Adding yeast extract to culture medium enhances replication of the avian coronavirus infectious bronchitis virus in chicken embryo kidney cells.

Infectious bronchitis virus (IBV), an avian coronavirus, can be isolated and cultured in tracheal organ cultures (TOCs), embryonated eggs and cell cultures, the first two of which are commonly used for viral isolation. Previous studies have suggested that foetal bovine serum (FBS) can inhibit coronavirus replication in cell cultures. In this study, the replication of IBV in chicken embryo kidney (CEK) cell cultures and the Leghorn hepatocellular carcinoma (LMH) cell line was assessed using two different cell culture media containing FBS or yeast extract (YE) and two different IBV strains. The highest concentrations of viral genomes were observed when the cell culture medium (CEK) contained YE. Similar results were observed in LMH cells. Examination of the infectivity by titration demonstrated that the cell lysate from CEK cell cultures in a medium including YE contained a higher median embryo infectious dose than that from CEK cell cultures in a medium containing FBS. These results indicate that improved replication of IBV in cell cultures can be achieved by replacing FBS with YE in the cell culture medium.

Characterization of the Edge States in Colloidal Bi2Se3 Platelets.

The remarkable development of colloidal nanocrystals with controlled dimensions and surface chemistry has resulted in vast optoelectronic applications. But can they also form a platform for quantum materials, in which electronic coherence is key? Here, we use colloidal, two-dimensional Bi2Se3 crystals, with precise and uniform thickness and finite lateral dimensions in the 100 nm range, to study the evolution of a topological insulator from three to two dimensions. For a thickness of 4-6 quintuple layers, scanning tunneling spectroscopy shows an 8 nm wide, nonscattering state encircling the platelet. We discuss the nature of this edge state with a low-energy continuum model and ab initio GW-Tight Binding theory. Our results also provide an indication of the maximum density of such states on a device.

Controlling the input: How one-year-old infants sustain visual attention.

Traditionally, the exogenous control of gaze by external saliencies and the endogenous control of gaze by knowledge and context have been viewed as competing systems, with late infancy seen as a period of strengthening top-down control over the vagaries of the input. Here we found that one-year-old infants control sustained attention through head movements that increase the visibility of the attended object. Freely moving one-year-old infants (n = 45) wore head-mounted eye trackers and head motion sensors while exploring sets of toys of the same physical size. The visual size of the objects, a well-documented salience, varied naturally with the infant's moment-to-moment posture and head movements. Sustained attention to an object was characterized by the tight control of head movements that created and then stabilized a visual size advantage for the attended object for sustained attention. The findings show collaboration between exogenous and endogenous attentional systems and suggest new hypotheses about the development of sustained visual attention.

Synergistic Role of Water and Oxygen Leads to Degradation in Formamidinium-Based Halide Perovskites.

Mixed-cation metal halide perovskites have shown remarkable progress in photovoltaic applications with high power conversion efficiencies. However, to achieve large-scale deployment of this technology, efficiencies must be complemented by long-term durability. The latter is limited by external factors, such as exposure to humidity and air, which lead to the rapid degradation of the perovskite materials and devices. In this work, we study the mechanisms causing Cs and formamidinium (FA)-based halide perovskite phase transformations and stabilization during moisture and air exposure. We use in situ X-ray scattering, X-ray photoelectron spectroscopy, and first-principles calculations to study these chemical interactions and their effects on structure. We unravel a surface reaction pathway involving the dissolution of FAI by water and iodide oxidation by oxygen, driving the Cs/FA ratio into thermodynamically unstable regions, leading to undesirable phase transformations. This work demonstrates the interplay of bulk phase transformations with surface chemical reactions, providing a detailed understanding of the degradation mechanism and strategies for designing durable and efficient perovskite materials.

Genomic diversity and natural recombination of equid gammaherpesvirus 5 isolates.

