Reservoir role of lizard Psammodromus algirus in transmission cycle of Borrelia burgdorferi sensu lato (Spirochaetaceae) in Tunisia

To investigate the reservoir role of the lizard Psammodromus algirus for the Lyme disease spirochete, 199 lizards were trapped from April to October 2003 in El Jouza, northwestern Tunisia. In this site, the infection rate of free-living Ixodes ricinus (L.) by Borrelia was evaluated by immunofluorescence as 34.6% for adult ticks and 12.5% for nymphs. Eighty percent of P. algirus (117/146) captured during this study were infested by I. ricinus, the predominant tick species collected from lizards. The intensity of tick infestation of this host by larvae and nymphs ranged from 0.14 to 7.07 and from 1.5 to 6.58, respectively. These immature stages of I. ricinus were found on lizards in spring and the beginning of summer, with a peak of intensity during June (10.16 immature ticks by lizard). Tissue cultures from lizards and xenodiagnosis with larval I. ricinus were used to assess the infection and the ability, respectively, of infected lizards to transmit Borrelia to naive ticks. Seventeen percent of xenodiagnostic ticks (40/229) acquired B. lusitaniae while feeding on P. algirus. Therefore, we demonstrated the ability of the lizards to sustain Borrelia infection and to infect attached ticks, and we proved that P. algirus is a reservoir host competent to transmit B. lusitaniae.     

Borrelia burgdorferi sensu lato infection in larval Ixodes ricinus (Acari: Ixodidae) feeding on blackbirds in northwestern Italy

Birds belonging to 59 species (n = 1,206) were live captured in Piemonte, northwestern Italy, in 2001. Ixodes ricinus (L.) larvae were collected from 59 birds belonging to nine species, and nymphs were recovered on 79 birds belonging to 10 species. Eurasian blackbirds, Turdus merula L., had significantly higher levels of infestation by ticks than other passerine species. Larval I. ricinus of blackbirds peaked in summer, when prevalence was 39% (95% confidence interval 24.2-55.5) and mean number of ticks per host was 3.3 (1.6-7.2), whereas nymphs peaked in spring, when prevalence was 72.2% (54.8-85.8) and mean number of ticks per host was 6.9 (4.4-10.7). Immature I. ricinus were coincidentally aggregated on blackbirds, with 15 blackbirds feeding 67.4% of nymphs and 40.3% of larvae, and coinfestation by both stages was relatively high in summer: Kappa = 0.64 (0.40-0.88). Borrelia burgdorferi sensu lato was identified by polymerase chain reaction (PCR) in 58.3% (35.9-78.5) of larvae with engorgement ratio > or = 3 that were collected from blackbirds. Larvae that were collected from other passerine species gave negative PCR results. Sixteen of 21 PCR-positive samples belonged to B. garinii (76.2%), and five (23.8%) were Borrelia valaisiana. Results of this study suggest that blackbirds play an important role as hosts for immature I. ricinus and as reservoir of Borrelia garinii in northwestern Italy.     

Borrelia lusitaniae and spotted fever group rickettsiae in Ixodes ricinus (Acari: Ixodidae) in Tuscany, central Italy

Prevalence of infection by Borrelia burgdorferi s.l. and spotted fever group (SFG) rickettsiae was estimated in host-seeking ticks in an area in Tuscany, central Italy, where Lyme borreliosis was reported in a forestry worker. B. burgdorferi s.l. was identified by polymerase chain reaction in 16.7% (95% CI = 10.3, 24.8) of Ixodes ricinus (L.) nymphs and 39.6% (95% CI = 26.5, 54.0) of adults. Borrelia lusitaniae accounted for 82.9% of positive samples, followed by Borrelia garinii (9.8%), Borrelia afzelii (2.4%), and Borrelia burgdorferi s.s. (2.4%). One Rhipicephalus spp. adult was infected with B. garinii (prevalence = 8.3%; 95% CI = 0.21, 38.5). Prevalence of infection by SFG rickettsiae was 38.5% (95% CI = 26.7, 51.4) in I. ricinus nymphs, 34.6% (95% CI = 22.0, 49.1) in I. ricinus adults, and 50% (95% CI = 21.1, 78.9) in Rhipicephalus spp. adults. Phylogenetic analysis showed the similarity of B. lusitaniae strains that were identified in this study and of a strain that was previously isolated from a human patient in Portugal. Results of this study confirm the dominance of B. lusitaniae in areas in the Mediterranean basin and the infection by SFG rickettsiae in I. ricinus.     

