Novel Focus of Sin Nombre Virus in Peromyscus eremicus Mice, Death Valley National Park, California, USA.

The deer mouse (Peromyscus maniculatus) is the primary reservoir for Sin Nombre virus (SNV) in the western United States. Rodent surveillance for hantavirus in Death Valley National Park, California, USA, revealed cactus mice (P. eremicus) as a possible focal reservoir for SNV in this location.

Public health pesticide use in California: a comparative summary.

California pesticide use summary data and use reports from local vector control agencies were reviewed to document public health pesticide use patterns. During the 15-year period 1993-2007, public health pesticide use averaged 1.75 million lb (0.

Clinical, epidemiologic, and environmental surveillance for ehrlichiosis and anaplasmosis in an endemic area of northern California.

Two forms of tick-borne leukocytotropic rickettsioses have been recognized in California since the mid-1990s: human monocytic ehrlichiosis (HME) caused by Ehrlichia chaffeensis and human granulocytic anaplasmosis (HGA) caused by Anaplasma phagocytophilum. Between 1997 and 1999, two cases of HME and four cases of HGA were diagnosed in residents of southern Humboldt County, California. Environmental followup at case-patients' residences revealed dense populations of Ixodes pacificus ticks, particularly in grassy roadside areas.

Isolation and characterization of Borrelia hermsii associated with two foci of tick-borne relapsing fever in California.

Relapsing fever, caused by the spirochete Borrelia hermsii and transmitted by the soft tick Ornithodoros hermsi, is endemic in many rural mountainous areas of California. Between 1996 and 1998, 12 cases of relapsing fever associated with two exposure sites in northern California were investigated. Follow-up at exposure sites included collection of soft ticks and serum specimens from sylvatic rodents.

Use of liquid deltamethrin in modified, host-targeted bait tubes for control of fleas on sciurid rodents in northern California.

The efficacy of liquid deltamethrin was evaluated for controlling fleas on golden-mantled ground squirrels, Spermophilus lateralis, and chipmunks, Tamias amoenus and T. senex. A host-targeted bait tube was modified to deliver insecticide to visiting rodents during a seven-week trial conducted in the Southern Cascade Mountains of northern California.

Aged men display blunted biorhythmic variation of muscle performance and physiological responses.

Aging is known to disrupt the "biological clock" that governs physiological variables at rest. This study sought to determine whether aged men demonstrated biorhythmic variation in muscle performance during resistance exercise and physiological responses to that stimulus. Ten aged (75.

Experimental and field evaluations of two acaracides for control of I. pacificus (Acari: Ixodidae) in northern California.

Use of acaricides for the control of Ixodes pacificus (Cooley & Kohls), the vector of Lyme borreliosis in the western United States, can be a beneficial component in a program to reduce the morbidity of Lyme borreliosis in California. Three commercially available acaricides, carbaryl, chlorpyrifos, and diazinon, were evaluated in laboratory bioassays for their effectiveness against I. pacificus adults.

Sarcoidosis of the paranasal sinuses with orbital extension.

A 21-year-old black man with unilateral proptosis and decreased visual acuity was shown to have sarcoidosis of the paranasal sinuses with secondary invasion of the orbit, as demonstrated by contact B-scan ultrasonography, sinus tomography, surgical exploration, and biopsy.

FURTHER STUDIES OF THE INFECTIOUS UNIT OF VACCINIA.

A study has been made of the comparative virulence of several strains of vaccine virus for a number of hosts, and wide variation in animal susceptibility has been demonstrated. The results obtained in experiments with a chick-embryo-adapted strain are interpreted as indicating that the particles of virus are of essentially uniform virulence. Results of statistical analyses are presented which indicate that as the virulence of a strain of virus increases the number of elementary bodies per infectious unit approaches 1, and at that limit the chance of infection is governed primarily by the presence or absence of virus in the inoculum.