A serosurvey examining exposure to Borrelia burgdorferi sensu lato and tick-borne encephalitis virus in Danish blood donors, August 2022.

Objectives: Borrelia burgdorferi sensu lato (Bbsl) and tick-borne encephalitis virus (TBEV) are tick-borne pathogens. This study aimed to investigate the seroprevalence of these pathogens in Danish blood donors. Methods: A total of 1000 plasma samples equally distributed (n = 200) from all five Danish regions were analyzed. Commercially available enzyme-linked immunosorbent assays were used to screen the samples for immunoglobulin G antibodies against Bbsl and TBEV. The samples positive for antibodies against TBEV were further examined with a commercially available enzyme-linked immunosorbent assay and a Luminex-based TBEV suspension multiplex immunoassay for specific antibodies against non-structural protein 1 (NS1) antigen suggestive of previous infection. Results: A total of 62 samples tested positive for immunoglobulin G antibodies against Bbsl. A total of 40 samples were positive or borderline for antibodies against TBEV, indicating potential infection or vaccination. Of these, one had antibodies against NS1, indicating past infection. The seroprevalence of Bbsl was 6.2% (95% confidence interval 4.8-7.8), with equal seroprevalence in all five regions. The seroprevalence of TBEV was 0.1% (95% confidence interval 0.01-0.62%). Conclusions: The seroprevalence of Bbsl was similar throughout the country and corresponds well with previous studies. The seroprevalence of TBEV NS1 was low, which is in line with a low number of reported tick-borne encephalitis cases in Denmark. The NS1 positive sample was from the Capital Region, an endemic TBEV area.

Incidence of symptomatic Lyme borreliosis in nine European countries.

OBJECTIVES: To better understand the Lyme borreliosis (LB) burden in Europe, we aimed to estimate the incidence of symptomatic Borrelia burgdorferi sensu lato (Bbsl) infections after adjusting public health LB surveillance data for under-detection of symptomatic Bbsl infections. METHODS: Data from seroprevalence studies and estimates of the symptomatic proportion and duration of antibody detection in Bbsl-infected individuals, derived from reviews of the published literature, were used to adjust public health LB surveillance data to estimate the incidence of symptomatic Bbsl infection in nine European countries from 2018-2022. RESULTS: The prevalence of anti-Bbsl antibodies ranged from 2.3% in Romania to 9.4% in Germany. Under-detection multipliers varied across surveillance systems; using 10-year duration of antibody detection, multipliers were 2.4-10.5 in countries reporting all LB cases and 54.6-722.2 in countries reporting only Lyme neuroborreliosis cases. The incidence of symptomatic Bbsl infection adjusted for under-detection was highest in Finland, Germany, Norway, Poland, and Switzerland, intermediate in the Czech Republic and Denmark, and lowest in Ireland and Romania. CONCLUSIONS: Adjustment of LB surveillance for under-detection found a high incidence of symptomatic Bbsl infection in several European countries. Differences in LB surveillance systems should be considered when comparing surveillance data between countries and when estimating LB disease burden.

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, n = 637) or older children (≥90 days to <17 years, n = 1,218). We constructed a comparison cohort from the general population (n = 18,550), and cohorts of siblings of participants. As risk estimates of PNDD we calculated age- and sex-adjusted hazard ratios (aHRs) with 95% confidence intervals (95%CI). RESULTS: Children with bacterial meningitis had increased risks of PNDD, especially learning and intellectual developmental disorders (young infants: aHR 4.2, 95%CI: 2.4-7.1; older children: aHR 1.5, 95%CI: 1.0-2.3), attention deficit disorder (ADHD) (young infants: aHR 2.8, 95%CI: 1.5-5.2; older children: 1.4, 95%CI: 0.9-2.2) and redemption of ADHD medication (young infants: aHR 2.2, 95%CI: 1.0-4.7; older children: 1.5, 95%CI: 1.0-2.3). Young infants with bacterial meningitis additionally had increased risks of autism spectrum disorders (aHR 1.9, 95%CI: 0.9-4.1) and behavioural and emotional disorders (aHR 2.0, 95%CI: 1.0-3.9). In young infants, the excess risk of PNDD was especially observed in premature children. Siblings of older children with bacterial meningitis also had increased risks of PNDD. Children with enteroviral meningitis at any age did not have increased risks of PNDD or redemption of ADHD medication. CONCLUSIONS: Bacterial meningitis in childhood is associated with subsequent diagnosis of PNDD, while enteroviral meningitis is not. The association appears to be partly explained by prematurity and familial and socioeconomic factors.

