Role of maternal antibody in natural infection of Peromyscus maniculatus with Sin Nombre virus.
Data from naturally infected deer mice (Peromyscus maniculatus) were used to investigate vertical transmission of Sin Nombre virus (SNV) and SNV-specific antibody. The antibody prevalence in juvenile mice (14 g or less) was inversely proportional to the mass of the animal, with juvenile deer mice weighing less than 11 g most likely to be antibody positive (26.9%) and juvenile mice weighing between 13 and 14 g least likely to be antibody positive (12.9%). Although a significant sex bias in seropositivity was detected in adult deer mice, no significant sex bias in seropositivity was detected in juvenile animals. Ten juvenile deer mice were identified that had initially tested positive for SNV-specific immunoglobulin G (IgG) by enzyme-linked immunosorbent assay (ELISA) but had subsequently tested negative when recaptured as adults. SNV RNA was detected by reverse transcriptase PCR (RT-PCR) in the blood of ELISA-positive adult deer mice but not in the blood of ELISA-positive juveniles. One of the juvenile mice initially tested negative for SNV RNA but later tested positive when recaptured as an ELISA-positive adult. The RT-PCR results for that individual correlated with the disappearance and then reappearance of SNV-specific IgG, indicating that the presence of SNV RNA at later time points was due to infection with SNV via horizontal transmission. SNV-specific antibody present in both ELISA-positive juvenile and adult mice was capable of neutralizing SNV. Additionally, our data indicate that SNV is not transmitted vertically. (+info)
Outbreaks of Salmonella serotype enteritidis infection associated with eating raw or undercooked shell eggs--United States, 1996-1998.
During the 1980s and 1990s, Salmonella serotype Enteritidis (SE) emerged as an important cause of human illness in the United States. The rate of SE isolates reported to CDC increased from 0.6 per 100,000 population in 1976 to 3.6 per 100,000 in 1996 (Figure 1). Case-control studies of sporadic infections and outbreak investigations found that this increase was associated with eating raw or undercooked shell eggs (1). From 1996 to 1998, the rate of culture-confirmed SE cases reported to CDC declined to 2.2 per 100,000; however, outbreaks of illness caused by SE continue to occur. This report describes four SE outbreaks during 1996-1998 associated with eating raw or undercooked shell eggs and discusses measures that may be contributing to the decline in culture-confirmed SE cases. (+info)
Remote sensing and geographic information systems: charting Sin Nombre virus infections in deer mice.
We tested environmental data from remote sensing and geographic information system maps as indicators of Sin Nombre virus (SNV) infections in deer mouse (Peromyscus maniculatus) populations in the Walker River Basin, Nevada and California. We determined by serologic testing the presence of SNV infections in deer mice from 144 field sites. We used remote sensing and geographic information systems data to characterize the vegetation type and density, elevation, slope, and hydrologic features of each site. The data retroactively predicted infection status of deer mice with up to 80% accuracy. If models of SNV temporal dynamics can be integrated with baseline spatial models, human risk for infection may be assessed with reasonable accuracy. (+info)
Nevada State plan; final approval determination. Occupational Safety and Health Administration (OSHA), U.S. Department of Labor. Final State plan approval--Nevada.
This document amends OSHA's regulations to reflect the Assistant Secretary's decision granting final approval to the Nevada State plan. As a result of this affirmative determination under section 18(e) of the Occupational Safety and Health Act of 1970, Federal OSHA's standards and enforcement authority no longer apply to occupational safety and health issues covered by the Nevada plan, and authority for Federal concurrent jurisdiction is relinquished. Federal enforcement jurisdiction is retained over any private sector maritime employment, private sector employers on Indian land, and any contractors or subcontractors on any Federal establishment where the land is exclusive Federal jurisdiction. Federal jurisdiction remains in effect with respect to Federal government employers and employees. Federal OSHA will also retain authority for coverage of the United States Postal Service (USPS), including USPS employees, contract employees, and contractor-operated facilities engaged in USPS mail operations. (+info)
Mycoplasma agassizii sp. nov., isolated from the upper respiratory tract of the desert tortoise (Gopherus agassizii) and the gopher tortoise (Gopherus polyphemus).
Biochemical, serological and molecular genetic studies were performed on seven mycoplasma isolates that were recovered from the upper respiratory tract of clinically ill desert tortoises. The isolates were serologically related to each other but serologically distinct from previously described species. Unique mycoplasma species-specific 16S rRNA nucleotide sequences were found in the proposed type strain. The name Mycoplasma agassizii is proposed for these isolates. The type strain is PS6T (= ATCC 700616T) which caused upper respiratory tract disease (URTD) in experimentally infected tortoises. (+info)
Paired city cryptosporidium serosurvey in the southwest USA.
In 1996, serological responses to two Cryptosporidium antigens were determined for 200 Las Vegas (LV), Nevada, and 200 Albuquerque, New Mexico, blood donors to evaluate associations between endemic infections, water exposures, and other risk factors. LV uses chlorinated filtered drinking water from Lake Mead while Albuquerque uses chlorinated ground water. The intensity of serological response to both markers was higher for older donors (P < 0.05). donors who washed food with bottled water (P < 0.05) and donors from LV (P < 0.05). A decreased serological response was not associated with bottled water consumption, nor was an increased response associated with self-reported cryptosporidiosis-like illness or residence in LV at the time of a cryptosporidiosis outbreak 2 years earlier. Although these findings suggest the serological response may be associated with type of tap water and certain foods, additional research is needed to clarifythe role of both food and drinking water in endemic Cryptosporidium infection. (+info)
A comparison of three staff-management procedures.
Even though administrators must have effective staff-management procedures to ensure implementation of desired programs, many traditional staff-management proceudres remain unevaluated. This study investigated the effectiveness of three such procedures. The administrator of an institution for the retarded (1) sent a memo instructing all staff to lead daily recreational activities, (2) sponsored a workshop teaching staff to lead such activities, and (3) assigned staff activity leaders and provided performance feedback to staff by publicly posting the daily average number of active residents on each ward. Neither the memo nor the workshops motivated staff to lead activities, but after staff were scheduled to lead such activities and given performance feedback, the average daily number of residents engaged in activities on four wards for 95 retarded persons increased from seven to 32. The administration of this facility has adopted similar procedures to maintain such activities on all wards. (+info)
Collapse of the California Current during glacial maxima linked to climate change on land.
Time series of alkenone unsaturation indices gathered along the California margin reveal large (4 degrees to 8 degrees C) glacial-interglacial changes in sea surface temperature (SST) over the past 550,000 years. Interglacial times with SSTs equal to or exceeding that of the Holocene contain peak abundances in the pollen of redwood, the distinctive component of the temperate rainforest of the northwest coast of California. In the region now dominated by the California Current, SSTs warmed 10,000 to 15,000 years in advance of deglaciation at each of the past five glacial maxima. SSTs did not rise in advance of deglaciation south of the modern California Current front. Glacial warming along the California margin therefore is a regional signal of the weakening of the California Current during times when large ice sheets reorganized wind systems over the North Pacific. Both the timing and magnitude of the SST estimates suggest that the Devils Hole (Nevada) calcite record represents regional but not global paleotemperatures, and hence does not pose a fundamental challenge to the orbital ("Milankovitch") theory of the Ice Ages. (+info)