Seropositivity of Borrelia burgdorferi in a cohort of symptomatic cats from Europe based on a C6-peptide assay with discussion of implications in disease aetiology.

There are only few reports on Lyme borreliosis (LB) in cats. The reasons might be a different tick infestation in cats compared to dogs, a low susceptibility for tick-borne infections or a low awareness of veterinarians for tick-borne diseases in feline patients. The aim of this study was to determine the proportion of antibodies against Borrelia burgdorferi sensu lato (Bbsl) in feline sera, to compare the significance of feline versus canine LB, as well as to evaluate possible implications on disease occurrence. Specific antibodies against the C6-peptide of Bbsl in cats were detected by a rapid test based on enzyme immunoassay technique. The serum samples were sent to a diagnostic laboratory by veterinarians from Germany and other European countries with request for Borrelia serology in the years 2009-2011. Veterinarians were asked for information regarding the cats' location, age, gender, clinical signs, treatment and follow-up. In six of 271 (2.2%; 95% CI: 0.8-4.8%) cat sera, antibodies against the C6-peptide of Bbsl were detected. Proportion of Borrelia antibody-positive cat sera was significantly lower than the one determined for dogs during the same time period. All positive cats lived in countries endemic for LB (Germany, Sweden and Belgium), and all C6-antibody positive cats with the exception of one cat showed clinical signs. Possible implications on disease occurrence are discussed. Data presented here demonstrate a lower prevalence of Borrelia specific C6-antibodies in European cats when compared to dogs residing in the same regions. The absence of antibodies against Bbsl in 97.8% (95% CI: 95.2-99.2%) of the submitted samples indicate that diagnosis "feline LB"is rare in cats. Nevertheless, LB should be considered in cats with compatible clinical signs (e.g. shifting leg lameness, to less extent neurological signs) when other differential diagnoses are ruled out.

Tick-borne Diseases (Borreliosis, Anaplasmosis, Babesiosis) in German and Austrian Dogs: Status quo and Review of Distribution, Transmission, Clinical Findings, Diagnostics and Prophylaxis.

Tick-borne diseases (TBD) in dogs have gained in significance in German and Austrian veterinary practices. The widespread European tick species Ixodes ricinus represents an important vector for spirochaetes of the Borrelia burgdorferi sensu lato group and Rickettsiales such as Anaplasma phagocytophilum. The meadow or ornate dog tick (Dermacentor reticulatus) is an important vector for Babesia canis, as is the brown dog tick (Rhipicephalus sanguineus) for Babesia vogeli in the Mediterranean region. The present work covers pathogen transmission by tick vectors, including the mechanisms and the minimum intervals required, in conjunction with possible non-vector-borne transmission routes. It also addresses the incubation periods, pathogenicity and clinical findings associated with each pathogen and genospecies and presents case examples. Current data on prevalence, annual fluctuations and distribution in various pre-selected dog populations (symptomatic versus asymptomatic) in both countries are depicted in maps. Reasons for changes in prevalence (especially of Borrelia) are discussed. Criteria and algorithms for clinical diagnosis and monitoring in dogs, including case history, direct detection (blood smears, molecular detection by species-specific PCR and sequencing) and indirect methods (whole-cell and peptide-based antibody tests), are presented, together with laboratory abnormalities (haematology, clinical chemistry, urine). The role of anti-C6 antibody concentration (ACAC) and its correlation with proteinuria and Lyme nephritis are assessed on the basis of new data. Consideration is also given to the importance of blood smears, PCR and serology in the case of anaplasmosis and babesiosis, and the diagnostic value of combining these methods. The relevance of molecular differentiation of Anaplasma species (A. phagocytophilum versus A. platys) and Babesia spp. (large versus small forms) in cases of serological cross-reaction is emphasized. A summary is given of methods for prophylaxis using acaricide products (collars, spot-on solutions and oral treatments in both countries), vaccination (Borrelia and Babesia vaccines) and imidocarb-based chemoprophylaxis for large Babesia.

Presence of an emerging subclone of Francisella tularensis holarctica in Ixodes ricinus ticks from south-western Germany.