Maximal respiratory pressure after COVID-19 compared with reference material in healthy adults: A prospective cohort study (The SECURe study).

After COVID-19 long term respiratory symptoms and reduced lung function including maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) have been reported. However, no studies have looked at MIP and MEP in all disease groups and the reference materials collection methods differ substantially. We aimed to determine MIP and MEP in individuals after COVID-19 infection with different disease severity using reference material of healthy control group obtained using the same standardized method. Patients with COVID-19 were included March 2020-March 2021 at Rigshospitalet, Denmark. MIP and MEP were measured using microRPM. Predicted MIP and MEP were calculated using reference material obtained from 298 healthy adults aged 18-97 years using the same method. In SECURe, 145 participants were measured median 5 months after COVID-19 diagnosis and of these 16% had reduced MIP and/or MEP. There was reduced spirometry and total lung capacity, but not reduced diffusion capacity in those with abnormal MIP and/or MEP compared with normal MIP and MEP. Of those with reduced MIP and/or MEP at 5 months, 80% still had reduced MIP and/or MEP at 12 months follow-up. In conclusion, few have reduced MIP and/or MEP 5 months after COVID-19 and little improvement was seen over time.

Peripheral facial palsy in children: Serum Borrelia antibodies may reduce the need for lumbar puncture.

AIM: We aimed to investigate the causes of acute peripheral facial palsy (PFP) in Danish children and to explore whether neuroborreliosis-related PFP could be diagnosed without lumbar puncture using clinical symptoms and serum Borrelia burgdorferi (Bb) antibodies. METHODS: This retrospective population-based cohort study included children undergoing lumbar puncture for PFP between 2019 and 2023 in Denmark's Capital Region. Diagnostic performance measures for neuroborreliosis-related PFP were compared between serum Bb IgG alone and clinical risk scores combining Bb IgG with clinical parameters. RESULTS: Of the 326 patients with PFP, 137 (42%) were diagnosed with neuroborreliosis and 151 (46%) had Bell's palsy. Positive predictive value for serum Bb IgG alone was 88% (95% CI 79-93) and negative predictive value was 83% (95% CI 75-88). The positive predictive value of a risk score with seven additional parameters was 90% (95% CI 81-95) and negative predictive value 87% (95% CI 80-92). CONCLUSION: The positive predictive value of serum Bb IgG alone was high in our setting, where nearly half of children with PFP had neuroborreliosis. In high endemic settings, lumbar punctures may be reduced by (i) treating all children with PFP with doxycycline or (ii) treating Bb IgG positive children and performing lumbar puncture in seronegative children.

Deep immune cell phenotyping and induced immune cell responses at admission stratified by BMI in patients hospitalized with COVID-19: An observational multicenter cohort pilot study.

