1,721,174 research outputs found
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Development, Validation, and Cost Effectiveness of Clinical Prediction Rules for Group A Beta Hemolytic Streptococcal Pharyngitis In Children From Lower and Upper Middle Income Countries
Get PDFBackground: An estimated 3% of untreated group A beta hemolytic streptococcal (GABHS) pharyngitis can lead to rheumatic fever (RF), resulting in rheumatic heart disease (RHD) and other serious nonsuppurative sequelae of infection. Prevalence of disease is disproportionate with the greatest burden among children and adolescents of developing countries; an estimated 95% of RF and 79% of RHD cases are from low income countries. Accurate diagnosis and prompt antibiotic treatment of GABHS pharyngitis is a simple and effective strategy for primary prevention of RF and RHD. Accurate diagnosis is difficult without laboratory testing due to similarities in signs and symptoms with other causes of pharyngitis.Due to financial constraints, laboratory capabilities are often limited, forcing many physicians in low and middle income countries (LMICs) to either prescribe antibiotics indiscriminately or rely on clinical prediction rules (CPRs). CPRs provide a practical alternative for diagnosis in the absence of laboratory testing. However, few CPRs have been derived specifically for LMICs. Studies have shown that CPRs can be cost effective in hospital settings, but few have been conducted for children from LMICs. Methods: Children 2-12 years of age presenting with complaint of sore throat were enrolled in four urban university pediatric outpatient clinics from September 2001 to August 2005 in Rio de Janeiro, Brazil, Cairo, Egypt; Riga Latvia and Zagreb, Croatia. The diagnostic component of the study (Chapters 4-5) consisted of generating CPRs for the 1,993 children enrolled in the study. It also consisted of external validation of a) published CPRs from the literature, and b) study developed CPRs. The cost effectiveness analysis component of the study (Chapter 6) assessed the cost effectiveness of the CPR developed for Egypt versus five alternative diagnostic and management strategies.Summary: The dissertation consists of findings from three papers (Chapters 4-6). In paper 1 (Chapter 4), five different CPRs were developed for use in Egypt, Brazil, Latvia, Croatia, and the combined study population. In paper 2 (Chapter 5), external validation of published and study CPRs suggested country specific CPRs were better in the population for which they were developed. In paper 3 (Chapter 6), Culture Only was the most cost effective strategy at baseline estimates; however, the Egypt CRP was cost effective when sensitivity and specificity were at or above 88%
Zika virus infection in Nicaraguan households
Get PDFZika virus (ZIKV) infection recently caused major epidemics in the Americas and is linked to congenital birth defects and Guillain-Barré Syndrome. A pilot study of ZIKV infection in Nicaraguan households was conducted from August 31 to October 21, 2016, in Managua, Nicaragua. We enrolled 33 laboratory-confirmed Zika index cases and their household members (109 contacts) and followed them on days 3–4, 6–7, 9–10, and 21, collecting serum/plasma, urine, and saliva specimens along with clinical, demographic, and socio-economic status information. Collected samples were processed by rRT-PCR to determine viral load (VL) and duration of detectable ZIKV RNA in human bodily fluids. At enrollment, 11 (10%) contacts were ZIKV rRT-PCR-positive and 23 (21%) were positive by IgM antibodies; 3 incident cases were detected during the study period. Twenty of 33 (61%) index households had contacts with ZIKV infection, with an average of 1.9 (range 1–6) positive contacts per household, and in 60% of these households, ≥50% of the members were positive for ZIKV infection. Analysis of clinical information allowed us to estimate the symptomatic to asymptomatic (S:A) ratio of 14:23 (1:1.6) among the contacts, finding 62% of the infections to be asymptomatic. The maximum number of days during which ZIKV RNA was detected was 7 days post-symptom onset in saliva and serum/plasma and 22 days in urine. Overall, VL levels in serum/plasma, saliva, and urine specimens were comparable, with means of 5.6, 5.3 and 4.5 log10 copies/ml respectively, with serum attaining the highest VL peak at 8.1 log10 copies/ml. Detecting ZIKV RNA in saliva over a similar time-period and level as in serum/plasma indicates that saliva could potentially serve as a more accessible diagnostic sample. Finding the majority of infections to be asymptomatic emphasizes the importance of silent ZIKV transmission and helps inform public health interventions in the region and globally.</div
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Optimization of a Novel Non-invasive Oral Sampling Technique for Zoonotic Pathogen Surveillance in Nonhuman Primates.