The zoonotic disease tularaemia is caused by the bacterial pathogen Francisella tularensis. Although the causative agent is known for 100 years, knowledge of its enzootic cycles is still rudimentary. Apart from tabanids and mosquitoes, hard ticks have been described as important vectors and potential reservoirs for F. tularensis. Available data on the incidence of human tularaemia indicate an increase in cases in the federal state of Baden-Wuerttemberg. To determine whether ticks are involved in the reported increase in F. tularensis infections in humans and wildlife in this south-western part of Germany, 916 Ixodes ricinus and 211 adult Dermacentor marginatus and D. reticulatus ticks were collected in two different locations. Screening for the presence of F. tularensis was performed by real-time PCR of the 16S rRNA gene. Of the 95 pools of I. ricinus ticks (representing 916 individual ticks), 8 tick pools (8.4%) were positive in this PCR. 30-bp deletion PCR confirmed that the F. tularensis subspecies holarctica was present. FtM24 VNTR analysis revealed that they belong to the emerging Franco-Iberian subclone group of F. tularensis holarctica. Of the 211 ticks of the genus Dermacentor, 35 randomly chosen DNAs were subjected to 16S rRNA gene screening PCR; 20 of these (57%) gave positive signals. For cluster analysis, the lpnA gene region of all Francisella-positive I. ricinus pools and 6 Dermacentor ticks with a positive reaction in the screening PCR was amplified and sequenced. In the resulting neighbour-joining tree, all Francisella-positive I. ricinus samples clustered with sequences of F. tularensis, whilst all Dermacentor tick samples clustered with FLE (Francisella-like endosymbiont) sequences. This study shows that I. ricinus ticks may serve as vectors and/or reservoirs of F. tularensis in Germany and supports the hypothesis that the state of Baden-Wuerttemberg represents an emerging endemic focus of tularaemia.

Prevalence of Coxiella burnetii and Rickettsia spp. in ticks and rodents in southern Germany.

Coxiella burnetii, the causative agent of Q fever, and Rickettsia spp. are bacterial pathogens that can be transmitted by ticks of the genus Dermacentor (i.e., Dermacentor marginatus and D. reticulatus). In Germany, the occurrence of these ticks is currently limited to few areas. However, due to increasing temperatures, these vectors will likely extend their distribution in the future, and C. burnetii and Rickettsia spp. might spread with them. To assess the prospective risk of human infections by these agents, it is important to know their current distribution. We collected 666 adult Dermacentor spp. and 119 rodents, mainly Microtus arvalis, in 3 Q fever endemic areas in southern Germany. Ticks and rodent organ pools were screened by PCR for C. burnetii and Rickettsia spp. No evidence of C. burnetii infections could be found in ticks or rodents, suggesting that these animals do not play an essential role in the epidemiology of Q fever in Germany. Rickettsia raoultii and R. slovaca could be detected in 30.3% and 0.75% of all examined ticks, respectively. In contrast, no rickettsia infections could be found in any rodent samples. Both rickettsia species can cause tick-borne lymphadenopathy (TIBOLA), a usually mild human disease. Because of the possible transmission of these rickettsiae to humans, TIBOLA should be considered in the differential diagnosis of tick-borne diseases. Our data show that a spread of these rickettsiae is possible in Germany and that more studies on the distribution of these agents are necessary.

Spread of ticks and tick-borne diseases in Germany due to global warming.

Tick-transmitted diseases like tick-borne encephalitis and Lyme Borreliosis have been well known in Germany for decades. Global climate changes may influence the emergence and reemergence of diseases. Ongoing research now gives an additional focus on other tick-borne pathogens such as Coxiella burnetii, Rickettsia conorii, Anaplasma phagocytophilum and Babesia spp., the causative agents of Q-fever, Mediterranean spotted fever, Anaplasmosis and Babesiosis, respectively. The epidemiology of these pathogens was investigated on ticks as well as on rodents, the main hosts. Therefore adults of Dermacentor spp. (n = 862) and rodents (n = 119) were collected and examined for the existence of C. burnetii and Rickettsia spp. by polymerase chain reaction (PCR). In none of the ticks and rodents C. burnetii could be detected, in contrast to Rickettsia spp. where the infection rate in ticks was about 20%. Over and above that, nymphs and adults of Ixodes ricinus were also collected and investigated by PCR for A. phagocytophilum (n = 5,424), Rickettsia helvetica (n = 1,187) and Babesia spp. (n = 3,113). Thereby infection rates of 1%, 8.9% and 1%, respectively, could be determined. The prevalence in rodents was 5.3% for A. phagocytophilum and 0.8% for Babesia microti. None of the rodents was R. helvetica positive.