BACKGROUND: Equid gammaherpesvirus 5 (EHV5) is closely related to equid gammaherpesvirus 2 (EHV2). Detection of EHV5 is frequent in horse populations worldwide, but it is often without a clear and significant clinical impact. Infection in horses can often present as subclinical disease; however, it has been associated with respiratory disease, including equine multinodular pulmonary fibrosis (EMPF). Genetic heterogeneity within small regions of the EHV5 glycoprotein B (gB) sequences have been reported and multiple genotypes of this virus have been identified within individual horses, but full genome sequence data for these viruses is limited. The primary focus of this study was to assess the genomic diversity and natural recombination among EHV5 isolates. RESULTS: The genome size of EHV5 prototype strain and the five EHV5 isolates cultured for this study, including four isolates from the same horse, ranged from 181,929 to 183,428 base pairs (bp), with the sizes of terminal repeat regions varying from 0 to 10 bp. The nucleotide sequence identity between the six EHV5 genomes ranged from 95.5 to 99.1%, and the estimated average nucleotide diversity between isolates was 1%. Individual genes displayed varying levels of nucleotide diversity that ranged from 0 to 19%. The analysis of nonsynonymous substitution (Ka > 0.025) revealed high diversity in eight genes. Genome analysis using RDP4 and SplitsTree programs detected evidence of past recombination events between EHV5 isolates. CONCLUSION: Genomic diversity and recombination hotspots were identified among EHV5 strains. Recombination can drive genetic diversity, particularly in viruses that have a low rate of nucleotide substitutions. Therefore, the results from this study suggest that recombination is an important contributing factor to EHV5 genomic diversity. The findings from this study provide additional insights into the genetic heterogeneity of the EHV5 genome.

Arthroscopic Anterior Shoulder Capsular Reconstruction Using Human Acellular Dermal Graft in Conjunction With Anatomic Glenoid Reconstruction.

Capsular insufficiency of the shoulder associated with glenoid bone loss poses a major challenge to orthopaedic surgeons in the management of recurrent anterior instability. Multiple surgical techniques have been described in the literature with varying rates of success, and the majority of these are open techniques. We present a complete arthroscopic technique for anterior capsular reconstruction using acellular human dermal allograft patch in conjunction to an anatomic glenoid reconstruction using a distal tibial allograft in the lateral decubitus position. If the capsular insufficiency is determined irreparable after glenoid reconstruction, the acellular human dermal graft patch is prepared, inserted into the shoulder joint, and appropriately fixed using suture anchors on both glenoid and humerus, all through arthroscopic portals.

Interface Reconstruction from Ruddlesden-Popper Structures Impacts Stability in Lead Halide Perovskite Solar Cells.

The impact of the bulky-cation-modified interfaces on halide perovskite solar cell stability is underexplored. In this work, the thermal instability of the bulky-cation interface layers used in the state-of-the-art solar cells is demonstrated. X-ray photoelectron spectroscopy and synchrotron-based grazing-incidence X-ray scattering measurements reveal significant changes in the chemical composition and structure at the surface of these films that occur under thermal stress. The changes impact charge-carrier dynamics and device operation, as shown in transient photoluminescence, excitation correlation spectroscopy, and solar cells. The type of cation used for surface treatment affects the extent of these changes, where long carbon chains provide more stable interfaces. These results highlight that prolonged annealing of the treated interfaces is critical to enable reliable reporting of performances and to drive the selection of different bulky cations.

Whole genome sequence analysis of equid gammaherpesvirus -2 field isolates reveals high levels of genomic diversity and recombination.

