Surveillance of sylvatic plaque in Oregon by serotesting carnivores.

In Oregon, during 1974-1979, 10.3 per cent of 3.255 statewide blood samples from carnivores were positive for Yersinia pestis. The per cent positive rate and geometric mean positive titer increase monthly from January (6.5 per cent) to June (21.7 per cent), and decline thereafter. Data are presented on how geographic location, species, and time of year affect surveillance results. The correlation of carnivore plague surveillance with human cases in discussed.