Spatial and temporal dynamics of Puumala hantavirus infection in red bank vole (Clethrionomys glareolus) populations in Belgium

Dynamics of hantavirus infection and population densities in rodents were i nvestigated from 1996 to 1999 in southern Belgium. Evidence of Puumala infe ction was restricted to Clethrionomys glareolus. Although the serotype was not determined, antibodies against hantavirus were also found in eight Apod emus sylvaticus. In fall 1996, the seroprevalence in C. glareolus was high (20.1%, 37 of 184) and the infection was widely distributed in the area stu died whereas a focal occurrence of positive rodents and lower seroprevalenc e rates were recorded in spring 1997 (14.3%, six of 42), fall 1997 (6.6%, 1 1 of 166), spring 1998 (6.4%, three of 47) and fall 1998 (6.7%, 11 of 165). A pullulation of rodents was observed in spring 1999 and was associated wi th a markedly higher seroprevalence in C. glareolus (47.7%, 189 of 396). In all seasons, infection rates in adults were higher than in juveniles and s ubadults. No significant difference of prevalence was recorded between male s and females. In two trapping sites, the temporary disappearance of positi ve animals after a crash in rodent populations suggests that a threshold in density is necessary for the maintenance of the enzootic cycle. (C) 2090 E lsevier Science B.V. All rights reserved.