High Prevalence of Tula Hantavirus in Common Voles in The Netherlands

Tula virus (TULV) is a zoonotic hantavirus. Knowledge about TULV in the Netherlands is very scarce. Therefore in 2014, 49 common voles (Microtus arvalis) from a region in the south of the Netherlands, and in 2015, 241 common voles from regions in the north of the Netherlands were tested with the TULV quantitative RT-PCR. In the southern region, prevalence of TULV was 41% (20/49). In the northern regions, prevalence ranged from 12% (4/34) to 45% (17/38). Phylogenetic analysis of the obtained sequences showed that the regions fall within different clusters. Voles from the south were also tested on-site for the presence of hantavirus antibodies, but serology results were poorly associated with qRT-PCR results. These findings suggest that TULV may be more widespread than previously thought. No human TULV cases have been reported thus far in the Netherlands, but differentiation between infection by TULV or the closely related Puumala virus is not made in humans in the Netherlands, thus cases may be misdiagnosed.