First Record of a Suspected Human-Pathogenic Borrelia Species in Populations of the Bat Tick Carios vespertilionis in Sweden.

Thomas G T Jaenson,Peter Wilhelmsson

doi:10.3390/microorganisms9051100

Thomas G T Jaenson, Peter Wilhelmsson

Open Access

https://doi.org/10.3390/microorganisms9051100

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Abstract

The bat tick Carios vespertilionis has been reported from Sweden to occasionally feed on humans resulting in disease symptoms. The aim of this study was to investigate C. vespertilionis as a potential vector and reservoir of Borrelia species. In 2015 and 2018 in south-central Sweden, C. vespertilionis ticks were collected from a wooden bat box harboring Soprano pipistrelle bats, Pipistrellus pygmaeus. In addition, one C. vespertilionis tick found inside a house in southern Sweden in 2019 was collected. Ticks were screened for Borrelia spp. using a genus-specific quantitative PCR assay. The Borrelia species of the positive specimens were determined by conventional PCR followed by DNA sequencing and phylogenetic analyses. A total of 24% (22 of 92) of the analyzed C. vespertilionis ticks were Borrelia-positive. Phylogenetic analyses indicate that the bacteria belong to the relapsing fever group of borreliae; some of them appear to be identical with Borrelia sp. CPB1, a spirochete only found twice before—in the United Kingdom and in France. Our results also indicate a temporal and spatial distribution of this Borrelia species. Since C. vespertilionis occasionally bites humans, and since it exhibits a high prevalence of Borrelia bacteria, it is possible that it presents a risk of human disease. Further studies are needed to characterize Borrelia sp. CPB1 to determine if it is human-pathogenic and to determine if C. vespertilionis is a vector and/or reservoir of this agent.

Highlights

The main reasons for this are the severe outbreaks in humans by viruses related to or identical with batassociated viruses, i.e., coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), Ebola, bat lyssavirus rabies and Nipah [2,3,4,5,6,7]
In the summers of 2015 and 2018, at Snesslinge (60◦ 19.567 N, 18◦ 15.067 E, Figure 1), province of Uppland, south-central Sweden, 91 ticks were collected from a water-filled tray placed below a wooden bat box harboring an estimated number of 250–500 adult females and young,
Between June and August in the summers of 2015 and 2018 in the province of Uppland, a total of 91 ticks (31 larvae, 48 nymphs and 12 adults) were collected from a water-filled tray placed below a wooden bat box

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Many different species of putative or proven vertebrate-pathogenic parasites, bacteria, and viruses have been detected in bats and bat-associated ectoparasites, ticks (Ixodida, Ixodidae, and Argasidae). Investigations of bat-associated microorganisms and viruses have drastically increased during the last two decades [1]. The main reasons for this are the severe outbreaks in humans by viruses related to or identical with batassociated viruses, i.e., coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), Ebola, bat lyssavirus rabies and Nipah [2,3,4,5,6,7]

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