BACKGROUND: Equid gammaherpesvirus 2 (EHV2) is a gammaherpesvirus with a widespread distribution in horse populations globally. Although its pathogenic significance can be unclear in most cases of infection, EHV2 infection can cause upper respiratory tract disease in foals. Co-infection of different strains of EHV2 in an individual horse is common. Small regions of the EHV2 genome have shown considerable genetic heterogeneity. This could suggest genomic recombination between different strains of EHV2, similar to the extensive recombination networks that have been demonstrated for some alphaherpesviruses. This study examined natural recombination and genome diversity of EHV2 field isolates. RESULTS: Whole genome sequencing analysis of 18 EHV2 isolates, along with analysis of two publicly available EHV2 genomes, revealed variation in genomes sizes (from 173.7 to 184.8 kbp), guanine plus cytosine content (from 56.7 to 57.8%) and the size of the terminal repeat regions (from 17,196 to 17,551 bp). The nucleotide sequence identity between the genomes ranged from 86.2 to 99.7%. The estimated average inter-strain nucleotide diversity between the 20 EHV2 genomes was 2.9%. Individual gene sequences showed varying levels of nucleotide diversity and ranged between 0 and 38.1%. The ratio of nonsynonymous substitutions, Ka, to synonymous substitutions, Ks, (Ka/Ks) suggests that over 50% of EHV2 genes are undergoing diversifying selection. Recombination analyses of the 20 EHV2 genome sequences using the recombination detection program (RDP4) and SplitsTree revealed evidence of viral recombination. CONCLUSIONS: Analysis of the 18 new EHV2 genomes alongside the 2 previously sequenced genomes revealed a high degree of genetic diversity and extensive recombination networks. Herpesvirus genome diversification and virus evolution can be driven by recombination, and our findings are consistent with recombination being a key mechanism by which EHV2 genomes may vary and evolve.

State of ex situ conservation of landrace groups of 25 major crops.

Crop landraces have unique local agroecological and societal functions and offer important genetic resources for plant breeding. Recognition of the value of landrace diversity and concern about its erosion on farms have led to sustained efforts to establish ex situ collections worldwide. The degree to which these efforts have succeeded in conserving landraces has not been comprehensively assessed. Here we modelled the potential distributions of eco-geographically distinguishable groups of landraces of 25 cereal, pulse and starchy root/tuber/fruit crops within their geographic regions of diversity. We then analysed the extent to which these landrace groups are represented in genebank collections, using geographic and ecological coverage metrics as a proxy for genetic diversity. We find that ex situ conservation of landrace groups is currently moderately comprehensive on average, with substantial variation among crops; a mean of 63% ± 12.6% of distributions is currently represented in genebanks. Breadfruit, bananas and plantains, lentils, common beans, chickpeas, barley and bread wheat landrace groups are among the most fully represented, whereas the largest conservation gaps persist for pearl millet, yams, finger millet, groundnut, potatoes and peas. Geographic regions prioritized for further collection of landrace groups for ex situ conservation include South Asia, the Mediterranean and West Asia, Mesoamerica, sub-Saharan Africa, the Andean mountains of South America and Central to East Asia. With further progress to fill these gaps, a high degree of representation of landrace group diversity in genebanks is feasible globally, thus fulfilling international targets for their ex situ conservation.

Formation of a Secondary Phase in Thermally Evaporated MAPbI3 and Its Effects on Solar Cell Performance.

Thermal evaporation is a promising deposition technique to scale up perovskite solar cells (PSCs) to large areas, but the lack of understanding of the mechanisms that lead to high-quality evaporated methylammonium lead triiodide (MAPbI3) films gives rise to devices with efficiencies lower than those obtained by spin coating. This work investigates the crystalline properties of MAPbI3 deposited by the thermal coevaporation of PbI2 and MAI, where the MAI evaporation rate is controlled by setting different temperatures for the MAI source and the PbI2 deposition rate is controlled with a quartz crystal microbalance (QCM). Using grazing incident wide-angle X-ray scattering (GIWAXS) and X-ray diffraction (XRD), we identify the formation of a secondary orthorhombic phase (with a Pnma space group) that appears at MAI source temperatures below 155 °C. With synchrotron-based X-ray fluorescence (XRF) microscopy, we show that the changes in crystalline phases are not necessarily due to changes in stoichiometry. The films show a stochiometric composition when the MAI source is heated between 140 to 155 °C, and the samples become slightly MAI rich at 165 °C. Increasing the MAI temperature beyond 165 °C introduces an excess of MAI in the film, which promotes the formation of films with low crystallinity that contain low-dimensional perovskites. When they are incorporated in solar cells, the films deposited at 165 °C result in the champion power conversion efficiency, although the presence of a small amount of low-dimensional perovskite may lead to a lower open-circuit voltage. We hypothesize that the formation of secondary phases in evaporated films limits the performance of PSCs and that their formation can be suppressed by controlling the MAI source temperature, bringing the film toward a phase-pure tetragonal structure. Control of the phases during perovskite evaporation is therefore crucial to obtain high-performance solar cells.

