Network “Rodent-borne pathogens” in Germany: longitudinal studies on the geographical distribution and prevalence of hantavirus infections

Abstract

Hantavirus infections are known in Germany since the 1980s. While the overall antibody prevalence against hantaviruses in the general human population was estimated to be about 1-2%, an average of 100-200 clinical cases are recorded annually. In the years 2005 and 2007 in particular, a large increase of the number of human hantavirus infections in Germany was observed. The most affected regions were located in the federal states of Baden-Wuerttemberg, Bavaria, North Rhine Westphalia, and Lower Saxony. In contrast to the well-documented situation in humans, the knowledge of the geographical distribution and frequency of hantavirus infections in their rodent reservoirs as well as any changes thereof was very limited. Hence, the network "Rodent-borne pathogens" was established in Germany allowing synergistic investigations of the rodent population dynamics, the prevalence and evolution of hantaviruses and other rodent-associated pathogens as well as their underlying mechanisms in order to understand their impact on the frequency of human infections. A monitoring of hantaviruses in rodents from endemic regions (Baden-Wuerttemberg, Bavaria, North Rhine Westphalia, Lower Saxony) and regions with a low number of human cases (Mecklenburg Western-Pomerania, Brandenburg, Saxony, Saxony-Anhalt) was initiated. Within outbreak regions, a high prevalence of Puumala virus (PUUV) was detected in bank voles. Initial longitudinal studies in North Rhine Westphalia (city of Cologne), Bavaria (Lower Bavaria), and Lower Saxony (rural region close to Osnabrück) demonstrated a continuing presence of PUUV in the bank vole populations. These longitudinal studies will allow conclusions about the evolution of hantaviruses and other rodent-borne pathogens and changes in their distribution, which can be used for a risk assessment of human infections. This may become very important in order to evaluate changes in the epidemiology of rodent-borne pathogens in the light of expected global climate changes in the future.

Survey and case-control study during epidemics of Puumala virus infection

“…During epidemic times bank voles were trapped from different regions of Baden-Wuerttemberg. Between 20% and 76 % of them tested seropositive for PUUV [30]. A more effective spread of PUUV can be expected with increasing vole populations because as more voles become newly infected the excretion of virus peaks in the acute phase of infection, i.e.…”

Spatial and temporal variation of hantavirus bank vole infection in managed forest landscapes

“…In Germany, habitat structures associated with old forests such as dead wood was linked to increased probability of PUUV in bank voles within homogenous forest landscapes (Heyman et al 2012, Thoma et al 2014. Also, bank voles in wooded recreation areas and forested city parks were found to have high PUUV prevalence (Essbauer et al 2007, Ulrich et al 2008. In northern Sweden, bank voles prefer moist spruce forests (Hansson 1978, Olsson et al 2005) but to our knowledge, no boreal landscape studies focusing on PUUV infected voles and forest landscape structure have been done.…”

Rodents as Sentinels for the Prevalence of Tick-Borne Encephalitis Virus

“…1) between 2002 and 2008 and necropsied according to standard protocols established by the network ''Rodent-borne pathogens'' (Ulrich et al 2008). Briefly, the collected rodents were frozen and stored until necropsy.…”