Tularemia in Germany: the tip of the iceberg?

Abstract

Tularemia is a rare, notifiable zoonosis in Germany. Since November 2004, several lines of evidence including outbreaks in humans or animals and confirmed infections in indigenous hare and rodent populations have indicated a re-emergence of tularemia in different German federal states. Unfortunately, reliable basic information on the seroprevalence in different geographical regions, permitting the identification of risk factors, does not exist. Combining a sensitive screening assay with a highly specific confirmative immunoblot test, we performed a serological investigation on 2416 sera from a population-based, cross-sectional health survey of the city population of Leutkirch, Baden-Wuerttemberg. A total of 56 sera gave positive results indicating a seroprevalence of 2.32%. Thus, the seroprevalence is tenfold higher than that previously reported in a nationwide study in 2004. Francisella tularensis can cause a wide variety of clinical syndromes including severe, sometimes fatal disease. Missing epidemiological data on its spatial and temporal distribution in an endemic country complicate an appropriate risk assessment necessary for public health authorities to be prepared for an adequate outbreak management. This is of special concern regarding the extraordinary potential of F. tularensis as an agent of bioterrorism. Our investigation performed in a presumed low-risk area demonstrated that tularemia might be seriously underestimated in Germany and probably in other central European countries as well.

The status of tularemia in Europe in a one-health context: a review

“…Tularemia often presents with non-specific symptoms, which may delay its diagnosis. Sporadic human cases are often missed, particularly in areas which are assumed to have a low incidence of the disease [6]; this may lead to inefficient or delayed treatment, which may result in more severe manifestations of the disease. Tularemia has a broad geographical distribution, with sporadic cases and/or outbreaks occurring in many European countries.…”

Serological Investigation of Wild Boars (Sus scrofa) and Red Foxes (Vulpes vulpes) As Indicator Animals for Circulation ofFrancisella tularensisin Germany

“…In Europe, tularemia is exclusively caused by F. tularensis subsp. holarctica and mainly transmitted by contact with infected brown hares (Lepus europaeus) (Mö rner et al 1988, Anonymous 2000, Strauss and Pohlmeyer 2001, Anonymous 2002, Pikula et al 2004, Keim et al 2007, Splettstoesser et al 2009, Gyuranecz et al 2010. Transmission occurs by dermal and mucosal contact, orally, through contaminated aerosols, or by arthropod bites.…”

“…Tularemia is an autochthonous zoonosis in Germany, but imported cases have also been described (Schubert et al 2011). However, studies on the natural reservoir and vectors and the resulting potential exposure of the human population are only fragmentary and practically incomparable (Kaysser et al 2008, Splettstoesser et al 2009, Decors et al 2011, Kuehn et al 2013.…”

Prevalence of Francisella tularensis in brown hare (Lepus europaeus) populations in Lower Saxony, Germany

“…In 2007, the highest number of human infections of tularemia since 1958 was registered. It seems that tularemia is re-emerging in Germany (Hauri et al 2010;Müller et al 2007;Splettstoesser et al 2009). …”