85,745 all-cause deaths), up to 10 controls were sampled randomly from this population, matched with respect to birth year, sex and county. The matched case-control sets were analyzed for vaccination history with conditional logistic regression, with further adjustment for co-morbidties and prior SARS-CoV-2 infection.

Findings: Vaccination status (unvaccinated vs. vaccinated), ≥ 90 days since last vaccine dose, a co-morbidity score ≥ 2, and no previous SARS-CoV-2 infection were associated with death occurring within 30 days of a positive test. The odds ratio (OR) for COVID-19 death was 2.4 (95 % confidende interval [CI] 1.8–3.2) when contrasting at least 365 days with less than 90 days since the last vaccine dose.

Interpretation: Waning vaccine protection was observed already 90 days after the last vaccine dose among older people living in nursing homes. The reported ORs imply that more than one third of all COVID-19 deaths could in the investigated setting have been possible to prevent by more frequent vaccine boosting during 2022–2023.

Timely detection and surveillance of disease community spread is a potent tool for implementing effective public health interventions. This study investigates the National Telehealth Service (1177 helpline) across 18 regions in Sweden in 2020 to identify early signals of community transmission of COVID-19 at the beginning of the pandemic. Focusing on calls related to key COVID-19 symptoms (cough, fever, and breathing difficulties in adults), we analyze their frequency and distribution across referral categories, comparing them to 2019 data. We employ an explainable time series anomaly detection algorithm using daily call data to identify the first collective anomalies across regions. The results show that anomalies in call data were correlated with, but preceded, the first confirmed case infected in Sweden by a median of 7 days (IQR: 2.5–10.5) and the first hospitalized case infected in Sweden by a median of 13 days (IQR: 7.25–16). They also preceded the estimated onset of community spread, indicated by the absolute confirmed cases (median: 24.5, IQR: 18.25-32.5), and severe outcomes defined by hospitalizations (median: 33, IQR: 27.25-44). These findings showcase how helpline call monitoring, using time series anomaly detection, can aid early outbreak detection.

Background: The digitalization of information systems allows automatic measurement of antimicrobial consumption (AMC), helping address antibiotic resistance from inappropriate drug use without compromising patient safety.

Objectives: Describe and characterize a new automated AMC surveillance service for intensive care units (ICUs), with data stratified by referral clinic and linked with individual patient risk factors, disease severity, and mortality.

Methods: An automated service collecting data from the electronic medical record was developed, implemented, and validated in a healthcare region in northern Sweden. We performed an observational study from January 1, 2018, to December 31, 2021, encompassing general ICU care for all ≥18-years-olds in a catchment population of 270000 in secondary care and 900000 in tertiary care. We used descriptive analyses to associate ICU population characteristics with AMC outcomes over time, including days of therapy (DOT), length of therapy, defined daily doses, and mortality.

Results: There were 5608 admissions among 5190 patients with a median age of 65 (IQR 48-75) years, 41.2% females. The 30-day mortality was 18.3%. Total AMC was 1177 DOTs in secondary and 1261 DOTs per 1000 patient days and tertiary care. AMC varied significantly among referral clinics, with the highest total among 810 general surgery admissions in tertiary care at 1486 DOTs per 1000 patient days. Case-mix effects on the AMC were apparent during COVID-19 waves highlighting the need to account for case-mix. Patients exposed to more than three antimicrobial drug classes (N = 242) had a 30-day mortality rate of 40.6%, with significant variability in their expected rates based on admission scores.

Conclusion: We introduce a new service and instructions for automating local ICU-AMC data collection. The versatile long-term ICU-AMC metrics presented, covering patient factors, referral clinics and mortality outcomes, are expected to be beneficial in refining antimicrobial drug use.

Background: A multidrug-resistant lineage of Staphylococcus epidermidis named ST215 is a common cause of prosthetic joint infections and other deep surgical site infections in Northern Europe, but is not present elsewhere. The increasing resistance among S. epidermidis strains is a global concern. We used whole-genome sequencing to characterize ST215 from healthcare settings.

Results: We completed the genome of a ST215 isolate from a Swedish hospital using short and long reads, resulting in a circular 2,676,787 bp chromosome and a 2,326 bp plasmid. The new ST215 genome was placed in phylogenetic context using 1,361 finished public S. epidermidis reference genomes. We generated 10 additional short-read ST215 genomes and 11 short-read genomes of ST2, which is another common multidrug-resistant lineage at the same hospital. We studied recombination’s role in the evolution of ST2 and ST215, and found multiple recombination events averaging 30–50 kb. By comparing the results of antimicrobial susceptibility testing for 31 antimicrobial drugs with the genome content encoding antimicrobial resistance in the ST215 and ST2 isolates, we found highly similar resistance traits between the isolates, with 22 resistance genes being shared between all the ST215 and ST2 genomes. The ST215 genome contained 29 genes that were historically identified as virulence genes of S. epidermidis ST2. We established that in the nucleotide sequence stretches identified as recombination events, virulence genes were overrepresented in ST215, while antibiotic resistance genes were overrepresented in ST2.

Conclusions: This study features the extensive antibiotic resistance and virulence gene content in ST215 genomes. ST215 and ST2 lineages have similarly evolved, acquiring resistance and virulence through genomic recombination. The results highlight the threat of new multidrug-resistant S. epidermidis lineages emerging in healthcare settings.