Arthroscopic Anatomic Glenoid Reconstruction With Distal Tibial Allograft and Hybrid Fixation.

Glenoid grafting is the standard surgical treatment for recurrent shoulder instability with significant glenoid bone loss. Arthroscopic anatomic glenoid reconstruction using a distal tibial allograft for anatomic glenoid reconstruction has recently been gaining attention. This article describes the use of a hybrid graft fixation technique with 1 suture-EndoButton device and 1 compression screw in arthroscopic anatomic glenoid reconstruction using distal tibial allograft.

Alterações dimensionais de maxilas portadoras de caninos impactados / Dimensional changes of maxillas with impacted canines

O objetivo do estudo foi avaliar medidas do arco superior realizadas em imagens por Tomografia Computadorizada de Feixe Cônico (TCFC) de pacientes com caninos impactados localizados por vestibular e palatino. Método: A amostra consistiu de imagens axiais de TCFC de 63 pacientes de ambos os sexos (44 do sexo feminino e 19 do masculino) com média de idade de 17,8 anos. Empregou-se software OnDemand® 3D para obter as medidas de distância intermolar, perímetro e comprimento maxilar. Inicialmente, foi realizada análise descritiva e exploratória dos dados. Foi aplicado teste t de Student para comparar os dois grupos com canino impactado uni e bilateralmente e análise de variância (ANOVA) para comparar os grupos, quanto à posição do canino impactado, por vestibular ou palatino. A reprodutibilidade entre as medidas foi avaliada pelo coeficiente de correlação intraclasse (ICC), considerado o nível de significância de 5% Resultados: Pôde-se verificar que do total de voluntários, 39 indivíduos apresentavam caninos impactados unilateralmente e 24 bilateralmente. Desses, 26 apresentavam-se na posição vestibular e 37 na posição palatina. Observou-se que a distância intermolares foi significativamente menor no grupo com canino impactado bilateralmente (p<0,05), o perímetro e o comprimento do arco maxilar não diferiram significativamente entre os pacientes com caninos impactados unilateral ou bilateralmente (p>0,05). Porém esses parâmetros se apresentaram significativamente menores (p<0,05) nos pacientes com canino impactados na posição palatina. Conclusões: Maxilas com caninos impactados bilateralmente apresentam distância intermolar menor e caninos impactados por palatino estão presentes em maxilas com o menor perímetro de arco.(AU)

Objective: The purpose of the study was to evaluate measurements of the upper arch performed by Cone Beam Computed Tomography (CBCT) images of patients with impacted canines located in the vestibular and palatal areas. Method: The sample consisted of axial CBCT images of 63 patients of both genders (44 female and 19 male) with a mean age of 17.8 years. OnDemand® 3D software was used to obtain the measurements of intermolar distance, perimeter and maxillary length. Initially, descriptive and exploratory data analysis was performed. Student t test was applied to compare the two groups with unilaterally and bilaterally impacted canines, and analysis of variance (ANOVA) was used to compare the groups regarding the position the impacted canine, either vestibular or palatal. Reproducibility between measurements was evaluated by the intraclass correlation coefficient (ICC), considering the level of significance of 5%. Results: It was possible to verify that of the total number of volunteers, 39 individuals had unilaterally and 24 bilaterally impacted canines. Of these, 26 were in the vestibular position and 37 in the palatal position. It was observed that the intermolar distance was significantly smaller in the group with bilaterally impacted canines (p<0.05), the perimeter and maxillary arch length did not differ significantly among patients with unilaterally or bilaterally impacted canines (p>0.05). However, these parameters were significantly lower (p<0.05) in patients with impacted canines in the palatal position. Conclusions: Maxillas with bilaterally impacted canines present smaller intermolar distance, and palatal canines impacted are present in maxillary with the smallest arch perimeter.(AU)

Superinfection and recombination of infectious laryngotracheitis virus vaccines in the natural host.

