Neoehrlichia mikurensis in Danish immunocompromised patients: a retrospective cohort study.

BACKGROUND: The tick-borne bacterium, Neoehrlichia mikurensis (N. mikurensis) can cause severe febrile illness and thromboembolic complications in immunocompromised individuals. We investigated the presence of N. mikurensis DNA in retrospectively collected plasma from a well-characterized cohort of Danish immunocompromised patients. METHODS: Plasma samples from 239 patients with immune dysfunction related to hematological or rheumatological disease or due to immunosuppressive therapy, were retrieved from a transdisciplinary biobank (PERSIMUNE) at Rigshospitalet, Copenhagen, Denmark. Serving as immunocompetent controls, plasma samples from 192 blood donors were included. All samples were collected between 2015 and 2019. Real-time PCR targeting the groEL gene was used to detect N. mikurensis DNA. Sequencing was used for confirmation. Borrelia burgdorferi sensu lato IgG antibodies were detected by ELISA as a proxy of tick exposure. Prevalence was compared using Fisher's exact test. RESULTS: Neoehrlichia mikurensis DNA was detected in 3/239 (1.3%, 95% confidence interval (CI): 0.3 - 3.6%) patients, all of whom primarily had a hematological disease. Follow-up samples of these patients were negative. N. mikurensis DNA was not detected in any of the blood donor samples. IgG antibodies against B. burgdorferi s.l. were detected with similar prevalence in immunocompromised patients and blood donors, i.e., 18/239 (7.5%, 95% CI: 4.8-11.5%) and 11/192 (5.7%, 95%: CI 3.2-10.0%). CONCLUSION: In this study, patients with N. mikurensis were not identified by clinical indication and N. mikurensis may therefore be underdiagnosed in Danish patients. Further investigations are needed to explore the clinical significance and implications of this infection.

Tick-transmitted co-infections among erythema migrans patients in a general practice setting in Norway: a clinical and laboratory follow-up study.

BACKGROUND: Erythema migrans (EM) is the most common manifestation of Lyme borreliosis. Here, we examined EM patients in Norwegian general practice to find the proportion exposed to tick-transmitted microorganisms other than Borrelia, and the impact of co-infection on the clinical manifestations and disease duration. METHODS: Skin biopsies from 139/188 EM patients were analyzed using PCR for Neoehrlichia mikurensis, Rickettsia spp., Anaplasma phagocytophilum and Babesia spp. Follow-up sera from 135/188 patients were analyzed for spotted fever group (SFG) Rickettsia, A. phagocytophilum and Babesia microti antibodies, and tested with PCR if positive. Day 0 sera from patients with fever (8/188) or EM duration of ≥ 21 days (69/188) were analyzed, using PCR, for A. phagocytophilum, Rickettsia spp., Babesia spp. and N. mikurensis. Day 14 sera were tested for TBEV IgG. RESULTS: We detected no microorganisms in the skin biopsies nor in the sera of patients with fever or prolonged EM duration. Serological signs of exposure against SFG Rickettsia and A. phagocytophilum were detected in 11/135 and 8/135, respectively. Three patients exhibited both SFG Rickettsia and A. phagocytophilum antibodies, albeit negative PCR. No antibodies were detected against B. microti. 2/187 had TBEV antibodies without prior immunization. There was no significant increase in clinical symptoms or disease duration in patients with possible co-infection. CONCLUSIONS: Co-infection with N. mikurensis, A. phagocytophilum, SFG Rickettsia, Babesia spp. and TBEV is uncommon in Norwegian EM patients. Despite detecting antibodies against SFG Rickettsia and A. phagocytophilum in some patients, no clinical implications could be demonstrated.

Transnational exchange of surveillance data reveals previously unrecognized TBEV microfocus.