INTRODUCTION: Overweight and obesity are linked to increased hospitalization and mortality in COVID-19 patients. This study aimed to characterize induced immune responses and deep immune cell profiles stratified by BMI in hospitalized COVID-19 patients. METHODS AND RESULTS: This observational multicenter cohort pilot study included 122 adult patients with PCR-confirmed COVID-19 in Denmark, stratified by BMI (normal weight, overweight, obese). Inflammation was assessed using TruCulture® and immune cell profiles by flow cytometry with a customized antibody panel (DuraClone®). Patients with obesity had a more pro-inflammatory phenotype with increased TNF-α, IL-8, IL-17, and IL-10 levels post-T cell stimulation, and altered B cell profiles. Patients with obesity showed higher concentrations of naïve, transitional, and non-isotype switched memory B cells, and plasmablasts compared to normal weight patients and healthy controls. CONCLUSIONS: Obesity in hospitalized COVID-19 patients may correlate with elevated pro-inflammatory cytokines, anti-inflammatory IL-10, and increased B cell subset activation, highlighting the need for further studies.

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). We randomly selected controls from the general population and matched 10:1 on date of birth and sex. Exposures were assignment of diagnostic codes for symptoms, contact to medical specialties, medical wandering, and undergoing diagnostic procedures. We calculated the weekly and 3-month proportions of individuals with exposures and calculated absolute risk differences with corresponding 95% CI. RESULTS: We included 1056 cases with LNB and 10 560 controls. Within 3 months before diagnosis, the most frequent assigned symptoms were pain (difference: 13.0%, 95% CI: 10.9-15.1). Cases with LNB exhibited increased contact with most specialties, particularly general practitioners (difference: 48.7%, 95% CI: 46.0-51.4), neurology (difference: 14.3%, 95% CI: 11.7-16.8), and internal medicine (difference: 11.1%, 95% CI: 8.7-13.5), and medical wandering (difference: 17.1%, 95% CI: 14.3-20.0). Common diagnostic procedures included imaging of the brain (difference: 10.2, 95% CI: 8.3-12.1), the spine (difference: 8.8%, 85% CI: 7.0-10.6), and the abdomen (difference: 7.2%, 95% CI: 5.4-9.1). The increase in healthcare-seeking behaviour was observed ≤12 weeks preceding diagnosis. DISCUSSION: Pain appears to be an ambiguous symptom of LNB, potentially contributing to delays in establishing the correct diagnosis. It would be difficult to identify patients with LNB more effectively as the increased healthcare-seeking behaviour preceding diagnosis is distributed across many medical specialties.

Repeated doxycycline treatment among patients with neuroborreliosis: a nationwide, population-based, registry-based, matched cohort study.

OBJECTIVES: To investigate receipt of antibiotics among patients with neuroborreliosis after initial antibiotic treatment, likely attributable to posttreatment symptoms. METHODS: We performed a nationwide, matched, population-based cohort study in Denmark (2009-2021). We included all Danish patients with neuroborreliosis, i.e. a positive Borrelia burgdorferi intrathecal antibody index test and a cerebrospinal fluid leukocyte count ≥10 × 106/l, and initially treated with doxycycline. To form a comparison cohort, we randomly extracted individuals from the general population matched 1:10 to patients with neuroborreliosis on date of birth and sex. The main outcome was receipt of doxycycline, and the secondary outcome was receipt of phenoxymethylpenicillin. We calculated short-term (<1 year) and long-term (≥1 year) hazard ratios (HR) with 95% confidence intervals (95%CI). RESULTS: We included 463 patients with neuroborreliosis and 2,315 comparison cohort members. Compared with the comparison cohort members, patients with neuroborreliosis initially treated with doxycycline had increased receipt of additional doxycycline within 1 year (HR: 38.6, 95%CI: 17.5-85.0) and ≥1 years (HR: 3.5, 95%CI: 1.9-6.3). Compared with comparison cohort members, patients with neuroborreliosis had no increased receipt of phenoxymethylpenicillin (<1 year HR 1.0, 95%CI: 0.7-1.3; ≥1 years HR 1.2, 95%CI: 0.9-1.5). CONCLUSIONS: After initial antibiotic treatment, patients with neuroborreliosis have increased receipt of doxycycline particularly within one year after initial antibiotic therapy but also subsequently. The lack of increased receipt of phenoxymethylpenicillin suggests that the receipt of doxycycline was not merely due to differences in healthcare-seeking behaviour, increased risk of early Lyme borreliosis due to exposure, or differences in antibacterial usage in general.