Borrelia burgdorferi sensu stricto in yellow-necked mice and feeding Ixodes ricinus ticks in a forest habitat of west central Poland

Wild rodents and the subadult Ixodes ricinus (L.) ticks infesting them were examined for the presence of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner s.l. in a sylvatic habitat in west central Poland during May-September 2002. In total, 818 feeding ticks were recovered from 73 infested yellow-necked mice, Apodemus flavicollis Melchior; in addition, bank voles, Clethrionomys glareolus Schreber, were rarely captured and proved to be weakly parasitized. Only 2.7% of A. flavicollis and 2.2% of 320 engorging larvae were polymerase chain reaction (PCR) positive for the bacterium. All spirochete-PCR-positive samples yielded exclusively B. burgdorferi s.s. This genospecies was also the most prevalent in questing nymphs and accounted for 87.5% of the total number of Borrelia infections in nymphal ticks collected during May and June 2 yr later. The presence of the same genospecies both in naturally engorged larvae and blood-positive animals as well as the high predominance of B. burgdorferi s.s. in questing nymphs strongly differs from most study sites investigated in Europe. This unique pattern of Borrelia-diversity in both rodents and ticks seems to be determined by highly site-specific host vertebrate cenosis, and yellow-necked mice are involved in the maintenance of B. burgdorferi s.s. in the forest habitat. However, the transmission efficiency of this spirochete from the mice to the I. ricinus vector seems to be very low. The research provides additional information on the complexity of B. burgdorferi s.l. ecology in Europe, pointing to the importance of the local host community.     

Infestation of sand lizards (<Emphasis Type="Italic">Lacerta agilis</Emphasis>) resident in the Northeastern Poland by <Emphasis Type="Italic">Ixodes ricinus</Emphasis> (L.) ticks and their infection with <Emphasis Type="Italic">Borrelia burgdorferi</Emphasis> sensu lato

Sand lizards (Lacerta agilis) were trapped and examined for ticks from May to September in 2002 and 2003 in Northeastern Poland. A total of 233 Ixodes ricinus (L.) ticks (76 larvae and 157 nymphs) was found on 31 of 235 captured lizards (13.2%). The tick infestation is relatively low compared to that of mammals and passerine birds from the same area (Siński et al. 2006, Gryczyńska et al. 2002). Tick infestation depended on the month of capture, being the highest in spring. In autumn no ticks were recorded on any of the captured lizards. The oldest lizards carried the highest number of ticks but no differences related to sex of the host were found. All the collected ticks were analysed by PCR for the presence of Borrelia burgdorferi sensu lato, the etiological agents of Lyme disease. Spirochetes were detected in 11 out of 233 (4.7%) ticks tested. Genetic analysis confirmed that the spirochetes are members of the Borrelia afzelii, B. garinii and B. burgdorferi sensu stricto genospecies. Mixed infection were not detected. The prevalence of infection was analysed in relation to months of the capture, age and sex of the lizards, but differences were not statistically significant. The obtained results suggest that lizards are probably not B. burgdorferi reservoirs, but further studies are required to confirm this.     

