[Prevalence of antibodies against Tick-Borne Encephalitis virus in dogs from Saxony, Germany]. / Zum Vorkommen von Antikörpern gegen das Frühsommer-Meningoenzephalitis- Virus bei Hunden in Freistaat Sachsen, Deutschland.

Tick-borne encephalitis (TBE) is the most important tick-transmitted viral disease in Europe and is caused by the TBE virus (TBEV), a member of the Flaviviridae family. In Germany, the vast majority of human TBE cases occurs in the south in so-called risk areas. However, in areas with only sporadic TBE cases, the respective risk assessment is hard to achieve. We therefore intend to use the prevalence of antibodies against TBEV in dogs as an indicator to trace such TBE endemic areas. Between August 2012 and March 2014, a total of 331 blood sera were collected from dogs all over Saxony, which hadn't left the state for the past five years. For the detection of antibodies against TBE-virus a commercial ELISA was used. Ten sera with positive or borderline ELISA results were retested by serum neutralization test. All seven ELISA-positive serum samples could be verified to contain TBE-virus-specific antibodieswith SNT titres between 1:15 and more than 1:40. We therefore found 2.1% seroprevalence in our samples. We conclude, that dogs can very well be used as sentinels, especially in areas with only sporadic TBE cases, although larger sample sizes are desired.

Seroprevalence of spotted fever group Rickettsiae in dogs in Germany.

Tick-transmitted spotted fever group Rickettsiae (SFGR) are considered emerging disease pathogens in Europe. To assess the situation in Germany, a seroepidemiologic survey of dogs (n=605, which have never left Germany) was conducted to determine the prevalence of antibodies to SFGR. For this purpose, a commercially available enzyme-linked immunosorbent assay (ELISA) test for all SFGR was used. A total of 78% of the dogs were positive for antibodies of the SFGR, and there was a positive correlation between age, tick-infestation, and seropositivity. There was no correlation between clinical state, location, and seropositivity, suggesting that infection with rickettsia is neither related to the health condition of the dogs nor to their abode in Germany. According to our results, all of Germany can be considered as an endemic area for SFGR. This should be taken into account when assessing the epidemiology of human rickettsioses and their impact on public health.

Candidatus Neoehrlichia mikurensis and Anaplasma phagocytophilum: prevalences and investigations on a new transmission path in small mammals and ixodid ticks.

BACKGROUND: Small mammals are crucial for the life history of ixodid ticks, but their role and importance in the transmission cycle of tick-borne pathogens is mostly unknown. Candidatus Neoehrlichia mikurensis (CNM) and Anaplasma phagocytophilum are both tick-borne pathogens, and rodents are discussed to serve as main reservoir hosts for CNM but not for the latter especially in Germany. Analysing the prevalence of both pathogens in small mammals and their ticks in endemic regions may help to elucidate possible transmission paths in small mammal populations and between small mammals and ticks. METHODS: In 2012 and 2013, small mammals were trapped at three different sites in Germany. DNA was extracted from different small mammal tissues, from rodent neonates, foetuses and from questing and attached ticks. DNA samples were tested for CNM and A. phagocytophilum by real-time PCR. Samples positive for A. phagocytophilum were further characterized at the 16S rRNA gene locus. RESULTS: CNM was detected in 28.6% of small mammals and in 2.2% of questing and 3.8% of attached ticks. Altogether 33 positive ticks were attached to 17 different hosts, while positive ticks per host ranged between one and seven. The prevalences for this pathogen differed significantly within small mammal populations comparing sites (χ(2): 13.3987; p: 0.0004) and between sexes. Male rodents had an approximately two times higher chance of infection than females (OR: 1.9652; 95% CI: 1.32-2.92). The prevalence for CNM was 31.8% (95% CI: 22-44) in rodent foetuses and neonates (23 of 67) from positive dams, and 60% (95% CI: 35.7-80.25) of positive gravid or recently parturient rodents (9 out of 15) had at least one positive foetus or neonate. Anaplasma phagocytophilum was detected at a low percentage in rodents (0-5.6%) and host-attached ticks (0.5-2.9%) with no significant differences between rodent species. However, attached nymphs were significantly more often infected than attached larvae (χ(2): 25.091; p: <0.0001). CONCLUSION: This study suggests that CNM is mainly a rodent-associated pathogen and provides evidence for a potential transplacental transmission in rodents. In contrast, most of the rodent species captured likely represent only accidental hosts for A. phagocytophilum at the investigated sites.

Prevalence of antibodies against tick-borne encephalitis virus in wild game from Saxony, Germany.

Tick-borne encephalitis (TBE) is the most important tick-transmitted viral disease in Europe and is caused by the flavivirus TBE-virus (TBEV). In Germany TBE is unevenly distributed with the vast majority of cases occurring in the south in so-called risk areas defined as regions with an incidence of at least 1 case in 100,000 inhabitants. However, in low endemic areas with lesser TBE cases the respective risk assessment is hard to achieve. We therefore intend to use the prevalence of antibodies against TBEV in wildlife to trace TBEV endemic areas as a surrogate marker for the notification of human cases. This study was conducted in Saxony, Germany, where 34 autochthonous cases were reported since 2001, thereby not allowing a geographic allocation within the state. A total of 1,851 sera from wild boar and 35 sera from roe deer from all Saxon districts shot between April 2011 and March 2013 were screened for the presence of antibodies against TBEV. The overall seropositivity for Saxony was 10.5%. Among the wild boar sera, most positive samples could be found in the districts Meißen (23%) and Vogtlandkreis (20%) followed by Dresden (18%), Erzgebirgskreis and Görlitz (both 10%). We conclude that seroprevalence studies in game animals represent a promising surrogate marker and should be considered for future determination of risk areas. Although we are currently unable to explain the discrepancy of the few human cases and the high seroprevalence in some districts, vaccination against TBE should be considered for people planning outdoor activities in Dresden, Meißen or Vogtlandkreis.