Use of intensive care, intracranial pressure monitoring, and external ventricular drainage devises in patients with bacterial meningitis, a cohort study.

BACKGROUND: Bacterial meningitis can cause a life-threatening increase in intracranial pressure (ICP). ICP-targeted treatment including an ICP monitoring device and external ventricular drainage (EVD) may improve outcomes but is also associated with the risk of complications. The frequency of use and complications related to ICP monitoring devices and EVDs among patients with bacterial meningitis remain unknown. We aimed to investigate the use of ICP monitoring devices and EVDs in patients with bacterial meningitis including frequency of increased ICP, drainage of cerebrospinal fluid (CSF), and complications associated with the insertion of ICP monitoring and external ventricular drain (EVD) in patients with bacterial meningitis. METHOD: In a single-center prospective cohort study (2017-2021), we examined the frequency of use and complications of ICP-monitoring devices and EVDs in adult patients with bacterial meningitis. RESULTS: We identified 108 patients with bacterial meningitis admitted during the study period. Of these, 60 were admitted to the intensive care unit (ICU), and 47 received an intracranial device (only ICP monitoring device N = 16; EVD N = 31). An ICP > 20 mmHg was observed in 8 patients at insertion, and in 21 patients (44%) at any time in the ICU. Cerebrospinal fluid (CSF) was drained in 24 cases (51%). Severe complications (intracranial hemorrhage) related to the device occurred in two patients, but one had a relative contraindication to receiving a device. CONCLUSIONS: Approximately half of the patients with bacterial meningitis needed intensive care and 47 had an intracranial device inserted. While some had conservatively correctable ICP, the majority needed CSF drainage. However, two patients experienced serious adverse events related to the device, potentially contributing to death. Our study highlights that the incremental value of ICP measurement and EVD in managing of bacterial meningitis requires further research.

Cervical cancer screening integrated in routine clinical care of women with HIV.

OBJECTIVE: To evaluate if integrated cervical cancer screening (CCS) for women with HIV (WWH) in routine HIV care resulted in increased adherence to screening, and to describe the prevalence of human papillomavirus (HPV)-specific genotypes and the incidence of cellular abnormalities. DESIGN: Cohort study. METHODS: WWH who accepted the offer of combined CCS and HIV care (group 1), WWH who declined the offer (group 2), and WWH not offered CCS within HIV care (group 3) between 2013 and 2019 were included. Data was collected from The Danish HIV Cohort Study and The Danish Pathology Data Bank. Adherence to the CCS program was defined as fulfilled if WWH were screened annually. RESULTS: A total of 804 WWH were included. WWH who accepted CCS within HIV care (group 1; n  = 218) had significantly higher adherence to screening in all study years 22-99% compared with the WWH who declined CCS (group 2; n  = 232) 10-16% and WWH who were not invited for CCS (group 3; n  = 354) 11-25%. There was no significant difference in the prevalence of HPV-specific genotypes and incidence of cellular abnormalities among the three groups. CONCLUSION: Integrating CCS for WWH in routine HIV care resulted in higher adherence to the CCS guidelines. Combined services thereby represent an opportunity to engage WWH in HIV care into preventive services.

