Publications by authors named "Joseph Singleton"

In this paper we present a modal logic framework to reason about the expertise of information sources. A source is considered an expert on a proposition if they are able to correctly refute in any possible world where is false. Closely connected with expertise is a notion of : is said to be "sound" if it is true of the source.

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Background: The disaccharide galactose-α-1,3-galactose (alpha-gal) is expressed in mammals other than humans, apes, and old-world monkeys. In humans, elevated immunoglobulin E (IgE) antibodies specific for alpha-gal can result in allergic hypersensitivity known as alpha-gal syndrome (AGS). Case reports and series suggest that tick bites can induce alpha-gal-specific IgE (sIgE) antibodies.

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Understanding the distribution of pathogens causing acute febrile illness (AFI) is important for clinical management of patients in resource-poor settings. We evaluated the proportion of AFI caused by specific pathogens among outpatients in Bangladesh. During May 2019-March 2020, physicians screened patients aged ≥2 years in outpatient departments of four tertiary level public hospitals.

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rickettsiosis is an emerging, tick-borne disease in the United States (US), transmitted by the bite of group ticks. Clinical manifestations include fever, headache, myalgia, maculopapular rash, and a characteristic eschar that forms at the site of the tick bite. Arizona's index case of rickettsiosis was reported in 2014.

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Chikungunya, a mosquito-borne viral, acute febrile illness (AFI) is associated with polyarthralgia and polyarthritis. Differentiation from other AFI is difficult due to the non-specific presentation and limited availability of diagnostics. This 3-year study identified independent clinical predictors by day post-illness onset (DPO) at presentation and age-group that distinguish chikungunya cases from two groups: other AFI and dengue.

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Background: Since 2000, the reported prevalence of tick-borne spotted fever rickettsiosis has increased considerably. We compared the level of antibody reactivity among healthy blood donors from 2 widely separated regions of the United States and evaluated the impact of antibody prevalence on public health surveillance in one of these regions.

Methods: Donor serum samples were evaluated by indirect immunofluorescence antibody assay to identify immunoglobulin G (IgG) antibodies reactive with Rickettsia rickettsii.

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Identifying etiologies of acute febrile illnesses (AFI) is challenging due to non-specific presentation and limited availability of diagnostics. Prospective AFI studies provide a methodology to describe the syndrome by age and etiology, findings that can be used to develop case definitions and multiplexed diagnostics to optimize management. We conducted a 3-year prospective AFI study in Puerto Rico.

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In the United States, all previously reported cases of Rickettsia parkeri rickettsiosis have been linked to transmission by the Gulf Coast tick (Amblyomma maculatum). Here we describe 1 confirmed and 1 probable case of R. parkeri rickettsiosis acquired in a mountainous region of southern Arizona, well beyond the recognized geographic range of A.

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An evaluation of chitosan gelling fibre dressing (KytoCel, Aspen Medical) was undertaken by tissue viability nurses in a large acute trust from December 2014--May 2015. The aim of this evaluation was to examine whether the gelling-fibre dressing can improve healing outcomes--reduction of bioburden and promotion of wound healing in both acute and chronic wounds that are infected or critically colonised. A total of 20 patients were recruited with acute and other complex wounds where wound infection was already established, or an excessive wound bioburden was delaying healing.

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Coxiella burnetii is a zoonotic pathogen that causes Q fever in humans and is transmitted primarily from infected goats, sheep, or cows. Q fever typically presents as an acute febrile illness; however, individuals with certain predisposing conditions, including cardiac valvulopathy, are at risk for chronic Q fever, a serious manifestation that may present as endocarditis. In response to a cluster of Q fever cases detected by public health surveillance, we evaluated C.

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Rickettsia parkeri, a newly recognized tick-borne pathogen of humans in the Americas, is a confirmed cause of spotted fever group rickettsiosis in Argentina. Until recently, almost all cases of R. parkeri rickettsiosis in Argentina have originated from the Paraná River Delta, where entomological surveys have identified populations of R.

