Tick-borne pathogens in tick species infesting humans in Sibiu County, central Romania

Parasitol Res. 2018 May;117(5):1591-1597. doi: 10.1007/s00436-018-5848-0. Epub 2018 Mar 28.

Abstract

Romania has a highly diverse tick fauna. Consequently, a high diversity of tick-transmitted pathogens might be a potential threat to humans. However, only a limited number of tick species regularly infest humans, and pathogens present in such species are therefore of particular interest from a medical perspective. In this study, 297 ticks were collected from humans during 2013 and 2014. Ixodes ricinus was the predominant tick species, accounting for 272 specimens or 91.6% of the ticks in the study. Nevertheless, other tick species were also found to infest humans: Dermacentor marginatus constituted 7% of the ticks found on humans (21/297), Haemaphysalis punctata 1% (3/297), and Haemaphysalis concinna 0.3% (1/297). Ticks were tested by PCR for a wide range of tick-borne pathogens. In total, 11.8% of the ticks carried human pathogenic bacteria, while no viral or protozoan pathogens were detected. The most frequently detected pathogen was Rickettsia spp., occurring in 5.4% of the ticks (16/297) and comprising three species: Rickettsia (R.) raoultii, R. monacensis, and R. helvetica. Borrelia s.l. occurred in 3% (9/297) of the ticks. "Candidatus Neoehrlichia mikurensis" occurred in 1.7% (5/297) and Anaplasma phagocytophilum in 1.3% (4/297). Anaplasma bovis was detected in an H. punctata and Borrelia miyamotoi in an I. ricinus. These results point to the need for further studies on the medical importance of tick-borne pathogens in Romania.

Keywords: Humans; Romania; Sibiu County; Tick-borne diseases; Ticks.

MeSH terms

  • Anaplasma phagocytophilum / isolation & purification*
  • Animals
  • Borrelia / isolation & purification*
  • Dermacentor / microbiology*
  • Female
  • Humans
  • Ixodes / microbiology*
  • Male
  • Rickettsia / isolation & purification*
  • Romania / epidemiology
  • Tick Infestations / epidemiology*