Tick-borne encephalitis (TBE) is a tick-borne infection with an increasing presence in many European countries. It is caused by the TBE virus (TBEV), a flavivirus transmitted by the Ixodes ricinus tick in northern Europe. In Denmark, the virus exists endemically on the island of Bornholm. However, a large proportion of Danish cases are also imported from Sweden, where the incidence of TBE has steadily been increasing during the last few decades. With the prospect of expanding risk areas due to climate change, TBE surveillance data exchange between countries could facilitate the identification of new TBEV microfoci and thereby aid healthcare workers in the issuing of vaccination recommendations. We present data from a collaborative effort between Denmark and Sweden on the surveillance of TBEV that resulted in the uncovering of a previously unrecognized possible TBEV microfocus in central Sweden.

Evidence of rickettsiae in Danish patients tested for Lyme neuroborreliosis: a retrospective study of archival samples.

BACKGROUND: With a prevalence of 4.7-13% in Danish Ixodes ricinus ticks, Rickettsia helvetica is one of the most frequently detected tick-borne organisms in Denmark. Most reports of human exposure have described asymptomatic seroconversion or a mild, self-limiting flu-like illness but it has also been implicated as a cause of subacute lymphocytic meningitis. Because Borrelia burgdorferi sensu lato (Bbsl) and R. helvetica are both found in the same tick species, potential co-transmission is a possibility. We examined 1) the seroprevalence of anti-rickettsia antibodies in patients investigated for Lyme neuroborreliosis (LNB), and 2) the cerebrospinal fluid (CSF) and sera of same patients for the presence of Rickettsia DNA. METHODS: Ninety-nine sera and 87 CSF samples from patients with intrathecal synthesis of anti-Borrelia antibodies and 101 sera and 103 CSF samples from patients with no detectable intrathecal synthesis were retrospectively examined for this study. Sera were analyzed for antibodies against spotted fever group (SFG) rickettsiae and both the CSF and sera were tested for Rickettsia DNA using a genus-specific real-time PCR. RESULTS: Of the patients tested for LNB, 32% (64/200) had IgG antibodies against SFG rickettsiae. Among patients with confirmed intrathecal synthesis of Borrelia-specific antibodies, 38% (38/99) exhibited IgG antibodies. None of these values were statistically significant when compared with sera from healthy blood donors (p = 0.7 and 0.19). Rickettsia DNA was found in the CSF of 4% (8/190) of patients. CONCLUSION: No statistically significant difference was found in the seroprevalence of anti-rickettsia antibodies in patients tested for LNB and healthy blood donors, indicative of a low rate of exposure in this group of patients. Eight patients showed evidence of Rickettsia DNA in the CSF, five of whom had LNB. However, cycle threshold (Ct) values were high, indicating low concentrations of DNA, and no apparent alteration in the clinical manifestations of LNB were noted in the medical records of these patients.

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. METHODS: Serological data from the departments of clinical microbiology at Karlstad Hospital, Sweden, and Slagelse Hospital, Denmark, were used to calculate a seroreactivity cut-off (SCOFF), above which changes between two samples from the patient cannot be explained by random variation. Increases in IgG reactivity as well as IgG and IgM decay were illustrated using time-to-event analysis and the SCOFF. RESULTS: A total of 44,861 serum samples from 34,157 patients were tested for Bbsl-antibodies. Of the 4301 patients with follow-up samples taken within 100 days, 201 (4.67%) were above the SCOFF of 1.42 with a median time to follow-up sample of 36 days (interquartile range: 21). IgG demonstrated longer median time for all antibody levels (indeterminate: 4.6 years, low: 7.0 years, moderate-high: 8.8 years) than IgM antibodies (indeterminate: 2.1 years, low: 3.9 years, moderate-high: 6.8 years) and higher initial antibody levels persisted significantly longer for both IgG and IgM antibodies (p < 0.001). Of the 7868 patients with follow-up samples, isolated IgM reactivity preceded an increase in IgG reactivity in 18 patients (0.23%). DISCUSSION: The SCOFF indicated little biological and random variation for Bbsl-specific IgG antibodies on the platforms used during the study. In most follow-up samples, both IgG and IgM antibodies persisted for years, with longer seropositivity associated with high initial antibody levels and IgG-type antibodies. The diagnostic value of isolated IgM reactivity was limited.

Genomic profiling of a randomized trial of interferon-α vs hydroxyurea in MPN reveals mutation-specific responses.

