Differentiating Lyme arthritis: a case-based review.

The incidence or prevalence of Lyme arthritis (LA) in Denmark is unknown and assumed very low. No published cases of polymerase chain reaction (PCR)-confirmed LA from Denmark exist. Clinically, LA does not differ from other rheumatic oligoarthritic disorders posing a differential diagnostic challenge. To review the incidence and prevalence of LA to our knowledge and to present a case series of PCR-confirmed LA cases from Denmark. We conducted a systematic literature review via MEDLINE and EMBASE to explore incidence and prevalence rates of LA. Additionally, we present six cases of patients diagnosed with LA in Denmark. Our literature review identified 23 studies reporting prevalence or incidence, yet only ten studies provided estimates ranging from 1.1 to 280/100.000 in the general population. Our case series identified six patients with LA from a localized region in Southern Denmark; all confirmed by Borrelia-specific real-time PCR from synovial fluid. The diagnostic delay was up to 38 months. All patients except one had a history of previous tick bites; none had erythema migrans lesions. All presented with recurrent arthritis in the knee joint, and two had arthritis in the wrist. The literature review showed an incidence of LA ranging from 1.1 to 15.8 per 100.000 in Europe. Our case series suggests a potentially higher prevalence of LA in Denmark than previously believed. Lack of tick exposure history, antibody assessments and test of Borrelia burgdorferi sensu lato DNA in synovial fluid might lead to misdiagnosed cases potentially explaining the assumed low incidence of LA in Denmark.

Contaminated dicloxacillin capsules as the source of an NDM-5/OXA-48-producing Enterobacter hormaechei ST79 outbreak, Denmark and Iceland, 2022 and 2023.

From October 2022 through January 2023, nine patients with NDM-5/OXA-48-carbapenemase-producing Enterobacter hormaechei ST79 were detected in Denmark and subsequently one patient in Iceland. There were no nosocomial links between patients, but they had all been treated with dicloxacillin capsules. An NDM-5/OXA-48-carbapenemase-producing E. hormaechei ST79, identical to patient isolates, was cultured from the surface of dicloxacillin capsules in Denmark, strongly implicating them as the source of the outbreak. Special attention is required to detect the outbreak strain in the microbiology laboratory.

Detection of Borrelia burgdorferi sensu lato DNA in cerebrospinal fluid samples following pre-enrichment culture.

Molecular methods for diagnosing Lyme neuroborreliosis (LNB) have shown suboptimal diagnostic sensitivities. The objective of this study was to improve the clinical sensitivity of PCR detection of Borrelia burgdorferi sensu lato spirochetes by inoculating cerebrospinal fluid (CSF) from patients suspected of LNB directly into culture medium at the time of lumbar puncture, with this pursuing enrichment of Borrelia spirochetes before PCR analysis. Adult patients with symptoms suggestive of LNB were prospectively enrolled at two hospitals in the Region of Southern Denmark. The CSF-culture samples were incubated for at least eight weeks. During this period, culture sample aliquots were analysed for the presence of Borrelia DNA by separate PCR protocols in two independent clinical laboratories. The included patients were diagnosed with definite (n=12) or possible (n=2) LNB, and non-LNB (n=171) based on clinical and paraclinical findings. Patients in the LNB and the non-LNB group had a median duration from symptom onset to lumbar puncture of 40 days (IQR [23-90] days) and 120 days (IQR [32-365] days), respectively. Pre-enrichment growth of Borrelia spirochetes was accomplished from three patients (21 %) in the LNB group. The positive culture samples were confirmed by both the digital droplet PCR and the real-time PCR methods employed. All CSF samples were PCR negative in the non-LNB group. The results of this study do not support the use of Borrelia-specific PCR as a general routine diagnostic tool in adults. Still, they suggest it may prove of additional value in selected patients with a limited time from symptom onset to sample collection.

Continued expansion of tick-borne pathogens: Tick-borne encephalitis virus complex and Anaplasma phagocytophilum in Denmark.

Tick-borne encephalitis virus (TBEV) is a tick-transmitted flavivirus within the tick-borne encephalitis (TBE) complex. The TBE complex is represented by both TBEV and louping ill virus (LIV) in Denmark. Anaplasma phagocytophilum is also transmitted by ticks and is believed to play an essential role in facilitating and aggravating LIV infection in sheep. This study aimed to describe the distribution of TBE complex viruses in Denmark, to establish the possible emergence of new foci and their association with the distribution of A. phagocytophilum. We performed a nationwide seroprevalence study of TBE complex viruses using roe deer (Capreolus capreolus) as sentinels and determined the prevalence of A. phagocytophilum in roe deer. Danish hunters obtained blood samples from roe deer during the hunting season of 2013-14. The samples were examined for TBEV-specific antibodies by virus neutralization tests (NT). A. phagocytophilum infection was assessed by specific real-time-PCR. The overall seroprevalence of the TBE complex viruses in roe deer was 6.9% (51/736). The positive samples were primarily obtained from a known TBE endemic foci and risk areas identified in previous sentinel studies. However, new TBE complex risk areas were also identified. The overall prevalence of A. phagocytophilum was 94.0% (173 PCR-positive of 184 roe deer), which is twice the rate observed ten years ago. These results point to an expansion of these tick-borne diseases geographically and within reservoir populations and, therefore, rationalize the use of sentinel models to monitor changes in transmission of tick-borne diseases and development of new risk areas. We found no association between TBE complex-positive roe deer and the prevalence of A. phagocytophilum, as almost all roe deer were infected. Based on our findings we encourage health care providers to be attentive to tick-borne illnesses such as TBE when treating patients with compatible symptoms.