Marc Wirtgen

Epizootic spread of Schmallenberg virus among wild cervids, Belgium, Fall 2011.

Schmallenberg virus was detected in cattle and sheep in northwestern Europe in 2011. To determine whether wild ruminants are also susceptible, we measured antibody seroprevalence in cervids (roe deer and red deer) in Belgium in 2010 and 2011. Findings indicated rapid spread among these deer since virus emergence ≈250 km away.

Spatial disaggregation of tick occurrence and ecology at a local scale as a preliminary step for spatial surveillance of tick-borne diseases: general framework and health implications in Belgium

BackgroundThe incidence of tick-borne diseases is increasing in Europe. Sub national information on tick distribution, ecology and vector status is often lacking. However, precise location of infection risk can lead to better targeted prevention measures, surveillance and control.MethodsIn this context, the current paper compiled geolocated tick occurrences in Belgium, a country where tick-borne disease has received little attention, in order to highlight the potential value of spatial approaches and draw some recommendations for future research priorities.ResultsMapping of 89,289 ticks over 654 sites revealed that ticks such as Ixodes ricinus and Ixodes hexagonus are largely present while Dermacentor reticulatus has a patchy distribution. Suspected hot spots of tick diversity might favor pathogen exchanges and suspected hot spots of I. ricinus abundance might increase human-vector contact locally. This underlines the necessity to map pathogens and ticks in detail. While I. ricinus is the main vector, I. hexagonus is a vector and reservoir of Borrelia burgdorferi s.l., which is active the whole year and is also found in urban settings. This and other nidiculous species bite humans less frequently, but seem to harbour pathogens. Their role in maintaining a pathogenic cycle within the wildlife merits investigation as they might facilitate transmission to humans if co-occurring with I. ricinus. Many micro-organisms are found abroad in tick species present in Belgium. Most have not been recorded locally but have not been searched for. Some are transmitted directly at the time of the bite, suggesting promotion of tick avoidance additionally to tick removal.ConclusionThis countrywide approach to tick-borne diseases has helped delineate recommendations for future research priorities necessary to design public health policies aimed at spatially integrating the major components of the ecological cycle of tick-borne diseases. A systematic survey of tick species and associated pathogens is called for in Europe, as well as better characterisation of species interaction in the ecology of tick-borne diseases, those being all tick species, pathogens, hosts and other species which might play a role in tick-borne diseases complex ecosystems.

Detection of Anaplasma phagocytophilum in Dermacentor reticulatus ticks.

IN Europe, cases of Lyme borreliosis, tickborne encephalitis and granulocytic anaplasmosis have increased in human beings, domestic animals and wildlife, expanding their geographical ranges to much of Scandinavia and eastern Europe. Proposed explanations include improved surveillance and diagnosis,

Wild cervids are host for tick vectors of babesia species with zoonotic capability in Belgium.

Babesiosis is a tick-borne disease caused by different species of intraerythrocytic protozoan parasites within the genus Babesia. Different species of Babesia are described as potentially zoonotic and cause a malaria-like disease mainly in immunocompromised humans. Interest in the zoonotic potential of Babesia is growing and babesiosis has been described by some authors as an emergent zoonotic disease. The role of cervids to maintain tick populations and act as a reservoir host for some Babesia spp. with zoonotic capability is suspected. To investigate the range and infection rate of Babesia species, ticks were collected from wild cervids in southern Belgium during 2008. DNA extraction was performed for individual ticks, and each sample was evaluated for the absence of PCR inhibition using a PCR test. A Babesia spp. genus-specific PCR based on the 18S rRNA gene was applied to validated tick DNA extracts. A total of 1044 Ixodes ricinus ticks were collected and 1023 validated samples were subsequently screened for the presence of Babesia spp. DNA. Twenty-eight tick samples were found to be positive and identified after sequencing as containing DNA representing: Babesia divergens (3), B. divergens-like (5), Babesia sp. EU1 (11), Babesia sp. EU1-like (3), B. capreoli (2), or unknown Babesia sp. (4). This study confirms the presence of potentially zoonotic species and Babesia capreoli in Belgium, with a tick infection rate of 2.7% (95% CI 1.8,3.9%). Knowledge of the most common reservoir source for transmission of zoonotic Babesia spp. will be useful for models assessing the risk potential of this infection to humans.

Tickborne encephalitis virus antibodies in wild cervids in Belgium

TICKBORNE encephalitis (TBE) is currently a growing public health concern in Europe. An average of about 9000 reported human cases of TBE per year was recently reported for Europe and Russia between 1990 and 2007 (Donoso Mantke and others 2011). Until now, no cases of TBE have been reported from Belgium or from other countries such as the Netherlands, Luxembourg, Portugal, Spain, the UK, Ireland and Iceland. In 2011, serological screening in Belgian sentinel dogs detected one TBE-seropositive …