Dubey and Frenkel,362 Afonso et al.,9 and Dabritz et al.212 tabulated worldwide serologic T. gondii prevalence in rodents; I have not repeated them here.

The method used for T. gondii examination of rodents is critical. Serological surveys are the easiest, but specicity and sensitivity depends on the test, and the dilution of serum tested. As an example, Webster1343 reported a high (35%) seroprevalence in 235 rats from farms in England, but the study was based on 1:10 titer in the LAT, which is a very insensitive test and titers below 1:32 are regarded nonspecic. Conrmation of positive samples was sought by IgG-ELISA and by direct microscopic examination of the rat brains for T. gondii tissue cysts. The percentage of sera and brains that were so checked was not indicated.362 She proposed that T. gondii infection can be maintained in the absence of cats on some farms.1343 It is unfortunate that such a profound statement was based on a 1:10 titer in LAT.362