Babesia spp. and other pathogens in ticks recovered from domestic dogs in Denmark

Abstract

BackgroundNewly recognized endemic foci for human babesiosis include Europe, where Ixodes ricinus, a vector for several species of Babesia, is the most commonly identified tick. Vector-based surveillance provides an early warning system for the emergence of human babesiosis, which is likely to be under-reported at emerging sites. In the present study, we set out to screen I. ricinus collected from Danish domestic dogs for Babesia, in order to identify whether humans in Denmark are exposed to the parasite.FindingsA total of 661 ticks (Ixodes spp.) were collected from 345 Danish domestic dogs during April-September 2011 and pooled, one sample per dog. DNA was extracted from each sample and examined by PCR and sequencing for Rickettsia spp., Borrelia burgdorferi sensu lato, Bartonella spp., Francisella tularensis, Candidatus Neoehrlichia mikurensis, and Babesia spp. In total, 34% of the samples were positive for tick-borne microorganisms potentially pathogenic to humans: Rickettsia spp. were detected in 16% of the pools, with 79% being R. helvetica. Borrelia burgdorferi sensu lato was found in 15%, with the main species identified as Borrelia afzelii (39%). Likewise, 8% of the samples were positive for Babesia spp. (Babesia microti, 82%; Babesia venatorum (‘EU1’), 18%). Lastly, 1% of the samples tested positive for Candidatus Neoehrlichia mikurensis, and 0.6% for Bartonella spp. No ticks were found to be infected with Francisella tularensis.ConclusionsOur data are in support of endemic occurrence of potentially zoonotic Babesia in Denmark and confirms I. ricinus as a vector of multiple pathogens of public health concern.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-0843-0) contains supplementary material, which is available to authorized users.

Diversity of viruses in Ixodes ricinus, and characterization of a neurotropic strain of Eyach virus

“…Although ticks have the potential to transmit many different viruses, most studies surveying tick-borne pathogens in Europe have focused on bacterial and/or parasitic pathogens. Numerous reports detailing parasitic or bacterial prevalence in either European ticks or animal reservoirs are published every year [19] , [20] , [21] , [22] , [23] . For viruses however, the situation is completely different.…”

Detection of ‘Candidatus Neoehrlichia mikurensis’ and other Anaplasmataceae and Rickettsiaceae in Canidae in Switzerland and Mediterranean countries

“…In Switzerland, the prevalence of 'Candidatus Neoehrlichia mikurensis' in I. ricinus was estimated to be 6.4% in the western region and 3.5-8% in the eastern region of the country (Lommano et al, 2012;Maurer et al, 2013). The bacterium has also been detected in ticks in other European countries, including Germany, the Netherlands and Austria and pathogen specific DNA was detected in ticks collected from Danish and German dogs (Schreiber et al, 2014;Stensvold et al, 2015). Rodents may serve as a reservoir for 'Candidatus Neoehrlichia mikurensis'.…”

The Tick-Borne Diseases STING study: Real-time PCR analysis of three emerging tick-borne pathogens in ticks that have bitten humans in different regions of Sweden and the Aland islands, Finland

“…: 16.1% T. gondii: 23%) [14,13]. Interestingly, these pathogens have been found in I. ricinus collected in Poland [9] and Denmark [7]. Due to the larger sample size in this study, it is likely that the prevalence of these pathogens in I. ricinus from South Central and Southernmost Sweden and the Åland islands, Finland is considerably lower.…”

“…The lack of Bartonella in Norway [31] and Finland [32] supports that tick-borne Bartonella spp. might not tolerate the harsher climate in most of the Nordic countries compared to Denmark [7]. There are no previously published data on the prevalence of T. gondii in neither blood-feeding nor questing ticks from the Nordic countries.…”

“…These pathogens have been detected within Ixodes ricinus in neighboring countries (Table 1) such as Germany (F. tularensis) [6], Denmark (Bartonella spp.) [7] and Poland (T. gondii) [8,9]. Since infection with F. tularensis subspecies (ssp.)…”