No abstract

From 1983 to 1985, 463 serum samples from 11 species of mammals in Redwood National Park (RNP) (California, USA) were evaluated for antibodies to Yerslnia pestis by the passive hemagglutination method. This is the first report of Y. pestis infection in Redwood National Park, and the first detailed report of Y. pestis activity in a temperate rainforest.

No abstract

Roof rats (Rattus rattus) in southern California are rarely involved with plague epizootics and murine typhus. Little evidence exists implicating these rodents as sources of human infection. This might be explained by the absence of fleas capable of transmitting these 2 diseases. From February 1981 through January 1982, roof rats were live-trapped and examined for fleas each month in 4 areas of Los Angeles County. Two other areas were trapped for 9 and 3 months respectively. Areas sampled were in or near the suburban-wilderness fringe where plague and murine typhus occur, and where roof rats coexist with a variety of wild and domestic mammals and humans. From 1,206 roof rats, 827 fleas belonging to eight species were collected. Leptopsylla segnis (54%) and Nosopsyllus fasciatus (39%) were the most abundant and together comprised 93% of all fleas. Xenopsylla cheopis was not found. The relative abundance and diversity of fleas on roof rats varied considerably between areas, making it difficult to predict flea diversity and abundance in unsurveyed areas where similar conditions exist. However, the overall low flea indices and the absence of X. cheopis help to explain why roof rats in Los Angeles County are rarely involved with plague and murine typhus.