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). all Danish residents with LNB (positive Borrelia burgdorferi intrathecal antibody index test and cerebrospinal fluid pleocytosis) were included. To form a comparison cohort, individuals from the general population were randomly extracted and matched 10:1 to patients with LNB on age and sex. Outcomes were obtainment of simple analgesics, antiepileptics, tricyclic antidepressants, serotonin and noradrenaline reuptake inhibitors, tramadol, and other opioids. We calculated monthly and six-monthly proportions of individuals with obtainment of analgesics and absolute risk differences. RESULTS: 1,056 patients with LNB and 10,560 comparison cohort members were included. An increased proportion of patients with LNB obtained analgesics from 3 months before study inclusion, especially simple analgesics, tramadol, and other opioids. Within the 0-1-month period after study inclusion, patients with LNB most frequently obtained simple analgesics (15 %), antiepileptics (11 %), and tramadol (10 %). Thereafter, obtainment of analgesics declined within a few months. A slightly larger proportion of patients with LNB obtained antiepileptics up to 2.5 years after diagnosis. CONCLUSIONS: Up to 3 months preceding diagnosis, LNB was preceded by increased obtainment of analgesics, which suggests diagnostic delay. Importantly, most patients with LNB did not obtain analgesics after the immediate disease course, although obtainment remained more frequent up to 2.5 years after.

Validation of a risk score to differentiate autoimmune and viral encephalitis: a Nationwide Cohort Study in Denmark.

BACKGROUND: A score to differentiate autoimmune (AE) and viral encephalitis (VE) early upon admission has recently been developed but needed external validation. The objective of this study was to evaluate the performance of the score in a larger and more diagnostically diverse patient cohort. METHODS: We conducted a retrospective nationwide and population-based cohort study including all adults with encephalitis of definite viral (2015-2022) or autoimmune aetiology (2009-2022) in Denmark. Variables included in the score-model were extracted from patient records and individual risk scores were assessed. The performance of the score was assessed by receiver-operating characteristics (ROC) curve analyses and calculation of the area under the curve (AUC). RESULTS: A total of 496 patients with encephalitis [AE n = 90, VE n = 287 and presumed infectious encephalitis (PIE) n = 119] were included in the study. The score was highly accurate in predicting cases of AE reaching an AUC of 0.94 (95% CI 0.92-0.97). Having a score ≥ 3 predicted AE with a PPV of 87% and an NPV of 91%. The risk score was found to perform well across aetiological subgroups and applied to the PIE cohort resulted in an AUC of 0.88 (95% CI 0.84-0.93). CONCLUSION: The excellent performance of the score as reported in the development study was confirmed in this significantly larger and more diverse cohort of patients with encephalitis in Denmark. These results should prompt further prospective testing with wider inclusion criteria.

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. METHODS: We performed a matched nationwide cohort study (Denmark, 1993-2020) and included 52,200 Bb seropositive individuals, and two age- and sex-matched comparison cohorts: 1) 104,400 Bb seronegative comparison cohort members, and 2) 261,000 population controls. We investigated the risk associated with 1) being tested for serum Bb antibodies, and 2) being Bb seropositive. Outcomes were: 1) a composite of heart failure, cardiomyopathy, and/or myocarditis diagnosis, and 2) redemption of cardiovascular medicine used for treatment of heart failure. We calculated short-term odds ratios (aOR) (within 1 month) and long-term hazard rates (aHR) (after 1 month) adjusted for age, sex, diabetes, pre-existing heart failure, and kidney disease. RESULTS: Compared with the population controls, individuals tested for Bb antibodies, regardless of the test result, had increased short-term risk of heart failure, cardiomyopathy, and myocarditis (aOR 8.3, 95 %CI: 6.7-10.2), and both increased short- and long-term risk of redemption of cardiovascular medicine (aOR 4.3, 95 %CI: 3.8-4.8, aHR 1.13, 95 % CI: 1.11-1.15). The Bb seropositive individuals had no increased short- or long-term risk of any outcome compared with Bb seronegative comparison cohort members. CONCLUSIONS: In conclusion, Bb antibody tests seemed to be performed in the diagnostic work-up of heart failure, but Bb seropositivity was not associated with heart failure.

Neoehrlichiosis associated with ocrelizumab in a patient with multiple sclerosis: A case report.