Genetic diversity of Borrelia burgdorferi sensu lato in ticks from mainland Portugal

To date Borrelia lusitaniae is the only genospecies of Borrelia burgdorferi sensu lato isolated from Ixodes ricinus ticks collected in Portugal and Tunisia. This suggests that the genospecies diversity of B. burgdorferi sensu lato decreases toward the southwestern margin of its Old World subtropical range. In order to further explore the genetic diversity of B. burgdorferi sensu lato from this region, 55 I. ricinus and 27 Hyalomma marginatum questing adults, collected during the spring of 1998 from a sylvatic habitat south of Lisbon, Portugal, were analyzed. Infection prevalences of 75% in I. ricinus ticks and 7% in H. marginatum ticks were detected by a nested PCR that targets the rrf (5S)-rrl (23S) spacer of B. burgdorferi sensu lato. Restriction fragment length polymorphism (RFLP) analysis of the I. ricinus-derived amplicons showed that the sequences in the majority of samples were similar to those of B. lusitaniae type strains (76% for strain PotiB1, 5% for strain PotiB3). Two novel RFLP patterns were obtained from 12% of the samples. The remaining 7% of samples gave mixed RFLP patterns. Phylogenetic analysis of rrf-rrl spacer sequences revealed a diverse population of B. lusitaniae in questing adult I. ricinus ticks (the sequences did not cluster with those of any other genospecies). This population consisted of 10 distinct sequence types, suggesting that multiple strains of B. lusitaniae were present in the local I. ricinus population. We hypothesize that B. lusitaniae has a narrow ecological niche that involves host species restricted to the Mediterranean Basin.     

Distribution of Borrelia burgdorferi sensu lato in Ixodes ricinus (Acari: Ixodidae) ticks from the Basque Country, Spain

Borrelia burgdorferi was found widespread in ixodid ticks from the Basque Country (Spain) during a two-step study. In the first part, a total of 7,835 ixodids of eight different species was collected from vegetation, classified, and processed using polymerase chain reaction (PCR) for detection of B. burgdorferi ospA DNA. B. burgdorferi DNA wasdetectedin < or = 12.5% of adults and > or = 0.6% of Ixodes ricinus (L., 1758) nymphs (mean 1.5 and 0.05%, respectively), and in < or = 14.3% of adult Hemaphysalis punctata (Canestrini & Fanzago, 1877) analyzed (mean 1.2%). The second part of the study was undertaken 2 yr later to characterize B. burgdorferi distribution by focusing on the areas where L. ricinus was the predominant species. Ten areas were selected from which 1,535 nymphs and adults of I. ricinus were collected and processed by PCR and culture techniques. Infected ticks were found in all zones. B. burgdorferi DNA was detected in a mean of 9.3 and 1.5% of adults and nymphs, respectively. Nine isolates of B. burgdorferi were obtained, belonging to four different genospecies (B. burgdorferi sensu stricto, B. garinii, B. valaisiana, and B. lusitaniae). The results indicate that some areas of Spain have a potential risk for Lyme disease agent exposure and that B. borgdorferi appears to have an increasing occurrence in ticks in the Basque Country.     

Borrelia burgdorferi s.l. in Ixodes ricinus (Acari: Ixodidae) ticks collected from vegetation and small rodents in recreational areas of the city of Poznań

