Tick-borne Pathogens Detected in the Blood of Immunosuppressed Norwegian Patients Living in a Tick-endemic Area.

BACKGROUND: The knowledge regarding the occurrence and the clinical implications of tick-borne infections in immunosuppressed patients living in tick-endemic areas is limited. METHODS: Adult patients with autoimmune conditions requiring immunosuppressive treatment such as infliximab and rituximab were invited to participate in the study when they attended the hospital for treatment and/or control of the disease. Whole-blood samples were analyzed by real-time polymerase chain reaction for Borrelia burgdorferi sensu lato, Borrelia miyamotoi, Anaplasma phagocytophilum, Rickettsia spp., Candidatus Neoehrlichia mikurensis, and Babesia spp. RESULTS: The occurrence of tick-borne pathogens in the blood of patients (n = 163) with autoimmune conditions requiring immunosuppressive treatment was evaluated. Pathogen DNA was detected in 8.6% (14/163) of the patients. The predominant pathogen was Ca. Neoehrlichia mikurensis (12/14), which was carried in the blood of infected patients for 10-59 days until treatment with doxycycline. B. burgdorferi s.l. and Rickettsia spp. were detected in 1 patient each. The B. burgdorferi-infected patient presented with fever, whereas the remaining patients were judged to have subclinical infections. B. miyamotoi, A. phagocytophilum, and Babesia spp. were not detected in any patient. CONCLUSIONS: Patients treated with biologicals and living in a tick-endemic area seem to have a high risk of contracting Ca. Neoehrlichia mikurensis infection, which, if left untreated, could result in thromboembolic complications.

Does more favourable handling of the cerebrospinal fluid increase the diagnostic sensitivity of Borrelia burgdorferi sensu lato-specific PCR in Lyme neuroborreliosis?

BACKGROUND: Tests for direct detection of Borrelia burgdorferi sensu lato (Bb) in Lyme neuroborreliosis (LNB) are needed. Detection of Bb DNA using PCR is promising, but clinical utility is hampered by low diagnostic sensitivity. We aimed to examine whether diagnostic sensitivity can be improved by the use of larger cerebrospinal fluid (CSF) volumes and faster handling of samples. METHODS: Patients who underwent CSF examination for LNB were included. We collected two millilitres of CSF for PCR analysis, extracted DNA from the pellets within 24 h and analysed the eluate by two real-time PCR protocols (16S rRNA and OspA). Patients who fulfilled diagnostic criteria for LNB were classified as LNB cases and the rest as controls. RESULTS: Bb DNA in CSF was detected by PCR in seven of 28 adults with LNB. Two were Bb antibody negative. No Bb DNA was detected in CSF from 137 controls. Diagnostic sensitivity was 25% and specificity 100%. There was a non-significant trend towards larger CSF sample volume, faster handling of the sample, shorter duration of symptoms, and higher CSF cell count in the PCR-positive cases. CONCLUSION: We did not find that optimized handling of CSF increased diagnostic sensitivity of PCR in adults with LNB. However, our case series is small and we hypothesize that the importance of these factors will be clarified in further studies with larger case series and altered study design. PCR for diagnosis of LNB may be useful in cases without Bb antibodies due to short duration of symptoms.

Lyme neuroborreliosis: do we treat according to guidelines?

Evidence-based guidelines, published in 2010, equate the efficacy of oral and intravenous antibiotics and recommend treatment duration of 2 weeks in early Lyme neuroborreliosis (LNB) without encephalitis or myelitis. Further, the Norwegian health authorities give a general advice to choose oral rather than intravenous administration when proven effective, due to lower costs, fewer risks, and reduced patient inconvenience. In this study we aimed to chart LNB treatment practice in Norway and compare it to these recommendations. Adult patients diagnosed with definite LNB between 2007 and 2013 in 11 different hospitals in the four health regions in Norway were invited to answer a questionnaire regarding duration and administration of antibiotic treatment. A total of 253 patients answered. Median age at diagnosis was 59 years (range 19-83), and 125 (49%) were women. Duration of treatment was 1 week in 7 (3%) patients, 2 weeks in 81 (32%), 3 weeks in 62 (25%), 4 weeks in 48 (19%), 5 weeks in 12 (5%), ≥6 weeks in 29 (12%), and unknown in 14 (6%). Treatment was given orally in 77 (30%) patients, intravenously in 110 (44%), both orally and intravenously in 65 (26%), and unknown in one. Treatment practices differed between the health regions (p = 0.002). During the study period, there were no significant time trend neither with respect to proportion of patients treated for only 2 weeks (OR 0.899, p = 0.109) nor with respect to proportion of patients treated exclusively with oral antibiotics (OR 1.131, p = 0.074). In conclusion, there seem to be a gap between evidence-based recommendations and treatment practice of LNB in Norway.