OBJECTIVE: To describe a case of neoehrlichiosis, an emerging opportunistic tick-borne infection, in a patient with multiple sclerosis (MS) treated with ocrelizumab. METHODS: This is a case study. RESULTS: Our patient developed clinical infection over several months while on ocrelizumab and was ultimately diagnosed with neoehrlichiosis, caused by the bacteria Neoehrlichia mikurensis. Resolution of symptoms began within a few days after the initiation of antibiotic treatment. CONCLUSION: We describe the first probable case of ocrelizumab-associated neoehrlichiosis in a patient with MS. Clinicians should be aware of this potentially debilitating and life-threatening infection in patients receiving CD20-depleting therapy.

Pulmonary diffusing capacity for carbon monoxide and nitric oxide after COVID-19: A prospective cohort study (the SECURe study).

Many patients exhibit persistently reduced pulmonary diffusing capacity after coronavirus disease 2019 (COVID-19). In this study, dual test gas diffusing capacity for carbon monoxide and nitric oxide (DL,CO,NO) metrics and their relationship to disease severity and physical performance were examined in patients who previously had COVID-19. An initial cohort of 148 patients diagnosed with COVID-19 of all severities between March 2020 and March 2021 had a DL,CO,NO measurement performed using the single-breath method at 5.7 months follow-up. All patients with at least one abnormal DL,CO,NO metric (n = 87) were revaluated at 12.5 months follow-up. The DL,CO,NO was used to provide the pulmonary diffusing capacity for nitric oxide (DL,NO), the pulmonary diffusing capacity for carbon monoxide (DL,CO,5s), the alveolar-capillary membrane diffusing capacity and the pulmonary capillary blood volume. At both 5.7 and 12.5 months, physical performance was assessed using a 30 s sit-to-stand test and the 6 min walk test. Approximately 60% of patients exhibited a severity-dependent decline in at least one DL,CO,NO metric at 5.7 months follow-up. At 12.5 months, both DL,NO and DL,CO,5s had returned towards normal but still remained abnormal in two-thirds of the patients. Concurrently, improvements in physical performance were observed, but with no apparent relationship to any DL,CO,NO metric. The severity-dependent decline in DL,NO and DL,CO observed at 5.7 months after COVID-19 appears to be reduced consistently at 12.5 months follow-up in the majority of patients, despite marked improvements in physical performance.

Questioning risk compensation: pre-exposure prophylaxis (PrEP) and sexually transmitted infections among men who have sex with men, capital region of Denmark, 2019 to 2022.

BackgroundPre-exposure prophylaxis (PrEP) effectively prevents HIV, but its association with sexually transmitted infections (STIs) has raised concerns about risk compensation, potentially impacting the expansion of PrEP programmes.AimWe examined the relationship between PrEP and the incidence of chlamydia, gonorrhoea and syphilis.MethodsIn this prospective cohort study, we compared STI rates before and after PrEP initiation among users in the capital region of Denmark (2019-2022), calculating incidence rate ratios adjusted for age and testing frequency (aIRR). To pinpoint when increases began, we plotted weekly STI rates, adjusting the timeline to correspond with PrEP initiation.ResultsThe study included 1,326 PrEP users with a median age of 35 years. The STI incidence rate per 100,000 person-years rose from 35.3 before to 81.2 after PrEP start, with an aIRR of 1.35 (95% CI: 1.18-1.56). Notably, this increase preceded PrEP initiation by 10-20 weeks. Specific aIRR for chlamydia, gonorrhoea and syphilis were 1.23 (95% CI: 1.03-1.48), 1.24 (95% CI: 1.04-1.47) and 1.15 (95% CI: 0.76-1.72), respectively. In subanalyses for anatomical sites aIRR was 1.26 (95% CI: 1.01-1.56) for rectal chlamydia and 0.66 (95% CI: 0.45-0.96) for genital gonorrhoea.ConclusionWe found a 35% increase in STI incidence associated with PrEP use. It started before PrEP initiation, challenging the assumption that PrEP leads to risk compensation. Instead, the data suggest that individuals seek PrEP during periods of heightened sexual risk-taking. Consequently, PrEP programmes should include sexual health consultations, STI testing, treatment and prevention strategies to prevent HIV and improve sexual health.