Although somatic mutations influence the pathogenesis, phenotype, and outcome of myeloproliferative neoplasms (MPNs), little is known about their impact on molecular response to cytoreductive treatment. We performed targeted next-generation sequencing (NGS) on 202 pretreatment samples obtained from patients with MPN enrolled in the DALIAH trial (A Study of Low Dose Interferon Alpha Versus Hydroxyurea in Treatment of Chronic Myeloid Neoplasms; #NCT01387763), a randomized controlled phase 3 clinical trial, and 135 samples obtained after 24 months of therapy with recombinant interferon-alpha (IFNα) or hydroxyurea. The primary aim was to evaluate the association between complete clinicohematologic response (CHR) at 24 months and molecular response through sequential assessment of 120 genes using NGS. Among JAK2-mutated patients treated with IFNα, those with CHR had a greater reduction in the JAK2 variant allele frequency (median, 0.29 to 0.07; P < .0001) compared with those not achieving CHR (median, 0.27 to 0.14; P < .0001). In contrast, the CALR variant allele frequency did not significantly decline in those achieving CHR or in those not achieving CHR. Treatment-emergent mutations in DNMT3A were observed more commonly in patients treated with IFNα compared with hydroxyurea (P = .04). Furthermore, treatment-emergent DNMT3A mutations were significantly enriched in IFNα-treated patients not attaining CHR (P = .02). A mutation in TET2, DNMT3A, or ASXL1 was significantly associated with prior stroke (age-adjusted odds ratio, 5.29; 95% confidence interval, 1.59-17.54; P = .007), as was a mutation in TET2 alone (age-adjusted odds ratio, 3.03; 95% confidence interval, 1.03-9.01; P = .044). At 24 months, we found mutation-specific response patterns to IFNα: (1) JAK2- and CALR-mutated MPN exhibited distinct molecular responses; and (2) DNMT3A-mutated clones/subclones emerged on treatment.

Higher rate of SARS-CoV-2 IgG seropositivity in hospital-based healthcare workers compared to elderly care staff in a Swedish low-prevalence region: a cross-sectional study.

BACKGROUND: Previous seroprevalence studies have demonstrated higher anti-SARS-CoV-2 IgG seroprevalence in healthcare workers (HCWs) than in the background population during the first phase of the 2020 COVID-19 pandemic. These studies, however, focussed mainly on hospital employees. AIM: To perform a cross-sectional study comparing the seroprevalence of hospital-based HCWs with those employed in elderly care (home care and nursing homes). METHODS: Employees (n = 4955) in the county of Värmland, Sweden, were recruited between weeks 27 and 42 and tested for IgG antibodies against SARS-CoV-2. Serological results were combined with self-reported questionnaire data. FINDINGS: IgG seroprevalence was 5.7% in the total group of HCWs, and was higher among those employed in hospital-based healthcare than among those working in elderly care (8.4% vs. 3.7%, p < .001). Being employed as an assistant nurse, working in a COVID-19 unit, and being exposed via co-workers or private acquaintances were all associated with IgG seropositivity. CONCLUSION: The difference in seroprevalence between HCWs in the two settings suggests that not only the profession but also factors in the workplace environment may be of importance. As all studied exposures were associated with IgG seropositivity, and asymptomatic infection was detected in 7.5% of participants, preventing outbreaks among HCWs is challenging. Adequate use of personal protective equipment when working with patients regardless of COVID-19 status, source control in situations with co-workers in which distancing is not possible, and routines enabling symptomatic staff to isolate pending PCR results are required to prevent healthcare-associated outbreaks of COVID-19.

Emerging tick-borne pathogens in the Nordic countries: A clinical and laboratory follow-up study of high-risk tick-bitten individuals.

