Laboratory findings in tick-borne relapsing fever

  • Homayoun Sadeghi-Bazargani
  • Shahnam Arshi Shahid Beheshti University of Medical Sciences
  • Mehdi Asmar Department of Parasitology, Pasteur Institute of Iran, Pasteur Ave, Tehran 13164, Iran
  • Manuchehr Barak Department of Pediatrics, Ardabil University of Medical Sciences, Ardabil, Iran
Keywords: Relapsing fever, Tick-borne, Borrelia persica, Spirochetal infections, Laboratory findings, ESR


Purpose: To investigate some laboratory findings in tick-borne  relapsing fever.

Methods: A large screening program was conducted in Ardabil Province of Iran to screen 2201 patients who referred with fever to health houses and clinics in Khalkhal, Kosar and Nir districts for a positive smear of tick-borne  relapsing fever. Other cases explored in system or by the private clinics were also enrolled. Hematological and biochemical assays were done for the patients with relapsing fever and for healthy controls.

Results: Fifty-four percent of the participants were males and 46% were female participants. The median age of the participants was 20(IQR=32) years. Mean white blood cell count(WBC) was 6655 in control group versus 10083 in relapsing fever group(P<0.001). Mean hemoglubin was 13.7 g/dl in control group versus 11.6 g/dl in relapsing fever group(P<0.01). Mean MCHC(mean cell hemoglobin concentration) was 34.1 in control group versus 32.5 in relapsing fever group(P<0.001). Mean 1st hour erythrocyte sedimentation rate (ESR) was 7.8 in control group versus 58.9 in relapsing fever group(P<0.001). Mean 2nd hour ESR was 16 in control group versus 63.4 in relapsing fever group(P<0.001). Other parameters were not found to be statistically different between groups. After controling for age and gender, only the first hour ESR and second hour ESR remained statistically significant, while white blood cell count had a tendancy to being different between relapsing fever and control group subjects.

Conclusion:  Some hematological parameters such as white blood cell count, hemoglubin, MCHC and erythrocyte sedimentation rate were found to be possibly affected by relapsing fever, while other laboratory measurements didn’t appear to be affected by disease.



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