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. We investigated the risk associated with being tested for serum Bb antibodies and being Bb seropositive. Outcomes were atrioventricular block and other conduction disorders. We calculated short-term odds ratios (aOR) (within 1 month), and long-term hazard ratios (aHR) (after 1 month) adjusted for age, sex, diabetes, chronic heart failure, and kidney disease with 95% CI. RESULTS: Compared with population controls, individuals tested for Bb antibodies had increased short- and long-term risks of atrioventricular block (aOR 47.9, 95% CI: 30.0-76.7, aHR 1.3, 95% CI:1.2-1.3), and other conduction disorders (aOR 18.2, 95% CI: 10.1-32.8, aHR 1.2, 95% CI: 1.1-1.4). Compared with Bb-seronegative individuals, only Bb-IgM-and-IgG-seropositive individuals had increased short-term risk of atrioventricular block (aOR: 2.1, 95% CI: 1.5-3.1). DISCUSSION: The results suggest that Bb antibody testing is included in the diagnostic work-up of conduction disorders. Finally, that Bb seropositivity is not associated with other conduction disorders than atrioventricular block or with increased long-term risk of conduction disorders.

Neoehrlichia mikurensis is uncommon in rheumatological patients receiving tumour necrosis factor inhibitors and in blood donors: a retrospective cohort study.

INTRODUCTION: Neoehrlichia mikurensis is a tick-borne bacterium that primarily causes disease in immunocompromised patients. The bacterium has been detected in ticks throughout Europe, with a 0%-25% prevalence. N. mikurensis infection presents unspecific symptoms, which can easily be mistaken for inflammatory disease activity. We aimed to determine the prevalence of N. mikurensis in rheumatological patients receiving tumour necrosis factor inhibitors (TNFi) and a cohort of healthy individuals. MATERIALS AND METHODS: This retrospective cohort study included 400 rheumatological patients treated with TNFi and 400 healthy blood donors. Plasma samples were retrieved from the Danish Rheumatological Biobank and the Danish Blood Donor Study between 2015 and 2022. Age, sex, diagnosis and duration of TNFi treatment were recovered from the Danish Rheumatological Database, DANBIO. Data on age and sex were available for the blood donors. One plasma sample per individual was tested for N. mikurensis DNA-specific real-time PCR targeting the groEL gene. RESULTS: In the rheumatological patients, the median age was 61 years (IQR 55-68 years), 62% were women, and 44% had a diagnosis of seropositive rheumatoid arthritis. In total, 54% of the patients were treated with infliximab. The median time from TNFi initiation to blood sampling was 20 months (IQR, 5-60 months). N. mikurensis DNA was not detected in any samples from patients or blood donors. CONCLUSION: N. mikurensis infection does not appear to represent a prevalent risk in Danish rheumatological patients receiving TNFi or in blood donors.

Prospective screening for monkeypox infection among users of HIV pre-exposure prophylaxis in Denmark.

INTRODUCTION: During the 2022 outbreak of mpox (previously called monkeypox), which primarily affected Gay, Bisexual, and other Men who have Sex with Men (GBMSM), testing was mainly limited to individuals with symptoms of infection. Although sporadic cases of mpox continue to be diagnosed in Denmark, the feasibility of screening asymptomatic high-risk populations, such as those using HIV pre-exposure prophylaxis (PrEP), is still unknown. METHODS: During the autumn of 2022, a rectal swab test for mpox PCR was included in the routine sexually transmitted infections (STI) screening for PrEP users. RESULTS: The screening included 224 asymptomatic men with a median age of 36.5 years. One patient (0.4%) tested positive for mpox. Ten (4.5%) and nine (4.0%) had chlamydia and gonorrhea, respectively. DISCUSSION: Our study demonstrates that screening for mpox is feasible in two Danish PrEP clinics.