Myocarditis is an inflammatory disease of the myocardium with either focal or diffuse involvement and usually gives rise to chest pain, dyspnea, palpitations, and fatigue. In severe cases, arrythmias, syncope, and cardiogenic shock may occur. Acute myocarditis is most commonly caused by a variety of viruses with cardiotropic properties. Rare causes of myocarditis include bacterial infections. We, herein, describe a case of acute myocarditis caused by the intracellular bacterium Francisella tularensis. A young and previously healthy male in Northern Sweden was referred to the emergency department due to intense upper-chest pain and dyspnea. ECG exhibited minimal ST-segment elevations and laboratory parameters revealed pathological levels of high-sensitivity cardiac troponin and C-reactive protein. Radiological imaging showed increased metabolism in enlarged lymph nodes in the chest and signs that could be compatible with increased metabolism in the left ventricular of the heart. The combination of acute myocarditis and enlarged lymph nodes was believed to be caused by the intracellular bacterium Francisella tularensis, endemic in the Northern Sweden, and was verified with positive serology. The patient showed full recovery after antimicrobial treatment. As this is the fifth published case of myocarditis associated with Francisella tularensis, we suggest considering tularemia in acute myocarditis in tularemia-endemic area.

Background: The current SARS-CoV-2 pandemic has highlighted a need for easy and safe blood sampling in combination with accurate serological methodology. Venipuncture for testing is usually performed by trained staff at healthcare centres. Long travel distances to healthcare centres in rural regions may introduce a bias of testing towards relatively large communities with closer access. Rural regions are therefore often not represented in population-based data.

Aim: The aim of this retrospective cohort study was to develop and implement a strategy for at-home testing in a rural region of Sweden during spring 2021, and to evaluate its role to provide equal health care for its inhabitants.

Methods: We developed a sensitive method to measure antibodies to the S-protein of SARS-CoV-2 and optimised this assay for clinical use together with a strategy of at-home capillary blood sampling.

Results: We demonstrated that our ELISA gave comparable results after analysis of capillary blood or serum from SARS-CoV-2-experienced individuals. We demonstrated stability of the assay under conditions that reflected temperature and humidity during winter or summer. By assessment of capillary blood samples from 4,122 individuals, we could show both feasibility of the strategy and that implementation shifted the geographical spread of testing in favour of rural areas.

Conclusion: Implementation of at-home sampling enabled citizens living in remote rural areas access to centralised and sensitive laboratory antibody tests. The strategy for testing used here could therefore enable disease control authorities to get rapid access to information concerning immunity to infectious diseases, even across vast geographical distance.

Importance: Quantifying the burden of nosocomial SARS-CoV-2 infections and associated mortality is necessary to assess the need for infection prevention and control measures.

Objective: To investigate the occurrence of nosocomial SARS-CoV-2 infections and associated 30-day mortality among patients admitted to hospitals in Region Stockholm, Sweden.

Design, Setting, and Participants: A retrospective, matched cohort study divided the period from March 1, 2020, until September 15, 2022, into a prevaccination period, early vaccination and pre-Omicron (period 1), and late vaccination and Omicron (period 2). From among 303 898 patients 18 years or older living in Region Stockholm, 538 951 hospital admissions across all hospitals were included. Hospitalized admissions with nosocomial SARS-CoV-2 infections were matched to as many as 5 hospitalized admissions without nosocomial SARS-CoV-2 by age, sex, length of stay, admission time, and hospital unit.

Exposure: Nosocomial SARS-CoV-2 infection defined as the first positive polymerase chain reaction test result at least 8 days after hospital admission or within 2 days after discharge.

Main Outcomes and Measures: Primary outcome of 30-day mortality was analyzed using time-to-event analyses with a Cox proportional hazards regression model adjusted for age, sex, educational level, and comorbidities.

Results: Among 2193 patients with SARS-CoV-2 infections or reinfections (1107 women [50.5%]; median age, 80 [IQR, 71-87] years), 2203 nosocomial SARS-CoV-2 infections were identified. The incidence rate of nosocomial SARS-CoV-2 infections was 1.57 (95% CI, 1.51-1.64) per 1000 patient-days. In the matched cohort, 1487 hospital admissions with nosocomial SARS-CoV-2 infections were matched to 5044 hospital admissions without nosocomial SARS-CoV-2 infections. Thirty-day mortality was higher in the prevaccination period (adjusted hazard ratio [AHR], 2.97 [95% CI, 2.50-3.53]) compared with period 1 (AHR, 2.08 [95% CI, 1.50-2.88]) or period 2 (AHR, 1.22 [95% CI, 0.92-1.60]). Among patients with nosocomial SARS-CoV-2 infections, 30-day AHR comparing those with 2 or more doses of SARS-CoV-2 vaccination and those with less than 2 doses was 0.64 (95% CI, 0.46-0.88).

Conclusions and Relevance: In this matched cohort study, nosocomial SARS-CoV-2 infections were associated with higher 30-day mortality during the early phases of the pandemic and lower mortality during the Omicron variant wave and after the introduction of vaccinations. Mitigation of excess mortality risk from nosocomial transmission should be a strong focus when population immunity is low through implementation of adequate infection prevention and control measures.