Borrelia in granuloma annulare, morphea and lichen sclerosus: a PCR-based study and review of the literature

Morphea, granuloma annulare (GA) and lichen sclerosus et atrophicans (LSA) have also been suggested to be linked to Borrelia infection. Previous studies based on serologic data or detection of Borrelia by immunohistochemistry and polymerase chain reaction (PCR) reported contradictory results. Thus, we examined skin biopsies of morphea, GA and LSA by PCR to assess the prevalence of Borrelia DNA in an endemic area and to compare our results with data in the literature.

Swiss Army Survey in Switzerland to determine the prevalence of Francisella tularensis, members of the Ehrlichia phagocytophila genogroup, Borrelia burgdorferi sensu lato, and tick-borne encephalitis virus in ticks

A total of 6071 Ixodes ricinus ticks were collected on Swiss Army training grounds in five regions of Switzerland. The aim of the survey was to assess the prevalence of ticks infected with the human pathogens Francisella tularensis, members of the Ehrlichia phagocytophila genogroup, Borrelia burgdorferi sensu lato, and the European tick-borne encephalitis virus. TaqMan PCR (PE Biosystems, USA) and TaqMan RT-PCR (PE Biosystems) analyses were performed on DNA and RNA extracted from pools of ten ticks grouped by gender. Here, for the first time, it is shown that ticks may harbor Francisella tularensis in Switzerland, at a rate of 0.12%. Furthermore, 26.54% of the ticks investigated harbored Borrelia burgdorferi sensu lato, 1.18% harbored members of the Ehrlichia phagocytophila genogroup, and 0.32% harbored the European tick-borne encephalitis virus. A new instrumentation was applied in this study to carry out and analyze more than 2300 PCR reactions in only 5 days. Furthermore, the results reveal that people working in outdoor areas, including army personnel on certain training grounds contaminated with ticks containing tick-borne pathogens, are at risk for different tick-borne diseases.

Presence of potentially pathogenic Babesia sp. for human in Ixodes ricinus in Switzerland

We have designed and performed a new PCR method based on the 18S rRNA in order to individuate the presence and the identity of Babesia parasites. Out of 1159 Ixodes ricinus (Acari: Ixodidae) ticks collected in four areas of Switzerland, nine were found to contain Babesia DNA. Sequencing of the short amplicon obtained (411-452 bp) allowed the identification of three human pathogenic species: Babesia microti, B. divergens, for the first time in Switzerland, Babesia sp. EU1. We also report coinfections with B. sp. EU1-Borrelia burgdorferi sensu stricto and Babesia sp. EU1-B. afzelii.

Longterm survey (7 years) in a population at risk for Lyme borreliosis: what happens to the seropositive individuals?

In 1986, a 26% seroprevalence of IgG- anti-Borrelia burgdorferi antibodies was observed among 950 orienteers and the incidence of new clinical infections was 0.8%. In 1993, a total of 305 seropositive orienteers were reexamined. During that time, 15 cases (4.9%) of definite/probable Lyme disease occurred in this seropositive group (12 skin manifestations and 3 monoarticular joint manifestations). Among the 12 definite cases, 9 showed new clinical infections (7 EM, 1 acrodermatitis chronica atrophicans, 1 arthritis), and 3 were recurrent (2 EM, 1 arthritis). The annual incidence (0.8%) in this seropositive group was identical to the incidence observed among the whole population in 1986. The individual antibody titer decreased slightly but the seroreversion rate was low (7%). Serology was not very helpful in identifying clinical cases and evolutions, and it can be stated, that a positive serology is much more frequent in this risk group than clinical disease.

[Prevalence of Lyme borreliosis in a Swiss population at risk]

The epidemiology of "Lyme borreliosis" in Europe and the significance of positive antibody titers against Borrelia burgdorferi is not well known. Since "orienteering", a competitive cross country sport with a map and a compass, usually in forests, elevates the risk of being bitten by ticks and infected by B. burgdorferi, nearly 1000 orienteerers were included in a prospective study. - In this population the prevalence of positive IgG-antibodies (immunofluorescence technique) was almost 20% and of IgM-antibodies 4%. However, the frequency of associated symptoms in the clinical history of the probands was very low, even in individuals with highly positive titers. - We conclude that the rate of asymptomatic Borrelia infections is high in this special group, and probably also in the general population, and that one has therefore to be cautious in interpreting an isolated positive "Lyme titer". Further investigations are needed, and, in particular, follow-up of the many "positive" subjects without clinical symptoms may be helpful in understanding this fascinating disease better.

Third degree atrioventricular block and accelerated idioventricular rhythm associated with a heart base chemodectoma in a syncopal Rottweiler.

