Failure to demonstrate the maintenance of leptospires by house mice (Mus musculus) in the south east of England.

A total of 272 house mice (Mus musculus) were trapped in farm buildings at four widely separated locations of south east England and examined for serological and bacteriological evidence of leptospiral infection. Only two low titres to autumnalis antigen (1:20 and 1:40) were recorded and all mice were bacteriologically negative. The absence of leptospiral infection in the house mouse in south east England is an interesting ecological finding, as this species is a maintenance host for ballum in many countries and also a common carrier of several other serovars. The source of ballum infections in domestic stock in England remains unknown.