Common voles and field voles as main reservoir for Leptospira kirschneri in Germany

Leptospirosis is a widespread zoonosis occurring in humans, domestic and compan-ion animals. In temperate areas Leptospira usually causes sporadic epidemics. In Germany, the incidence increased in 2007 and 2014 due to disease clusters among strawberry harvesters in North Rhine-Westphalia and Lower Saxony. The objective of this study was to evaluate the small mammal host specificity of Leptospira. Small mammals were trapped in spring, summer and autumn between 2010 and 2014 in forest and grassland habitats at four locations in Germany in Mecklenburg-Western Pomerania, North Rhine-Westphalia, Thuringia and Baden-Wuerttemberg. Using an initial screening PCR, 524 of 3,950 (13.3%) small mammals were tested positive for Leptospira specific DNA. Leptospira DNA was detected in six rodent and three shrew species. Common voles (Microtus arvalis) and field voles (Microtus agrestis) were more frequently infected by Leptospira kirschneri than any other small mammal species. In contrast, bank voles, yellow-necked mice and common shrews were infected with multiple Leptospira species. The study confirms a broad geographical distribution of Leptospira across small mammal reservoir species and suggests an important public health relevance espe-cially of common voles and field voles as reservoirs of L. kirschneri. Further inves-tigations should focus on population dynamics of common voles and field voles and their impact on the Leptospira prevalence and its putative influence on the human infection risk, especially for risk groups, such as field and forestry workers.