Identification of FactorsInfluencing the Puumala Virus Seroprevalence within Its Reservoir in aMontane Forest Environment

Abstract

Puumala virus (PUUV) is a major cause of mild to moderate haemorrhagic fever with renal syndrome and is transmitted by the bank vole (Myodes glareolus). There has been a high cumulative incidence of recorded human cases in South-eastern Germany since 2004 when the region was first recognized as being endemic for PUUV. As the area is well known for outdoor recreation and the Bavarian Forest National Park (BFNP) is located in the region, the increasing numbers of recorded cases are of concern. To understand the population and environmental effects on the seroprevalence of PUUV in bank voles we trapped small mammals at 23 sites along an elevation gradient from 317 to 1420m above sea level. Generalized linear mixed effects models(GLMEM) were used to explore associations between the seroprevalence of PUUV in bank voles and climate and biotic factors. We found that the seroprevalence of PUUV was low (6%–7%) in 2008 and 2009, and reached 29% in 2010. PUUV seroprevalence was positively associated with the local species diversity and deadwood layer, and negatively associated with mean annual temperature, mean annual solar radiation, and herb layer. Based on these findings, an illustrative risk map for PUUV seroprevalence prediction in bank voles was created for an area of the national park. The map will help when planning infrastructure in the national park (e.g., huts, shelters, and trails).

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

“…In Belgium, Linard et al (2007b) found that infected bank voles were common in the parts of the country that had a large proportion of broad-leaved forests. 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.…”

Spatial and Temporal Epidemiology of Nephropathia Epidemica Incidence and Hantavirus Seroprevalence in Rodent Hosts: Identification of the Main Environmental Factors in Europe

“…A negative association was found between host seroprevalence and temperature of previous autumn or winter (Linard et al., ; Tersago et al., ) or mean annual temperature (Thoma et al., ). This negative association echoes an experiment that documented longer periods of virus persistence outside the host with colder temperatures (Kallio et al.…”

“…Although a density‐dependent transmission rate of hantavirus in the rodent reservoir has been suggested (Clement et al., ), the expected relationship between host seroprevalence and density of the understory is not clear. Thus, although the number of captures was significantly higher in areas with dense ground vegetation (such as shrub layer cover) (Escutenaire et al., ), seasonal or annual host seroprevalence in dense ground vegetation was not significantly different from other habitats (Escutenaire et al., ; Thoma et al., ). In contrast, deadwood layer coverage, via the protection it provides, led to higher rodent density and was positively associated with seasonal or annual seroprevalence (Olsson et al., ; Thoma et al., ).…”

“…There was a negative association between annual or seasonal host seroprevalence and less attractive environments for rodents, such as herbs (Thoma et al., ), pines (Olsson et al., ) or 25‐ to 30‐year‐old forests (Voutilainen et al., ).…”

“…Accordingly and in favour of the hypothesis of indirect transmission, rodent seroprevalence was found to increase with cold winter and summer temperatures (Linard et al., ; Tersago et al., ), low mean annual temperature (Dobly et al., ; Thoma et al., ), spring precipitations (Tersago et al., ) or habitat humidity (Dobly et al., ; Verhagen et al., ). Sauvage et al.…”