Despite the presence of several microorganisms, other than Borrelia burgdorferi sensu lato (Bbsl) and TBE virus, in Ixodes ricinus ticks from the Nordic countries, data is lacking on their pathogenic potential in humans. In this study, we wanted to investigate the aetiology and clinical manifestations of tick-transmitted infections in individuals seeking medical care following a tick-bite. The sampling frame was participants of a large-scale, prospective, multi-centre, follow-up study of tick-bitten volunteers recruited in Sweden, Finland and Norway in the years 2007-2015. Participants who sought medical care during the three-month follow-up period and from whom blood samples were collected during this healthcare visit (n = 92) were tested, using PCR, for exposure to spotted fever group (SFG) Rickettsia spp., Anaplasma phagocytophilum and Babesia spp. Moreover, 86 of these individuals had two serum samples, collected three months apart, tested serologically for six tick-borne microorganisms. The selected organisms - Bbsl, SFG rickettsiae, Anaplasma phagocytophilum, TBE virus, Babesia microti and Bartonella henselae - have all been detected in field-collected ticks from the Nordic countries. Medical records were reviewed and questionnaires were completed to determine clinical manifestations. We found Lyme borreliosis to be the most common tick-transmitted infection as seen in 46 (54%) of the 86 participants with available medical records. Among the 86 participants with paired sera, serological or molecular evidence of recent exposure to other microorganisms than Bbsl could be demonstrated in eight (9%). Five participants (6%) exhibited serological evidence of recent concomitant exposure to more than one tick-borne microorganism. Clinical presentations were mild with one exception (TBE). In conclusion, our data suggest a low risk of infection with tick-borne microorganisms, other than Bbsl, in immunocompetent tick-bitten persons from the examined regions, a low occurrence of co-infection and mostly mild or no overt clinical signs of infection in immunocompetent persons exposed to the studied agents.

Rickettsioses in Denmark: A retrospective survey of clinical features and travel history.

Rickettsia spp. can be found across the globe and cause disease of varying clinical severity, ranging from life-threatening infections with widespread vasculitis to milder, more localized presentations. Vector and, to some degree, reservoir are hematophagous arthropods, with most species harboured by ticks. In Denmark, rickettsiae are known as a cause of imported travel-related infections, but are also found endemically in ticks across the country. Data are, however, lacking on the geographical origin and clinical features of diagnosed cases. In this study, we have examined the travel history and clinical features of two groups of patients; 1) hospital-patients diagnosed with rickettsioses in the years 2010-2015 and 2) patients from primary health care (PHC) centers in Denmark having demonstrated anti-rickettsia antibodies in the years 2012-2015. The patients were identified using the Danish National Patient Registry (DNPR) and through the serological database at the State Serum Institute, where the laboratory diagnosis of rickettsioses is currently centralized. Data were collected for 86 hospital patients and 26 PHC center patients by reviewing hospital medical records and performing telephone interviews with PHC centers. Of the hospital patients, 91% (78/86) had a history of international travel 14 days prior to symptom start, with most having imported their infection from southern Africa, South Africa in particular (65%), and presenting with a clinical picture most compatible with African tick-bite fever caused by R. africae. Only two patients presented with a CRP > 100 mg/L and no mortalities were reported. At the PHC centers, most patients presented with mild flu-like symptoms and had an unknown (50%) or no history (19%) of international travel, raising the possibility of endemic rickettsioses. In view of our findings, rickettsioses do not appear to constitute a major public health problem in Denmark, with most cases being imported infections and potential endemic cases presenting as mild infections.

[Talaromyces marneffei fungaemia in a patient from Thailand with newly diagnosed HIV].

Talaromyces marneffei is a dimorphic fungus, which may cause life-threatening opportunistic infections in immuno-compromised individuals. A 25-year-old woman from Thailand was admitted with fever, shortness of breath, cough, and weight loss. The symptoms had persisted for three weeks. The patient had a stopover in Copenhagen on her way to Thailand from Greenland. A thoracic X-ray showed bilateral interstitial changes. Examinations showed positive HIV-test with a CD4-count of 21/microlitre. Moreover, fungaemia with T. marneffei was detected by cultivation. Highly active antiretroviral therapy and IV amphotericin B treatment was initiated followed by perorally administrated itraconazole.

[Clinical manifestations, diagnosis and treatment of Lyme borreliosis].

