Associations between coinfection prevalence of Borrelia lusitaniae, Anaplasma sp., and Rickettsia sp. in hard ticks feeding on reptile hosts

An increasing number of studies reveal that ticks and their hosts are infected with multiple pathogens, suggesting that coinfection might be frequent for both vectors and wild reservoir hosts. Whereas the examination of associations between coinfecting pathogen agents in natural host-vector-pathogen systems is a prerequisite for a better understanding of disease maintenance and transmission, the associations between pathogens within vectors or hosts are seldom explicitly examined. We examined the prevalence of pathogen agents and the patterns of associations between them under natural conditions, using a previously unexamined host-vector-pathogen system--green lizards Lacerta viridis, hard ticks Ixodes ricinus, and Borrelia, Anaplasma, and Rickettsia pathogens. We found that immature ticks infesting a temperate lizard species in Central Europe were infected with multiple pathogens. Considering I. ricinus nymphs and larvae, the prevalence of Anaplasma, Borrelia, and Rickettsia was 13.1% and 8.7%, 12.8% and 1.3%, and 4.5% and 2.7%, respectively. The patterns of pathogen prevalence and observed coinfection rates suggest that the risk of tick infection with one pathogen is not independent of other pathogens. Our results indicate that Anaplasma can play a role in suppressing the transmission of Borrelia to tick vectors. Overall, however, positive effects of Borrelia on Anaplasma seem to prevail as judged by higher-than-expected Borrelia-Anaplasma coinfection rates.

Co-infection with Borrelia species and other tick-borne pathogens in humans: two cases from Poland

Co-infection with Borrelia species and Anaplasma phagocytophilum or Babesia spp. was assessed in a retrospective study of tick-exposed individuals from southeastern Poland. The co-infection rate of these pathogens was found to be rather low (Borrelia spp./Anaplasma phagocytophilum--4.2%, 1/24; Borrelia spp./Babesia spp.--4.2%, 1/24). However, due to the increased prevalence of Borrelia spp. in Ixodes ricinus ticks in Poland and the recent emergence of new tick-borne infections, it is necessary to carefully evaluate the true risk of human infection with several pathogens using more sensitive and reliable diagnostic tools. This is the first report of human infection with Babesia spp. in Poland that has been confirmed by molecular techniques with homology of 98.9% to B. divergens or Babesia EU1.

Evidence of Babesia microti infection in multi-infected Ixodes persulcatus ticks in Russia

To detect Babesia-infected Ixodes persulcatus Shulze in a suburb of St. Petersburg, Russia, 738 adult ticks were studied using Babesia specific primers and PCR techniques. The entire sample (more than 1,200 individuals) was screened for the presence of Borrelia spp., Ehrlichia spp. and tick-borne encephalitis virus (TBEV). All 7 ticks infected with Babesia microti, were also infected with other pathogens (all 7 among 417 infected ticks, zero amongst the remaining 321 naive ones (chi2 = 5.25, p<0.05). Babesia microti occurred twice with Borrelia afzelii, 3 times with Borrelia garinii, once with both, and once with both B. garinii and TBEV. The prevalence of infection with Borrelia spp. was 34.0%, with Ehrlichia spp. 6.2%, with TBEV 1.5%, and with Ba. microti 0.9%. Babesia microti infection was not found in combination with Ehrlichia sp. or Borrelia burgdorferi sensu stricto. The latter pathogen (prevalence 2.6%), just like Ba. microti, was not encountered as a monoinfection. The data suggest that Ba. microti infection can only survive in I. persulcatus in combination with Borrelia spp. (7 of 7 infections). The disease in humans is more severe and longer-lasting when more than one pathogen is involved. Our observations show that the well known St. Petersburg focus of tick-borne encephalitis and Lyme disease is also a focus of ehrlichiosis and babesiosis.

Borrelia burgdorferi central nervous system infection presenting as an organic schizophrenialike disorder

BACKGROUND

We report on a 42-year-old female patient who presented with a schizophreniform disorder and complete relief of symptoms after specific therapy.

METHODS

Cerebrospinal fluid and magnetic resonance imaging findings led to the diagnosis of Lyme disease.

RESULTS

To our knowledge this is the first reported case with an exclusive psychiatric manifestation of Lyme disease.

CONCLUSIONS

In case of first manifestation of psychotic disorder, although neurological symptoms are lacking, Lyme disease should be considered and be excluded by cerebrospinal fluid analysis.

[Shrews as a Borrelia reservoir in northwestern Russia]

The borreliemia was discovered in 22 (44.9%) of 49 common shrews (Sorex araneus, Soricidae), which were captured in the end of July-August 1995 in the Novgorod Province. The borreliae were located near the capillaries of the true skin and in the veins of the subcutaneous layer.

[The isolation of Borrelia from the tick Ixodes trianguliceps (Ixodidae) and the possible significance of this species in the epizootiology of ixodid tick-borne borrelioses]

Ixodes trianguliceps is a common tick species of the Eurasian forest zone. These ticks live probably in natural foci of ixodid tick-borne borrelioses (ITBB) from Western Europe to Transbaikalia, but their role in circulation of corresponding pathogens remains unclear. This study was performed in a natural ITBB focus located in the Perm region of Russia (near the Urals), where Borrelia garinii and B. afzelii circulate and I. persulcatus serves as their main vector. In July-August of 1994, 296 small mammals (mostly Clethrionomys glareolus) were tested for tick infestation. From these mammals, 49 I. trianguliceps and 252 I. persulcatus ticks were collected (16.3 and 83.7%, respectively). I. trianguliceps ticks were found on 33 rodents of three species: Cl. glareolus, Cl. rutilus, and Microtus oeconomus. The abundance of I. trianguliceps (on average, less than 0.2 ticks per animal) was approximately five times lower than that of I. persulcatus. I. trianguliceps larvae, nymphs, and adults (22, 15, and 5 specimens, respectively) were analyzed for Borrelia infection by plating their internal organs on the BSK-2 medium. Spirochete isolates were obtained from four nymphs. Three infected nymphs were collected from different Cl. glareolus specimens, and one was found on Cl. rutilus. According to the results of RFLP analysis, all four isolates were classified as B. garinii. This experiment is the first successful attempt to isolate one of ITBB pathogens from I. trianguliceps ticks. These ticks do not attack people, and their role in ITBB foci should be analyzed only in terms of epizootiology. The results of previous zoological-parasitological and bacteriological studies performed in the Ural region suggest that I. trianguliceps and I. persulcatus populations are maintained there by the same species of small rodents and insectivores, which mostly belong to the genera. Clethrionomys and Sorex. Many of them were identified as the reservoir hosts of Borrelia. These data, in complex with the fact of B. garinii isolation from I. trianguliceps, suggest that I. trianguliceps ticks are involved in the maintenance of Borrelia circulation in natural ITBB foci. Taking into account the low abundance of these ticks in the Ural forests, they should be regarded as an important but not principal component of the epizootic process. It is suggested that such a conclusion about the significance of I. trianguliceps ticks also pertains to ITBB foci of other regions.