Infectious laryngotracheitis virus (ILTV, Gallid alphaherpesvirus 1) causes severe respiratory disease in chickens and has a major impact on the poultry industry worldwide. Live attenuated vaccines are widely available and are administered early in the life of commercial birds, often followed by one or more rounds of revaccination, generating conditions that can favour recombination between vaccines. Better understanding of the factors that contribute to the generation of recombinant ILTVs will inform the safer use of live attenuated herpesvirus vaccines. This study aimed to examine the parameters of infection that allow superinfection and may enable the generation of recombinant progeny in the natural host. In this study, 120 specific-pathogen free (SPF) chickens in 8 groups were inoculated with two genetically distinct live-attenuated ILTV vaccine strains with 1-4 days interval between the first and second vaccinations. After inoculation, viral genomes were detected in tracheal swabs in all groups, with lowest copies detected in swabs collected from the groups where the interval between inoculations was 4 days. Superinfection of the host was defined as the detection of the virus that was inoculated last, and this was detected in tracheal swabs from all groups. Virus could be isolated from swabs at a limited number of timepoints, and these further illustrated superinfection of the birds as recombinant viruses were detected among the progeny. This study has demonstrated superinfection at host level and shows recombination events occur under a very broad range of infection conditions. The occurrence of superinfection after unsynchronised infection with multiple viruses, and subsequent genomic recombination, highlight the importance of using only one type of vaccine per flock as the most effective way to limit recombination.

Serological evidence for the presence of wobbly possum disease virus in Australia.

Wobbly possum disease virus (WPDV) is an arterivirus that was originally identified in common brushtail possums (Trichosurus vulpecula) in New Zealand, where it causes severe neurological disease. In this study, serum samples (n = 188) from Australian common brushtail, mountain brushtail (Trichosurus cunninghami) and common ringtail (Pseudocheirus peregrinus) possums were tested for antibodies to WPDV using ELISA. Antibodies to WPDV were detected in possums from all three species that were sampled in the states of Victoria and South Australia. Overall, 16% (30/188; 95% CI 11.0-22.0) of possums were seropositive for WPDV and 11.7% (22/188; 95% CI 7.5-17.2) were equivocal. The frequency of WPDV antibody detection was the highest in possums from the two brushtail species. This is the first reported serological evidence of infection with WPDV, or an antigenically similar virus, in Australian possums, and the first study to find antibodies in species other than common brushtail possums. Attempts to detect viral RNA in spleens by PCR were unsuccessful. Further research is needed to characterise the virus in Australian possums and to determine its impact on the ecology of Australian marsupials.

Latency characteristics in specific pathogen-free chickens 21 and 35 days after intra-tracheal inoculation with vaccine or field strains of infectious laryngotracheitis virus.