During 1998-1999, Ixodes ricinus (L.) populations were investigated in three different biotopes (deciduous, mixed, coniferous forest) situated in popular recreational areas in Poznań, Poland. In total, 1,123 questing ticks (1,002 nymphs, 69 males, 52 females) were collected by flagging vegetation. Additionally, in 1998 between May and September small rodents were trapped and inspected for feeding ticks. Altogether, 213 rodents of three species: Apodemus agrarius Pall., A. flavicollis Melchior, Clethrionomys glareolus Schreber were captured. Of 323 engorged ticks, 304 were larvae and 19 nymphs. All ticks collected from vegetation, as well as from rodents were examined for the presence of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigenwalt & Brenner s.l. spirochetes by indirect immunofluorescence assay (IFA) using PAB 1B29. The seasonal pattern of activity of questing I. ricinus was always bimodal (May/June and August/September). The most abundant tick population occurred in the deciduous forest. The total infection rate in questing ticks was 16.2%. Differences in mean infection prevalence of host-seeking ticks between three biotopes each year were not significant. On average more larvae parasitized on the genus of Apodemus than on C. glareolus. 17.8% of larvae and 31.6% of nymphs fed on rodents harbored spirochetes. The three rodent species contributed to a different degree in to transmission of the pathogen to subadult stages. Approximately 27% of larvae infested on A. agrarius, 22% on C. glareolus, and only 4.2% on A. flavicollis contained spirochetes. The results suggest that the prevalence of A. agrarius and C. glareolus in disturbed urban forests used for leisure activities seems to be crucial for the maintenance of B. burgdorferi s.l. in I. ricinus populations.     

Ixodes ricinus density, and distribution and prevalence of Borrelia burgdorferi sensu lato infection along an altitudinal gradient

In this study, we measured the phenology of Ixodes ricinus ticks and their infection with Borrelia burgdorferi sensu lato (sl) simultaneously along an altitudinal gradient to assess the impact of climate on the phenology of ticks and on their infection with B. burgdorferi sl. From 1999 to 2001, free-living I. ricinus ticks were collected monthly by flagging vegetation at three different altitudes (620, 740, and 900 m above sea level) on the slope of a mountain in Chaumont (Neuchatel, Switzerland). I. ricinus ticks were examined for the presence of B. burgdorferi sl by using direct fluorescent antibody assay and isolation of spirochetes. Borrelia species were characterized by polymerase chain reaction followed by restriction fragment-length polymorphism. Tick density and tick phenology varied with altitude. Although the peak tick density decreased and the onset of ticks was delayed with altitude, the phenology was much more stable among years at the highest altitudes than at the lowest. The prevalence of B. burgdorferi infection in nymphs and adults decreased with altitude. The prevalence of infection differed significantly among years, and it was significantly higher in adults (30%) than in nymphs (21%). B. burgdorferi infection in adults was positively related with adult density, but this was not observed for nymphs. Five B. burgdorferi sl genospecies were successfully isolated: B. garinii, B. burgdorferi sensu stricto, B. afzelii, B. valaisiana, and B. lusitaniae. Mixed infections were obtained from five of 140 infected ticks. The greatest diversity in Borrelia species was observed at the lowest altitude where all five Borrelia species were present, whereas at the two highest altitudes, B. lusitaniae was not observed.     

PCR detection of granulocytic ehrlichiae in Ixodes ricinus ticks and wild small mammals in western Switzerland

The presence of granulocytic ehrlichiae was demonstrated by PCR in Ixodes ricinus ticks and wild small mammals in Switzerland in two areas of endemicity for bovine ehrlichiosis. Six ticks (three females and three nymphs) (1.4%) of 417 I. ricinus ticks collected by flagging vegetation contained ehrlichial DNA. A total of 201 small mammals from five species, wood mouse (Apodemus sylvaticus), yellow-necked mouse (Apodemus flavicollis), earth vole (Pitymys subterraneus), bank vole (Clethrionomys glareolus), and common shrew (Sorex araneus), were trapped. The analysis of I. ricinus ticks [corrected] collected on 116 small mammals showed that nine C. glareolus voles and two A. sylvaticus mice hosted infected tick larvae. In these rodents, granulocytic ehrlichia infection was also detected in blood, spleen, liver, and ear samples. Further examinations of 190 small mammals without ticks or with noninfected ticks showed the presence of ehrlichial DNA in spleen and other tissues from six additional C. glareolus, three A. flavicollis, and one S. araneus mammals. This study suggests that A. sylvaticus, A. flavicollis, S. araneus, and particularly C. glareolus are likely to be natural reservoirs for granulocytic ehrlichiae. Partial 16S rRNA gene sequences of granulocytic ehrlichiae from ticks and rodents showed a high degree of homology (99 to 100%) with granulocytic ehrlichiae isolated from humans. In contrast, groESL heat shock operon sequence analysis showed a strong divergence (approximately 5%) between the sequences in samples derived from rodents and those derived from samples from questing ticks or from other published ehrlichia sequences. Dual infections with granulocytic ehrlichia and Borrelia burgdorferi were found in ticks and small mammals.     

