Babesia sp. EU1

Yabsley, Michael J. & Shock, Barbara C., 2013, Natural history of Zoonotic Babesia: Role of wildlife reservoirs, International Journal for Parasitology: Parasites and Wildlife 2, pp. 18-31 : 24

2.2.3. Babesia sp. EU1

Babesia sp. EU1 was first recognized as a human pathogen in 1998 and was given the designation EU (European Union)-1 because the three initial cases occurred in asplenic patients from Italy and Austria ( Herwaldt et al., 2003). An additional case in an immunosuppressed patient from Germany has been reported. The infections ranged from mild to moderately severe, but none were fatal ( Herwaldt et al., 2003; Häselbarth et al., 2007). The name B. venatorum has been proposed, but a formal description has not been published ( Häselbarth et al., 2007).

Roe deer are the natural host of this parasite and infected deer have been reported from Slovenia, France and Italy ( Duh et al., 2005a; Bonnet et al., 2007b; Tampieri et al., 2008; Bastian et al., 2012). Prevalences in deer are generally high (>20%) ( Duh et al., 2005a; Bonnet et al., 2007b). No infections have been reported in sympatric red deer, although red deer are infected with B. capreoli ( Duh et al., 2005a) . Disease due to B. sp. EU1 has been reported for a captive reindeer ( R. tarandus ) in a zoo in The Netherlands ( Kik et al., 2011).

The only known vector of B. sp. EU1 is I. ricinus , and similar to B. divergens , infected ticks have been reported throughout Europe including Estonia, Switzerland, Poland, Italy, Belgium, Germany, France, Netherlands, Norway, and Slovenia ( Duh et al., 2005b; Casati et al., 2006; Schmid et al., 2008; Cieniuch et al., 2009; Wielinga et al., 2009; Cassini et al., 2010; Burri et al., 2011; Gigandet et al., 2011; Katargina et al., 2011; Reis et al., 2011; Schorn et al., 2011; Capelli et al., 2012; Lempereur et al., 2012; Oines et al., 2012). Transovarial and transstadial transmission of B. sp. EU1 by I. ricinus has been documented ( Bonnet et al., 2007b, 2009; Mazyad et al., 2010), but in general, prevalences in I. ricinus are low (<2%) ( Cieniuch et al., 2009; Cassini et al., 2010; Katargina et al., 2011; Oines et al., 2012).

Interestingly, this Babesia has been detected in I. ricinus removed from passerines that migrated to Norway and northwestern Russia, suggesting a risk for establishment in countries currently north of the known distribution ( Hasle et al., 2011; Movila et al., 2011). A Babesia , closely related or identical to B. sp. EU1 have been detected in Ixodes persulcatus from the Novosibirsk region of Russia ( Rar et al., 2011), but a survey of this tick species in Estonia failed to detect B. sp. EU1 ( Katargina et al., 2011).