Human babesiosis.

Babesiosis is a less common but important tick-borne infectious disease. Over the last 50 years, an increasing number of cases have been reported worldwide, especially in the USA. The northern part of the US is an endemic area where the incidence has risen to 2,000 cases per year in the last decade. Babesia microti, a parasite of small rodents, is the cause of most of these infections in that region. In Europe, 56 autochthonous cases of human babesiosis have been reported since 1957. Most of them were caused by the species Babesia divergens, a parasite of cattle. Since 1992, 13 cases of B. microti infection have been imported from North America into Europe. The disease is serious especially for splenectomised and immunocompromised patients. Although the most important vector of babesiosis in Europe is the tick Ixodes ricinus, infection was transmitted through blood transfusion in number of patients, which can be fatal for immunosuppressed patients. The diagnosis of babesiosis is based on the identification of intraerythrocytic parasites in a blood smear, PCR detection of Babesia DNA, and determination of antibodies by serology and immunofluorescence assays. The disease is treated with antibiotics (azithromycin or clindamycin in a severe course of the disease) and quinine. The increase in human babesiosis is not only due to climate change and tick activity, outdoor leisure activities, and increased human migration, but an important role is also played by improved molecular methods and growing awareness of the disease.

Borrelia burgdorferi sensu lato infection in Ixodes ricinus ticks in urban green areas in Prague.

Ixodes ricinus ticks are considered as the vector of the Borrelia burgdorferi sensu lato complex in urban areas, including city parks and green recreational areas. The aim of the present study was to determine the prevalence of B. burgdorferi s. l. in urban areas in the city of Prague, Czech Republic. In selected public green areas in Prague, a total of 2819 I. ricinus ticks were collected in spring, from April to June, in 2014-2020. Quantitative real time PCR revealed 28.1% of ticks (31% of males, 33.7% of females and 25.8% of nymphs) to be positive for B. burgdorferi s. l. The prevalence varied significantly (p˂0.01) between collection sites, with the highest numbers of infected ticks found in the central city areas. The places serving people for recreational and sport activities in urban areas are characterized by a lower diversity of reservoir hosts, provide opportunity for exposure to Borrelia infected ticks, and pose a higher infection risk. We have detected seven Borrelia species in ticks: B. garinii, B. afzelii, B. bavariensis, B. burgdorferi sensu stricto, B. valaisiana, B. spielmanii, and B. finlandensis. Most positive ticks were infected by B. garinii (35%) and B. afzelii (36.9%). Our results show that the Borrelia transmission cycle occurs within urban biotops and highlight the need for surveillance of tick-borne pathogens in public green areas.

Molecular and serological evidence of Borrelia burgdorferi sensu lato in wild rodents in the Czech Republic.

The aim of the present study was to determine the frequency and spatial distribution of the Borrelia species in wild rodents in the Czech Republic. In total, 293 muscle tissue samples and 106 sera from 293 wild rodents captured in North Bohemia and North-East and South Moravia were examined for the presence of Borrelia spp. and antibodies. Muscle samples were investigated with real-time polymerase chain reaction (PCR) with a recA primer set, with DNA quantification and melting curve analysis, and with restriction fragment length polymorphism (RFLP) analysis of the 5S-23S rDNA intergenic spacer. Infection with Borrelia burgdorferi sensu lato was found in 16.4% of the muscle samples. The most abundant genospecies was Borrelia afzelii (11.3%), followed by Borrelia burgdorferi sensu stricto (4.8%) and Borrelia garinii (0.7%). Borrelia infection was more frequently observed in Clethrionomys glareolus than in Apodemus spp. Sera were analyzed with an enzyme-linked immunosorbent assay (ELISA) test, yielding the total seropositivity rates of 24.5% for anti-Borrelia IgM antibodies and 25.5% for IgG antibodies. Total seroprevalence was higher in Apodemus spp. than in C. glareolus. In conclusion, our data indicate that in the Czech Republic small wild rodents can serve as hosts for B. burgdorferi s. s. as well as for B. afzelii.