Get PDFFree-ranging nonhuman primates are frequent sources of zoonotic pathogens due to their physiologic similarity and in many tropical regions, close contact with humans. Many high-risk disease transmission interfaces have not been monitored for zoonotic pathogens due to difficulties inherent to invasive sampling of free-ranging wildlife. Non-invasive surveillance of nonhuman primates for pathogens with high potential for spillover into humans is therefore critical for understanding disease ecology of existing zoonotic pathogen burdens and identifying communities where zoonotic diseases are likely to emerge in the future. We developed a non-invasive oral sampling technique using ropes distributed to nonhuman primates to target viruses shed in the oral cavity, which through bite wounds and discarded food, could be transmitted to people. Optimization was performed by testing paired rope and oral swabs from laboratory colony rhesus macaques for rhesus cytomegalovirus (RhCMV) and simian foamy virus (SFV) and implementing the technique with free-ranging terrestrial and arboreal nonhuman primate species in Uganda and Nepal. Both ubiquitous DNA and RNA viruses, RhCMV and SFV, were detected in oral samples collected from ropes distributed to laboratory colony macaques and SFV was detected in free-ranging macaques and olive baboons. Our study describes a technique that can be used for disease surveillance in free-ranging nonhuman primates and, potentially, other wildlife species when invasive sampling techniques may not be feasible
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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Controlling emerging zoonoses at the animal-human interface
Get PDFFor many emerging or re-emerging pathogens, cases in humans arise from a mixture of introductions (via zoonotic spillover from animal reservoirs or geographic spillover from endemic regions) and secondary human-to-human transmission. Interventions aiming to reduce incidence of these infections can be focused on preventing spillover or reducing human-to-human transmission, or sometimes both at once, and typically are governed by resource constraints that require policymakers to make choices. Despite increasing emphasis on using mathematical models to inform disease control policies, little attention has been paid to guiding rational disease control at the animal-human interface. In this thesis, I introduce a modeling framework to analyze the impacts of different disease control policies, focusing on pathogens exhibiting subcritical transmission among humans. We quantify the relative effectiveness of measures to reduce spillover (e.g. reducing contact with animal hosts), human-to-human transmission (e.g. case isolation), or both at once (e.g. vaccination), across a range of epidemiological contexts. This analysis provides guidelines for choosing which mode of control to prioritize in different epidemiological scenarios and considering different levels of resource and relative costs. We contextualize our analysis with current zoonotic pathogens and other subcritical pathogens, such as post-elimination measles, and control policies that have been applied. This work provides a model-based, theoretical foundation to understand and guide policy for subcritical zoonoses, integrating across disciplinary and species boundaries in a manner consistent with One Health principles
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A Novel Radiologic Finding to Predict Ophthalmic Abnormalities in Children with Congenital Zika
Get PDFIn northeastern Brazil, following the Zika virus (ZIKV) outbreak, we investigated whether a specific radiologic finding was associated with sight-threatening abnormalities in children with Congenital Zika Syndrome (CZS). Cohort Study from March 2016 to December 2018, in Paraiba, Brazil. We evaluated children born to mothers with laboratory confirmed ZIKV infection during pregnancy (ZIKV RT-PCR) and children born with clinical and radiologic features of CZS.A total of 102 infants were evaluated; 75 infants had both brain imaging and complete eye exams. 22% of infants had infratentorial abnormalities; microcephaly was present in 71%; all had brain calcifications. 94% of children with infratentorial abnormalities had ophthalmic abnormalities. Conversely, 28% without infratentorial abnormalities, had ophthalmic abnormalities (OR 42.0; 95%CI 5.1-342.9). The presence of Infratentorial abnormalities a significant predictor of ophthalmic abnormalities. All neonates whose mothers had ZIKV exposure at any time during pregnancy should have ophthalmologic examination
An integrated active case detection and management of skin NTDs in yaws endemic health districts in Cameroon, Côte d'Ivoire and Ghana.
Get PDFBACKGROUND: Integrated approaches to mapping skin Neglected Tropical Diseases (NTDs) may be cost-effective way to guide decisions on resource mobilization. Pilot studies have been carried out, but large-scale data covering multiple countries endemic for skin NTDs are lacking. Within the LAMP4YAWS project, we collected integrated data on the burden of multiple skin NTDs. METHODS: From March 2021 to March 2023, integrated case searches for yaws alongside other skin conditions were performed in endemic health districts of yaws in Cameroon, Côte d'Ivoire, and Ghana. Integrated activities included training, social mobilization and active case detection. Initial screening involved a brief clinical examination of participants to determine if any skin conditions were suspected. Cases of skin NTDs were then referred to a health facility for appropriate management. RESULTS: Overall 61,080 individuals screened, 11,387 (18.6%) had skin lesions. The majority of individuals (>90%) examined were children aged 15 years old and under. The proportion of serologically confirmed yaws cases was 8.6% (18/210) in Cameroon, 6.8% (84/1232) in Côte d'Ivoire, and 26.8% (440/1643) in Ghana. Other skin conditions based on clinical examination included: scabies, Buruli ulcer, leprosy, lymphatic filariasis (lymphoedema and hydrocele), tungiasis, and fungal infections. The most common conditions were scabies and superficial fungal infections. In Cameroon, scabies and superficial fungal infections accounted for 5.1% (214/4204) and 88.7% (3730/4204) respectively, 25.2% (1285/5095) and 50.4% (2567/5095) in Côte d'Ivoire. In Ghana, 20% (419/2090) of individuals had scabies but superficial fungal infections were not routinely recorded and were reported in only 1.3% (28/2090). Other skin NTDs were less common across all three countries. CONCLUSION: This study confirms that integrated screening allows simultaneous detection of multiple skin NTDs, maximising use of scarce resources
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