Case report: first symptomatic Candidatus Neoehrlichia mikurensis infection in Slovenia

Background Candidatus Neoehrlichia mikurensis (CNM) is an emerging tick-born pathogen and usually causes symptomatic infection only in immunocompromised patients. Apart from one described case found in the literature where cultivation was successful, all cases so far were diagnosed by using broad-range 16S rDNA PCR. Case presentation Our patient presented with a prolonged febrile state of unknown origin. Clinical presentation, extensive medical workup and classic microbiologic testing were non-conclusive. Several infectious agents and other causes for the febrile state were excluded. In the end, a broad-range 16S rDNA PCR was to be performed to confirm the diagnosis of CNM infection. Treatment was successful with doxycycline. Conclusions Due to the obscurity of the pathogen, diagnostic workup in CNM is prolonged and challenging. More awareness is need about this emerging infectious disease in countries with high prevalence of tick-borne diseases as standard microbiological methods are not successful in confirming the diagnosis.

A brief review: the prevalence of tick-borne pathogens in urban and suburban areas

Ticks are widely distributed blood-sucking ectoparasites and vectors for numerous zoonotic pathogens that cause infectious diseases in humans and animals. The increase in the incidence of tick-borne diseases (TBD) is partially associated with climatic changes, such as shorter and warmer winters, prolonged growing seasons, and also with increasing urbanisation. In recent decades, a rising number of established populations of medically important ticks have been reported in urban and suburban areas such as city parks or suburban forests over many regions in Europe. The transformation of natural ecosystems into urban areas becomes actual significant problem because it could affect the circulation of tick-borne pathogens and increase the risk of infection for humans and domestic animals. Tick-borne pathogens, including Borrelia burgdorferi s. l., Rickettsia spp., Anaplasma phagocytophilum, Candidatus Neoehrlichia mikurensis, and Babesia spp., have been detected in urban tick populations in Europe. Such places as parks, leisure-time areas, green spaces, and gardens become endemic zones of tick-borne pathogens. This review describes the investigations on the prevalence of tick-borne pathogens in urbanised areas conducted in Europe during the last fifteen years (2005–2020).

Correction to: Detection of Candidatus Neoehrlichia mikurensis in Norway up to the northern limit of Ixodes ricinus distribution using a novel real time PCR test targeting the groEL gene

After publication of our article [1] it came to our notice that the source of the sequence for the control plasmid, pNeo (Materials and methods: Controls) was incorrectly stated as AB094461. The correct accession number is AB074461. The authors apologize for any confusion this may have caused.

Monitoring of vector-borne diseases in the west part of Ukraine

During recent years, infectious and invasive animal diseases caused by viruses, bacteria, and protozoa and transmitted by ticks have been a new problem in medical and veterinary practice. Many of these diseases are zoonoses and lead to the disability and mortality of humans and animals. Ixodes ricinus and Dermacentor reticulatus are species of ticks that are commonly attack animals and humans in Europe. These ticks are spread throughout the EU and are involved in the transmission of a large number of vector-borne diseases. To date, relatively limited data on the circulation of tick-borne diseases and their transmission in western Ukraine are presented. The purpose of this study was to monitor the types of ixodid ticks, as well as to identify pathogens in ticks collected from the environment in urban parks and from dogs and cats. A total of 215 ticks (22 Ixodes ricinus and 193 Dermacentor reticulatus) collected in two regions of Lviv and Ivano-Frankivsk were investigated. Pathogens, namely, Rikettsia spp., Candidatus Neoehrlichia mikurensis, Anaplasma phagocytophilum and Bartonella spp., were detected in 64.0% of the I. ricinus ticks. Overall, 18.2% of I. ricinus ticks were positive for Rikettsia spp., 54.5% for Candidatus Neoehrlichia mikurensis, 9.1% for A. phagocytophilum and Bartonella spp. confirmed in 4.5% of the studied ticks. Mixed infestations were found in 5 samples of I. ricinus DNA, representing 22.7%. In addition, 74.6% of D. reticulatus ticks were infested with these pathogens. Overall, 30.0% of D. reticulatus ticks were positive for Rikettsia spp., Candidatus Neoehrlichia mikurensis was confirmed in 54.9%, A. phagocytophilum in 1.6%, and Bartonella spp. in 6.2% of the studied ticks. Mixed infestations were found in 35 D. reticulatus DNA samples, representing 18.1%. The prevalence of Rikettsia spp. in two regions of Lviv and Ivano-Frankivsk, among the studied ticks was 28.8%, Bartonella spp. – 6.0%, A. phagocytophilum – 2.3%, Candidatus Neoehrlichia mikurensis – 54.9%. Our data indicate the presence of pathogens in urban populations of ticks of I. ricinus and D. reticulatus in west part of Ukraine. Monitoring of tick-borne diseases is an important tool in the prevention and control of infections transmitted to humans and animals.