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Among 13 suspected Rocky Mountain spotted fever (RMSF) cases identified through an enhanced surveillance program in Tennessee, antibodies to Rickettsia rickettsii were detected in 10 (77%) patients using a standard indirect immunofluorescent antibody (IFA) assay. Immunoglobulin M (IgM) antibodies were observed for 6 of 13 patients (46%) without a corresponding development of IgG, and for 3 of 10 patients (30%) at least 1 year post-onset. However, recent infection with a spotted fever group rickettsiae could not be confirmed for any patient, based on a lack of rising antibody titers in properly timed acute and convalescent serologic specimens, and negative findings by polymerase chain reaction testing.

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Ehrlichiosis is a tick-borne disease that ranges in severity from asymptomatic infection to fatal sepsis. Ehrlichiosis acquired from transfusion of blood products has not been documented in the literature to date. A case of Ehrlichia ewingii infection likely transmitted by transfusion of leukoreduced platelets is described, and public health implications are discussed.

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Several spotted fever group rickettsiae (SFGR) previously believed to be nonpathogenic are speculated to contribute to infections commonly misdiagnosed as Rocky Mountain spotted fever (RMSF) in the United States, but confirmation is difficult in cases with mild or absent systemic symptoms. We report an afebrile rash illness occurring in a patient 4 days after being bitten by a Rickettsia montanensis-positive Dermacentor variabilis tick. The patient's serological profile was consistent with confirmed SFGR infection.

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Recrudescent Rickettsia prowazekii infection, also known as Brill-Zinsser disease, can manifest decades after untreated primary infection but is rare in contemporary settings. We report the first known case of Brill-Zinsser disease in a patient originally infected with a zoonotic strain of R. prowazekii acquired from flying squirrels.

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Q fever was diagnosed in a previously healthy man who had recently traveled to the East Coast of Australia. The patient experienced fever and headache accompanied by lymphopenia and elevated liver enzymes but not pneumonia. He had no known direct exposures to animals, exhibited IgM and IgG seroconversion to phase II antigen of Coxiella burnetii and IgM only to phase I antigen, and responded to doxycycline treatment.

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Background: Rocky Mountain spotted fever is a life-threatening, tick-borne disease caused by Rickettsia rickettsii. This disease is rarely reported in Arizona, and the principal vectors, Dermacentor species ticks, are uncommon in the state. From 2002 through 2004, a focus of Rocky Mountain spotted fever was investigated in rural eastern Arizona.

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Serum samples from people exposed to sheep at a research facility were evaluated by a commercial laboratory and resulted in an overall Coxiella burnetii seroprevalence of 75%. We interviewed individuals to determine exposure history and compatible illness, and retested their sera. Analysis indicated that the commercial laboratory was misinterpreting its results; when corrected, the seroprevalence dropped to 27%.

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The increasing popularity of foreign travel and ecotourism places travelers at increased risk for certain tick-borne diseases. From 1999 through 2002, 31 cases of imported spotted fever-group rickettsioses (SFGR) in United States residents reporting travel to Africa were confirmed by laboratory testing at the Centers for Disease Control and Prevention. Nineteen patients (61%) reported visiting South Africa prior to illness onset.

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Background: Rickettsialpox is a self-limited febrile illness with skin lesions that may be mistaken for signs of potentially more serious diseases, such as cutaneous anthrax or chickenpox. The cluster of cutaneous anthrax cases from bioterrorism in October 2001 likely heightened awareness of and concern for cutaneous eschars.

Objectives: To apply an immunohistochemical technique on paraffin-embedded skin biopsy specimens for diagnosing rickettsialpox, and to compare the reported incidence of rickettsialpox before, during, and after the cluster of cutaneous anthrax cases.

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Rickettsialpox, a spotted fever rickettsiosis, was first identified in New York City (NYC) in 1946. During the next five years, approximately 540 additional cases were identified in NYC. However, during the subsequent five decades, rickettsialpox received relatively little attention from clinicians and public health professionals, and reporting of the disease diminished markedly.

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