experimental plague in the california ground experiments to determine the current susceptibility to plague, it was demonstrated that 256 yersinia pestis (a local strain of high virulence) were required to produce a 50% infectious dose (id50) in california ground squirrels (spermophilus beecheyi) that had been collected in southeastern monterey county, california; 6,070 y. pestis were required to produce a 50% lethal dose (ld50). (the ld50 was about 24 times the id50.) the frequency of serologic response to the specific fraction 1 antige ...1979512421
flea, rodent, and plague ecology at chuchupate campground, ventura county, california.chuchupate campground in ventura county, california, was closed to the public for 18 years (1982 to 2000) because of uncontrolled vector fleas and persistent plague antibody titers in rodents. the primary purpose of this study was to clarify the plague ecology of chuchupate campground by identifying involved rodents and their vector fleas and by determining many of their ecological parameters: abundance, flea and host preferences and diversities, and flea seasonality. rodents and fleas were iden ...200212125863
ectoparasite diversity and exposure to vector-borne disease agents in wild rodents in central coastal california.a survey of wild rodents was performed in the morro bay area of central coastal california to determine serological and polymerase chain reaction (pcr) prevalence of anaplasma phagocytophilum dumler, barbet, bekker, dasch, palmer, ray, rikihisa, and rurangirwa, borrelia burgdorferi johnson, schmidt, hyde, steigerwalt, and brenner, francisella tularensis mccoy, and yersinia pestis yersin; to describe the ectoparasitic fauna on important vector-borne disease hosts; and to determine whether pathoge ...200717427705
use of a chitin synthesis inhibitor to control fleas on wild rodents important in the maintenance of plague, yersinia pestis, in california.a study was designed to test the insect development inhibitors fluazuron and lufenuron for the control of fleas on sylvatic rodents as an adjunct to the control of plague. historical data of flea burden from 15 prior years of study at chuchupate campground, ventura county, ca, were compared to six years of treatment period data to determine if fluazuron and lufenuron were effective in controlling flea densities. the insect development inhibitors, delivered systemically via a feed cube, reduced f ...200819263847
spatial analysis of plague in california: niche modeling predictions of the current distribution and potential response to climate change.plague, caused by the bacterium yersinia pestis, is a public and wildlife health concern in california and the western united states. this study explores the spatial characteristics of positive plague samples in california and tests maxent, a machine-learning method that can be used to develop niche-based models from presence-only data, for mapping the potential distribution of plague foci. maxent models were constructed using geocoded seroprevalence data from surveillance of california ground s ...200919558717
seasonal and among-site variation in the occurrence and abundance of fleas on california ground squirrels (otospermophilus beecheyi).an improved understanding of the ecology of fleas on california ground squirrels, otospermophilus beecheyi, is warranted given the role of fleas in the transmission, and perhaps persistence, of the plague-causing bacterium yersinia pestis. we sampled o. beecheyi on a seasonal basis from three study sites, each representing a different land use type (preserve, pasture, and agriculture) in the san joaquin valley, ca. overall, the abundance of fleas on squirrels was greatest in spring at the preser ...201121635649
disease surveillance of california ground squirrels ( spermophilus beecheyi ) in a drive-through zoo in oregon, usa.rodents and other small wild mammals are often considered to be pests and vectors for disease in zoos that house small populations of valuable threatened and endangered animals. in 2005, three nonhuman primates at a drive-through zoo in oregon, us, acquired tularemia from an unknown source. due to an abundance of california ground squirrels ( spermophilus beecheyi ) on zoo grounds, we instituted serosurveillance of this species from july through september 2008 to determine the prevalence of anti ...201728418764
Displaying items 1 - 7 of 7