THE COMPLEXITIES AT THE INTERFACE AMONG DOMESTIC/WILD RODENTS, FLEAS, PETS, AND MAN IN URBAN PLAGUE ECOLOGY IN LOS ANGELES, COUNTY, CALIFORNIA

Bubonic plague was first found in Los Angeles County in 1908. The largest epidemic of pneumonic plague in the United States occurred in the county in 1924, and the last cases of plague associated with domestic rodents in the United States occurred here in 1925. Sporadic plague activity was recorded from 1925 to 1975. Since 1975, plague has been found annually and is now endemic in the San Gabriel Mountains and the interface, that area where suburban encroachment intermingles with wilderness areas along the southern edge of these mountains. Within these two areas, plague is amplified and is a risk to humans when it occurs in the California ground squirrel, Spermophilus beecheyi. This rodent has been implicated directly in two human cases, and is now peridomestic throughout most of the interface area. A domestic cat was implicated with another case; the role of domestic pets in plague ecology is discussed. Although large populations of Rattus rattus exist within the interface, they currently play no role in plague ecology due to the virtual absence of fleas. The oriental rat flea, however, is seasonally very abundant in Rattus norvegicus living adjacent to the interface area and poses an alarming potential for epidemics if plague ever was introduced into this host population. The plague surveillance program in Los Angeles County centers on an active intelligence network to report signs of plague activity and on the combined use of serologies taken from wild carnivores and S. beecheyi. Early detection by these means plus active flea and ground squirrel suppression programs have been implemented to reduce plague activity and prevent human cases

AN INTEGRATED PEST MANAGEMENT APPROACH TO ROOF RAT CONTROL IN OCEANFRONT RIPRAP, VENTURA COUNTY, CALIFORNIA

During the summer months of 1979, public agencies in Ventura County received complaints which pointed to a rodent infestation of campground areas along the north coastal strip. Investigations revealed a widespread infestation of oceanfront riprap by roof rats (Rattus rattus). Visual surveillance, trapping, baiting and population-estimating techniques and results are described and discussed. Implementation of integrated pest management practices resulted in the reduction of rat populations to a no-complaint level and provided a framework for a long-term maintenance program

The complexities at the interface among domestic/wild rodents, fleas, pets, and man in urban plague ecology in Los Angeles County, California

Bubonic plague was first found in Los Angeles County in 1908. The largest epidemic of pneumonic plague in the United States occurred in the county in 1924, and the last cases of plague associated with domestic rodents in the United States occurred here in 1925. Sporadic plague activity was recorded from 1925 to 1975. Since 1975, plague has been found annually and is now endemic in the San Gabriel Mountains and the interface, that area where suburban encroachment intermingles with wilderness areas along the southern edge of these mountains. Within these two areas, plague is amplified and is a risk to humans when it occurs in the California ground squirrel, Spermophilus beecheyi. This rodent has been implicated directly in two human cases and is now peridomestic throughout most of the interface area. A domestic cat was implicated with another case; the role of domestic pets in plague ecology is discussed. Although large populations of Rattus rattus exist within the interface, they currently play no role in plague ecology due to the virtual absence of fleas. The oriental rat flea, however, is seasonally very abundant in Rattus norvegicus living adjacent to the interface area and poses an alarming potential for epidemics if plague ever was introduced into this host population. The plague surveillance program in Los Angeles County centers on an active intelligence network to report signs of plague activity and on the combined use of serologies taken from wild carnivores and S. beecheyi. Early detection by these means plus active flea and ground squirrel suppression programs have been implemented to reduce plague activity and prevent human cases

An integrated pest management approach to roof rat control in oceanfront riprap, Ventura County, California

During the summer months of 1979, public agencies in Ventura County, CA, received complaints which pointed to a rodent infestation of campground areas along the north coastal strip. Investigations revealed a widespread infestation of oceanfront riprap by roof rats (Rattus rattus). Visual surveillance, trapping, baiting and population-estimating techniques and results are described and discussed. Implementation of integrated pest management practices resulted in the reduction of rat populations to a no-complaint level and provided a framework for a long-term maintenance program

Seroepidemiologic Studies of Hantavirus Infection Among Wild Rodents in California

A total of 4,626 mammals were serologically tested for antibodies to Sin Nombre virus. All nonrodent species were antibody negative. Among wild rodents, antibody prevalence was 8.5% in murids, 1.4% in heteromyids, and 1,200 meters) and correlated with a spatial cluster of hantavirus pulmonary syndrome cases in the Sierra Nevada