A 7-year-old male intact Rottweiler was presented with a 1-week history of lethargy, anorexia, vomiting and multiple syncopal events. The results of the clinical examination and electrocardiography were consistent with a third degree atrioventricular block and an intermittent accelerated idioventricular rhythm. Haematology, serum biochemistry, serology for Borrelia burgdorferi, blood culture, total T4, thoracic radiography and echocardiography did not reveal the cause of the arrhythmia. Response to medical treatment with isoproterenol was poor. Pacemaker placement was declined by the owners and the dog was euthanized at their request. Histopathological examination of the heart revealed a chemodectoma at the base of the heart. There was no neoplastic infiltration of the conduction tissue. Potential mechanisms explaining the association of the arrhythmias and the tumour, such as vagal stimulation and neuroendocrine factors are discussed.

Survey of selected tick-borne diseases in dogs in Finland

BACKGROUND: Due to climate changes during the last decades, ticks have progressively spread into higher latitudes in northern Europe. Although some tick borne diseases are known to be endemic in Finland, to date there is limited information with regard to the prevalence of these infections in companion animals. We determined the antibody and DNA prevalence of the following organisms in randomly selected client-owned and clinically healthy hunting dogs living in Finland: Ehrlichia canis (Ec), Anaplasma phagocytophilum (Ap), Borrelia burgdorferi (Bb) and Bartonella. METHODS: Anti-Ap, -Bb and -Ec antibodies were determined in 340 Finnish pet dogs and 50 healthy hunting dogs using the 4DX Snap(R)Test (IDEXX Laboratories). In addition, PCRs for the detection of Ap and Bartonella DNA were performed. Univariate and multivariate logistic regression analyses were used to identify risk factors associated with seropositivity to a vector borne agent. RESULTS: The overall seroprevalence was highest for Ap (5.3%), followed by Bb (2.9%), and Ec (0.3%). Seropositivities to Ap and Bb were significantly higher in the Aland Islands (p <0.001), with prevalence of Ap and Bb antibodies of 45 and 20%, respectively. In healthy hunting dogs, seropositivity rates of 4% (2/50) and 2% (1/50) were recorded for Ap and Bb, respectively. One client-owned dog and one hunting dog, both healthy, were infected with Ap as determined by PCR, while being seronegative. For Bartonella spp., none of the dogs tested was positive by PCR. CONCLUSIONS: This study represents the first data of seroprevalence to tick borne diseases in the Finnish dog population. Our results indicate that dogs in Finland are exposed to vector borne diseases, with Ap being the most seroprevalent of the diseases tested, followed by Bb. Almost 50% of dogs living in Aland Islands were Ap seropositive. This finding suggests the possibility of a high incidence of Ap infection in humans in this region. Knowing the distribution of seroprevalence in dogs may help predict the pattern of a tick borne disease and may aid in diagnostic and prevention efforts.

Multiple infections of rodents with zoonotic pathogens in Austria

Rodents are important reservoirs for a large number of zoonotic pathogens. We examined the occurrence of 11 viral, bacterial, and parasitic agents in rodent populations in Austria, including three different hantaviruses, lymphocytic choriomeningitis virus, orthopox virus, Leptospira spp., Borrelia spp., Rickettsia spp., Bartonella spp., Coxiella burnetii, and Toxoplasma gondii. In 2008, 110 rodents of four species (40 Clethrionomys glareolus, 29 Apodemus flavicollis, 26 Apodemus sylvaticus, and 15 Microtus arvalis) were trapped at two rural sites in Lower Austria. Chest cavity fluid and samples of lung, spleen, kidney, liver, brain, and ear pinna skin were collected. We screened selected tissue samples for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, Leptospira, Borrelia, Rickettsia, Bartonella spp., C. burnetii, and T. gondii by RT-PCR/PCR and detected nucleic acids of Tula hantavirus, Leptospira spp., Borrelia afzelii, Rickettsia spp., and different Bartonella species. Serological investigations were performed for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, and Rickettsia spp. Here, Dobrava-Belgrade hantavirus-, Tula hantavirus-, lymphocytic choriomeningitis virus-, orthopox virus-, and rickettsia-specific antibodies were demonstrated. Puumala hantavirus, C. burnetii, and T. gondii were neither detected by RT-PCR/PCR nor by serological methods. In addition, multiple infections with up to three pathogens were shown in nine animals of three rodent species from different trapping sites. In conclusion, these results show that rodents in Austria may host multiple zoonotic pathogens. Our observation raises important questions regarding the interactions of different pathogens in the host, the countermeasures of the host's immune system, the impact of the host–pathogen interaction on the fitness of the host, and the spread of infectious agents among wild rodents and from those to other animals or humans.