Early detection of Borrelia burgdorferi sensu lato infection in Balb/c mice by co-feeding Ixodes ricinus ticks

In Europe, Borrelia burgdorferi is transmitted by Ixodes ricinus to animals and human. When infected and uninfected ticks co-feed on a host, spirochetes are transmitted from ticks to animal and also to uninfected ticks. Here, we used uninfected ticks to co-feed with infected ticks on mice to evaluate this method to detect early infection in mice. A total of 128 mice were challenged by infected nymphs placed in capsules glued on the back of the mice. Three days later uninfected larvae were added in the capsule to co-feed with infected nymphs and were examined for Borrelia infection after natural detachment. Infection in mice was also determined by xenodiagnosis and by spirochete isolation from ear skin biopsy and back skin biopsy taken at the tick attachment site one month after infection. A total of 111 mice were found to be infected by at least one of these four methods. Borrelia infection was observed in 95% of mice by the co-feeding method, in 92% of mice by xenodiagnosis, in 69% and in 68% of mice by cultivation of ear and back skin biopsies, respectively. Our results demonstrate that the co-feeding method is a very sensitive method which can be used to detect very early infection in mice infected by tick bites.     

Diversity and coexistence of tick-borne pathogens in central Germany

In total, 1000 Ixodes ricinus L. ticks were collected from a small recreational forest area in central Germany (Thuringia) and investigated for the presence of Borrelia spp., Babesia spp., Anaplasma spp., Rickettsia spp., Coxiella burnetii, and Francisella tularensis. Overall, 43.6% of the ticks were infected with at least one pathogen. In 8.4% of ticks double infections were detected, and 1.6% harbored more than two pathogens. In this study, we present data on the coexistence of established and emerging pathogens in questing nymphs and adult ticks in a recreational area in central Germany, indicating the need for further studies for a reliable risk assessment.     

High Prevalence of Granulocytic Ehrlichiae and Borrelia burgdorferi Sensu Lato in Ixodes ricinus Ticks from Bulgaria

Bulgarian Ixodes ricinus ticks were examined for Ehrlichia and Borrelia coinfection: 34 and 32% of adult ticks and at least 2 and 10% of nymphs were positive for these infections, respectively. Coinfections and dual or triple Borrelia infections were frequent, although Ehrlichia phagocytophila heterogeneity was minimal. Multiple tick-borne bacteria coexist in I. ricinus ticks in southeastern Europe.     

Identification of Ehrlichia spp. and Borrelia burgdorferi in Ixodes ticks in the Baltic regions of Russia

The presence and distribution of Ehrlichia spp. and Borrelia burgdorferi sensu lato was demonstrated among ixodid ticks collected in the Baltic regions of Russia, where Lyme borreliosis is endemic. A total of 3,426 Ixodes ricinus and 1,267 Ixodes persulcatus specimens were collected, and dark-field microscopy showed that 265 (11.5%) I. ricinus and 333 (26.3%) I. persulcatus ticks were positive. From these samples, 472 dark-field-positive and 159 dark-field-negative ticks were subjected to PCR and subsequent reverse line blot hybridization. Fifty-four ticks (8.6%) carried Ehrlichia species, and 4 (0.6%) carried ehrlichiae belonging to the Ehrlichia phagocytophila complex, which includes the human granulocytic ehrlichiosis agent. The E. phagocytophila complex and an Ehrlichia-like species were detected only in I. ricinus whereas Ehrlichia muris was found exclusively in I. persulcatus, indicating a possible vector-specific infection. Borrelia garinii was found predominantly in I. persulcatus, but Borrelia afzelii was evenly distributed among the two tick species. Only two I. ricinus ticks carried B. burgdorferi sensu stricto, while Borrelia valaisiana and a newly identified B. afzelii-like species were found in 1.7 and 2.5% of all ticks, respectively. Of the dark-field-positive ticks, only 64.8% yielded a Borrelia PCR product, indicating that dark-field microscopy may detect organisms other than B. burgdorferi sensu lato. These observations show that the agent of human granulocytic ehrlichiosis may be present in ticks in the Baltic regions of Russia and that clinicians should be aware of this agent as a cause of febrile disease.     

