Classification of patients referred under suspicion of tick-borne diseases, Copenhagen, Denmark

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To provide better care for patients suspected of having a tick-transmitted infection, the Clinic for Tick-borne Diseases at Rigshospitalet, Copenhagen, Denmark was established. The aim of this prospective cohort study was to evaluate diagnostic outcome and to characterize demographics and clinical presentations of patients referred between the 1st of September 2017 to 31st of August 2019. A diagnosis of Lyme borreliosis was based on medical history, symptoms, serology and cerebrospinal fluid analysis. The patients were classified as:

  • definite Lyme borreliosis
  • possible Lyme borreliosis
  • post-treatment Lyme disease syndrome

Antibiotic treatment of Lyme borreliosis manifestations was initiated in accordance with the national guidelines. Patients not fulfilling the criteria of Lyme borreliosis were further investigated and discussed with an interdisciplinary team consisting of specialists from relevant specialties, according to individual clinical presentation and symptoms. Clinical information and demographics were registered and managed in a database. A total of 215 patients were included in the study period. Median age was 51 years (range 17-83 years), and 56 % were female.

Definite Lyme borreliosis was diagnosed in 45 patients, of which:

  • 20 patients had erythema migrans
  • 14 patients had definite Lyme neuroborreliosis
  • six had acrodermatitis chronica atrophicans
  • four had multiple erythema migrans
  • one had Lyme carditis
  • 12 patients were classified as possible Lyme borreliosis
  • 12 patients as post-treatment Lyme disease syndrome
A total of 146 patients (68 %) did not fulfil the diagnostic criteria of Lyme borreliosis.
  • Half of these patients (73 patients, 34 %) were diagnosed with an alternative diagnosis including inflammatory diseases, cancer diseases and two patients with a tick-associated disease other than Lyme borreliosis.

A total of 73 patients (34 %) were discharged without sign of somatic disease.

Lyme borreliosis patients had a shorter duration of symptoms prior to the first hospital encounter compared to patients discharged without a specific diagnosis (p<0.001). When comparing symptoms at presentation, patients discharged without a specific diagnosis suffered more often from general fatigue and cognitive dysfunction.

In conclusion, 66 % of all referred patients were given a specific diagnosis after ended outpatient course. A total of 32 % was diagnosed with either definite Lyme borreliosis, possible Lyme borreliosis or post-treatment Lyme disease syndrome; 34 % was diagnosed with a non-tick-associated diagnosis. Our findings underscore the complexity in diagnosing Lyme borreliosis and the importance of ruling out other diseases through careful examination.



While Lyme isn’t everything, it CAN BE anything.  This paper shows once again that half are turned away due to strict diagnostic criteria utilizing faulty serology testing where few are positively diagnosed. They are slapped with a label that will keep them from proper treatment and are doomed to a life of misery.

Nothing new here.  Same song, different day.

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