Lyme borreliosis is an infection caused by the Borrelia burgdorferi sensu lato complex and transmitted by Ixodes ricinus ticks in Denmark. It can manifest itself in several different forms of which erythema migrans is the most common and is diagnosed by clinical assessment of the characteristic erythema. Laboratory support for the clinical diagnosis of other manifestations rests on the measurement of Borrelia-specific antibodies. Treatment is straight-forward with antibiotics such as penicillin. This paper reviews the clinical manifestations, diagnosis and treatment of this infection.

[Tick-borne infections in Denmark].

The castor bean tick, Ixodes ricinus, is common in woodlands in most of Denmark. Besides Borrelia burgdorferi, it can harbour a number of pathogenic microorganisms such as tick-borne encephalitis virus, Anaplasma phagocytophilum, Rickettsia helvetica, Francisella tularensis, Candidatus Neoehrlichia mikurensis, Bartonella spp., Borrelia miyamotoi and Babesia spp. These tick-borne infections should be a differential diagnostic consideration during the tick season in Denmark. We review the distribution, clinical manifestations, diagnosis and treatment of these microorganisms.

Bone morbidity in chronic myeloproliferative neoplasms.

Patients with the classical Philadelphia chromosome-negative chronic myeloproliferative neoplasms including essential thrombocythemia, polycythemia vera and primary myelofibrosis often suffer from comorbidities, in particular, cardiovascular diseases and thrombotic events. Apparently, there is also an increased risk of osteoporotic fractures among these patients. However, the true prevalence, mechanisms involved and therapeutic implications are not well described. In this review, we summarize what is currently known about possible associations between bone disease and chronic myeloproliferative neoplasms. Chronic inflammation has been suggested to explain the initiation of clonal development and progression in chronic myeloproliferative neoplasms. Decreased bone mineral density and enhanced fracture risk are well-known manifestations of many chronic systemic inflammatory diseases. As opposed to systemic mastocytosis (SM) where pathogenic mechanisms for bone manifestations probably involve effects of mast cell mediators on bone metabolism, the mechanisms responsible for increased fracture risk in other chronic myeloproliferative neoplasms are not known.

[New disease markers within the chronic myeloproliferative neoplasms]. / Nye sygdomsmarkører ved de kroniske myeloproliferative neoplasier.

The chaperone and calcium storing protein calreticulin is coded by CALR, and newly identified mutations in CALR are found in respectively 49-70% and 56-88% of JAK2- and MPL-negative patients with essential thrombocytaemia (ET) and primary myelofibrosis (PMF). A total of 41 mutations have been identified, all located to exon 9 which codes the protein's C-terminal. CALR mutations are present only in myeloid malignancies and confer a more indolent disease than JAK2-mutated ET and PMF. CALR mutations as a diagnostic and prognostic tool are promising and the mutations are potential targets for immune therapy.

[Status and perspectives on chronic myeloproliferative neoplasm treatment]. / Status og perspektiver for behandling af de kroniske myeloproliferative neoplasier.

Polycythaemia vera, essential thrombocytosis and primary myelofibrosis are closely related, clonal myeloproliferative neoplasms. Our knowledge of the underlying molecular mechanisms driving these diseases has increased dramatically during the latest ten years. Traditionally, treatment of these malignancies has focused on lowering their inherent thromboembolic risk but with the discovery of the JAK2-V617F mutation and most recently the calreticulin mutations new therapeutic options such as interferon-alpha, JAK2-inhibitors and statins are being contemplated. This article reviews these new treatment options.

Primary CNS lymphoma in a patient treated with azathioprine.

A 33-year-old man treated with azathioprine for 12 years for Crohn's disease presented with headache, nausea and vomiting accompanied by difficulty in putting words together and slight mental confusion. Prednisolone and antibiotics were without effect. MRI of the brain showed multiple focal lesions with surrounding oedema. There was cerebrospinal fluid pleocytosis, and Epstein-Barr virus (EBV) DNA was detected in the spinal fluid by PCR. A brain biopsy confirmed the suspicion of primary brain lymphoma. EBV-associated primary brain lymphoma is a relevant differential diagnosis in patients with long-standing immune suppression presenting with neurological symptoms. Detection of EBV DNA in the spinal fluid together with characteristic radiological findings may serve as a diagnostic clue for a quick diagnosis.