Multiple Tick-Borne Pathogens in Ixodes ricinus Ticks Collected from Humans in Romania.

Zsuzsa Kalmár,Ioana Adriana Matei,Mirabela Oana Dumitrache,Mihaela Lupșe,Călin Mircea Gherman,Gianluca D’Amico,Andrei Daniel Mihalca,Angela Monica Ionică

doi:10.3390/pathogens9050390

Abstract

Ticks are medically important vectors of infectious diseases that are able to transmit pathogens to humans and animals. Tick-borne diseases represent a major health concern, posing an increasing risk to the public health during the last century and affecting millions of people. The aim of the current study was to provide epidemiological data regarding the presence of certain tick-borne pathogens in ticks feeding on humans in Romania. Overall, 522 Ixodes ricinus ticks collected from humans were screened for six pathogens: Borrelia spp., Neoehrlichia mikurensis, Babesia spp., Coxiella spp., Bartonella spp., and Francisella tularensis. Ticks attached to humans were collected between 2013–2015 in Cluj County, Romania. Conventional, nested and quantitative PCR were used to detect specific genetic sequences of each pathogen. For identifying the infectious agents, positive samples were sequenced. The infection prevalence was 21.07% from which 8.18% were mixed infections. The detected agents were Borrelia spp., N. mikurensis and Babesia spp. The present data reveal the endemic occurrence of potentially zoonotic pathogens in Romania. Revealing the current distribution of tick-borne pathogens in ticks collected from humans may provide new insights in understanding the complex ecology of tick-borne diseases and enlightens current knowledge about the infection prevalence at local, regional and national levels.

Highlights

Ticks of the Ixodidae family have medical and veterinary importance worldwide, mainly due to the transmission of tick-borne pathogens [1]
The only study with a large dataset elaborated in Romania has evaluated the infection prevalence of B. burgdorferi s.l. in ticks collected from humans and in patients bitten by Borrelia-positive ticks [4,5]
According to the morphological keys [9], a total of 522 ticks collected from humans were identified as I. ricinus

Summary

Introduction

Ticks of the Ixodidae family have medical and veterinary importance worldwide, mainly due to the transmission of tick-borne pathogens [1]. The risk of acquiring infections with tick-borne pathogens is determined by the abundance of ticks in the specific geographical location, the density of reservoir hosts and the prevalence of infection in ticks and hosts [2]. Monitoring tick-borne pathogens in certain geographical areas is of particular importance to assess the fluctuation of human infection risks. Studies conducted in Romania have evaluated the prevalence of Borrelia spp., N. mikurensis, Anaplasma spp., and Rickettsia spp. in I. ricinus [4,5,6,7,8]. The only study with a large dataset elaborated in Romania has evaluated the infection prevalence of B. burgdorferi s.l. in ticks collected from humans and in patients bitten by Borrelia-positive ticks [4,5]

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Discussion

Conclusion