Infection of Ixodes ricinus (Acari: Ixodidae) by Borrelia burgdorferi sensu lato in North Africa

Free-living adult Ixodes ricinus L, were collected in Amdoun, situated in the Kroumiry mountains in northwestern Tunisia (North Africa). Using direct fluorescence antibody assay, the infection rate of field-collected I. ricinus by Borrelia burgdorferi sensu lato was 30.5% (n = 72). No difference in infection rate was observed between male and female ticks. Spirochetes that had been isolated from I. ricinus from Ain Drahim (Kroumiry Mountains) in 1988 were identified as Borrelia lusitaniae (formerly genospecies PotiB2). This is the first identification of a genospecies of Borrelia burgdorferi sensu lato from the continent of Africa.     

Infestation with pathogen-free nymphs of the tick Ixodes scapularis induces host resistance to transmission of Borrelia burgdorferi by ticks.

Female BALB/c mice were infested four times with pathogen-free Ixodes scapularis nymphs prior to infestation with nymphs infected with Borrelia burgdorferi B31. Each infestation was separated by a 14-day tick-free period. Mean weights of fed ticks and percentage reaching repletion did not indicate development of acquired resistance. Only 16.7% of mice repeatedly infested with pathogen-free ticks prior to infected I. scapularis nymph challenge became positive for B. burgdorferi. One hundred percent of control mice infested only with infected ticks were culture positive for B. burgdorferi.     

Lyme disease in California: interrelationship of Ixodes pacificus (Acari: Ixodidae), the western fence lizard (Sceloporus occidentalis), and Borrelia burgdorferi

The relationship of immature western black-legged ticks, Ixodes pacificus Cooley and Kohls, to the western fence lizard, Sceloporus occidentalis Baird and Girard, and to the Lyme disease spirochete, Borrelia burgdorferi, was investigated in chaparral and woodland-grass habitats in northern California from 1984 to 1986. Immature ticks were found on lizards in spring and summer, but the prevalence and abundance of ticks on this host were considerably greater in spring. The peak of larval abundance preceded that of nymphs by several weeks, but there was considerable seasonal overlap between these parasitic stages. Larvae and nymphs attached primarily to the lateral nuchal pockets of lizards in chaparral (99.5%) and woodland-grass (91.8%). The numbers of larvae infesting lizards in spring fit the negative binomial distribution in woodland-grass but not in chaparral; insufficient data precluded similar analyses for nymphs. Tick loads did not differ significantly with respect to age or gender of the lizard. Spirochetal infection rates (range, 0-3.7%) in I. pacificus immatures were comparable in both habitats and were similar to those reported previously for adults of this tick. Overall, 1 (0.9%) of 117 larvae and 10 (1.8%) of 552 nymphs were infected with spirochetes resembling B. burgdorferi. Spirochetes were not observed in blood smears prepared from 261 wild-caught lizards, including five lizards fed upon by infected ticks at the time of collection. These and other findings suggest that S. occidentalis, although an important host of I. pacificus immatures, may be less important as a source for infecting ticks with B. burgdorferi.     

