56 research outputs found
Emerging Pattern of Rabies Deaths and Increased Viral Infectivity
Most human rabies deaths in the United States can be attributed to unrecognized exposures to rabies viruses associated with bats, particularly those associated with two infrequently encountered bat species (Lasionycteris noctivagans and Pipistrellus subflavus). These human rabies cases tend to cluster in the southeastern and northwestern United States. In these regions, most rabies deaths associated with bats in nonhuman terrestrial mammals are also associated with virus variants specific to these two bat species rather than more common bat species; outside of these regions, more common bat rabies viruses contribute to most transmissions. The preponderance of rabies deaths connected with the two uncommon L. noctivagans and P. subflavus bat rabies viruses is best explained by their evolution of increased viral infectivity
The Eco-Epidemiology of Pacific Coast Tick Fever in California
Rickettsia philipii (type strain âRickettsia 364Dâ), the etiologic agent of Pacific Coast tick fever (PCTF), is transmitted to people by the Pacific Coast tick, Dermacentor occidentalis. Following the first confirmed human case of PCTF in 2008, 13 additional human cases have been reported in California, more than half of which were pediatric cases. The most common features of PCTF are the presence of at least one necrotic lesion known as an eschar (100%), fever (85%), and headache (79%); four case-patients required hospitalization and four had multiple eschars. Findings presented here implicate the nymphal or larval stages of D. occidentalis as the primary vectors of R. philipii to people. Peak transmission risk from ticks to people occurs in late summer. Rickettsia philipii DNA was detected in D. occidentalis ticks from 15 of 37 California counties. Similarly, non-pathogenic Rickettsia rhipicephali DNA was detected in D. occidentalis in 29 of 38 counties with an average prevalence of 12.0% in adult ticks. In total, 5,601 ticks tested from 2009 through 2015 yielded an overall R. philipii infection prevalence of 2.1% in adults, 0.9% in nymphs and a minimum infection prevalence of 0.4% in larval pools. Although most human cases of PCTF have been reported from northern California, acarological surveillance suggests that R. philipii may occur throughout the distribution range of D. occidentalis
Phylogenetic relationships of platanistoid river dolphins (Odontoceti, Cetacea): assessing the significance of fossil taxa
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Assessing Prevention Measures and Sin Nombre Hantavirus Seroprevalence Among Workers at Yosemite National Park
Background During 2012, a total of 10 overnight visitors to Yosemite National Park (Yosemite) became infected with a hantavirus (Sin Nombre virus [SNV]); three died. SNV infections have been identified among persons with occupational exposure to deer mice (Peromyscus maniculatus).
Methods We assessed SNV infection prevalence, work and living environments, mice exposures, and SNV prevention training, knowledge, and practices among workers of two major employers at Yosemite during SeptemberâOctober, 2012 by voluntary blood testing and a questionnaire.
Results One of 526 participants had evidence of previous SNV infection. Participants reported frequently observing rodent infestations at work and home and not always following prescribed safety practices for tasks, including infestation cleanup.
Conclusion Although participants had multiple exposures to deer mice, we did not find evidence of widespread SNV infections. Nevertheless, employees working around deer mice should receive appropriate training and consistently follow prevention policies for high-risk activities
Identification of New Rabies Virus Variant in Mexican Immigrant
A novel rabies virus was identified after death in a man who had immigrated from Oaxaca, Mexico, to California, USA. Despite the patientâs history of exposure to domestic and wild carnivores, molecular and phylogenetic characterizations suggested that the virus originated from insectivorous bats. Enhanced surveillance is needed to elucidate likely reservoirs
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. We identified SNV antibodies in 40% of cactus mice sampled
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