Detection and identification of Anaplasma phagocytophilum, Borrelia burgdorferi, and Rickettsia helvetica in Danish Ixodes ricinus ticks

Borreliosis is an endemic infection in Denmark. Recent serosurveys have indicated that human anaplasmosis may be equally common. The aim of this study was to look for Anaplasma phagocytophilum and related pathogens in Ixodes ricinus ticks and estimate their prevalence, compared to Borrelia, using PCR. Ticks were collected from three locations in Denmark: Jutland, Funen, and Bornholm. Ticks from Jutland and Funen were analysed individually, ticks from Bornholm were analysed in pools of 20. A. phagocytophilum was found in ticks from all areas. A. phagocytophilum was found in 23.6% of ticks from Jutland and Funen, while 11% were positive for Borrelia burgdorferi. The Borrelia genotype B. afzelii was most prevalent, followed by B. valaisiana, B. burgdorferi s.s. and B. garinii.A. phagocytophilum was found in 14.5% of nymphs and 40.5% of adult ticks, while Borrelia was found in 13% of nymphs and 8% of adult ticks. The difference in prevalence between Anaplasma and Borrelia in adult ticks supports the idea that their maintenance cycles in nature may be different. Ticks were also infected with Rickettsia helvetica. Our study indicates that A. phagocytophilum prevalence in ticks in Denmark is as high as Borrelia prevalence and that human anaplasmosis may be unrecognized.     

The role of the sand lizard (Lacerta agilis) in the transmission cycle of Borrelia burgdorferi sensu lato

In order to examine the role of Lacerta agilis in the transmission cycle of Borrelia burgdorferi sensu lato, lizards were captured in three different localities in Slovakia, Poland, and Romania. Skin biopsy specimens from collar scales and ticks feeding on the lizards at the time of capture were collected. In total, 87 individuals (11 in Slovakia, 48 in Poland, 28 in Romania) of L. agilis were captured. Altogether, 245 (74, 74, 97) larvae and 191 (78, 113, 0) nymphs were removed from captured lizards. Borrelial infection was detected by PCR amplifying a fragment of the 5S–23S rDNA intergenic spacer and genotyping by restriction fragment length polymorphism (RFLP). When examining the presence of borreliae in biopsy specimens, striking differences between separate populations were observed. Whilst none of the biopsy specimens from L. agilis from Poland were positive for B. burgdorferi s.l., 45% of the sand lizards from Slovakia and 57% from Romania were positive. B. lusitaniae was confirmed in all positive biopsy specimens. The prevalence of borreliae in ticks that had fed on lizards was 6% in Poland, 21% in Slovakia, and 13% in Romania. While B. lusitaniae was the only genospecies in ticks from Slovakia (except for 2 larvae infected with B. afzelii) and Romania, it represented 64% and B. valaisiana 27% of the borrelia infections in ticks from lizards captured in Poland. The highest probability of ticks to get infected expressed as specific infectivity of lizards was recorded in Slovakia (0.102) and the lowest in Poland (0.003). Our findings underline the importance of the sand lizard in the transmission cycle of B. lusitaniae.     

Apodemus species mice are reservoir hosts of Borrelia garinii OspA serotype 4 in Switzerland

Among Borrelia burgdorferi sensu lato isolates, seven outer surface protein A (OspA) serotypes have been described: serotypes 1 and 2 correspond to B. burgdorferi sensu stricto and Borrelia afzelii, respectively, and serotypes 3 to 7 correspond to Borrelia garinii. In Europe, serotype 4 has never been isolated from Ixodes ricinus ticks until recently, although this serotype has been frequently isolated from cerebrospinal fluid from patients. In Europe, B. afzelii and B. burgdorferi sensu stricto were found associated with rodents and B. garinii was found associated with birds. In this study, the reservoir role of Apodemus mice for B. garinii OspA serotype 4 was demonstrated by xenodiagnosis. Apodemus mice are the first identified reservoir hosts for B. garinii OspA serotype 4.