Latency is an important feature of infectious laryngotracheitis virus (ILTV) yet is poorly understood. This study aimed to compare latency characteristics of vaccine (SA2) and field (CL9) strains of ILTV, establish an in vitro reactivation system and examine ILTV infection in peripheral blood mononuclear cells (PBMC) in specific pathogen-free chickens. Birds were inoculated with SA2 or CL9 ILTV and then bled and culled at 21 or 35 days post-inoculation (dpi). Swabs (conjunctiva, palatine cleft, trachea) and trigeminal ganglia (TG) were examined for ILTV DNA using PCR. Half of the TG, trachea and PBMC were co-cultivated with cell monolayers to assess in vitro reactivation of ILTV infection. ILTV DNA was detected in the trachea of approximately 50% of ILTV-inoculated birds at both timepoints. At 21 dpi, ILTV was detected in the TG only in 29% and 17% of CL9- and SA2-infected birds, respectively. At 35 dpi, ILTV was detected in the TG only in 30% and 10% of CL9- and SA2-infected birds, respectively. Tracheal organ co-cultures from 30% and 70% of CL9- and SA2-infected birds, respectively, were negative for ILTV DNA at cull but yielded quantifiable DNA within 6 days post-explant (dpe). TG co-cultivation from 30% and 40% of CL9-and SA2-infected birds, respectively, had detectable ILTV DNA within 6 dpe. Latency characteristics did not substantially vary based on the strain of virus inoculated or between sampling timepoints. These results advance our understanding of ILTV latency and reactivation. RESEARCH HIGHLIGHTS Following inoculation, latent ILTV infection was detected in a large proportion of chickens, irrespective of whether a field or vaccine strain was inoculated. In vitro reactivation of latent ILTV was readily detected in tracheal and trigeminal ganglia co-cultures using PCR. ILTV latency observed in SPF chickens at 21 days post-infection was not substantially different to 35 days post-infection.

Development and Performance of Dengue Diagnostic Clinical Algorithms in Colombia.

Diagnosing dengue in endemic areas remains problematic because of the low specificity of the symptoms and lack of accurate diagnostic tests. This study aimed to develop and prospectively validate, under routine care, dengue diagnostic clinical algorithms. The study was carried out in two phases. First, diagnostic algorithms were developed using a database of 1,130 dengue and 918 non-dengue patients, expert opinion, and literature review. Algorithms with > 70% sensitivity were prospectively validated in a single-group quasi-experimental trial with an adaptive Bayesian design. In the first phase, the algorithms that were developed with the continuous Bayes formula and included leukocytes and platelet counts, in addition to selected signs and symptoms, showed the highest sensitivities (> 80%). In the second phase, the algorithms were applied on admission to 1,039 consecutive febrile subjects in three endemic areas in Colombia of whom 25 were laboratory-confirmed dengue, 307 non-dengue, 514 probable dengue, and 193 undetermined. Including parameters of the hemogram consistently improved specificity without affecting sensitivity. In the final analysis, considering only confirmed dengue and non-dengue cases, an algorithm with a sensitivity and specificity of 65.4% (95% credibility interval 50-83) and 40.1% (34.7-45.7) was identified. All tested algorithms had likelihood ratios close to 1, and hence, they are not useful to confirm or rule out dengue in endemic areas. The findings support the use of hemograms to aid dengue diagnosis and highlight the challenges of clinical diagnosis of dengue.

Pathogenesis and tissue tropism of natural field recombinants of infectious laryngotracheitis virus.

Infectious laryngotracheitis virus (ILTV) is an economically significant respiratory pathogen of poultry. Novel recombinant strains of ILTV have emerged in Australia during the last decade and currently class 9 (CL9) and class 10 (CL10) ILTV are the most prevalent circulating strains. This study conducted a comprehensive investigation of the pathogenesis of these two viral strains. Commercial broiler and specific pathogen free (SPF) chickens were inoculated with varying doses of CL9 or CL10 ILTV and subsequently evaluated for clinical and pathological signs of infection. While no difference in the levels of acute viral replication were observed across the different challenge doses, the severity of clinical signs, tracheal pathology and mortality were dose dependent. Both strains of virus persisted in the respiratory tract for up to 14 days post inoculation (dpi) and could be detected in the lung and feathers with sporadic detection in the liver, spleen or bursa. Given the prevalence of CL9 and CL10 in Australian poultry flocks, this study provides an important foundation for the development of diagnostic and therapeutic approaches for the detection and prevention of ILTV.

Development and application of a combined molecular and tissue culture-based approach to detect latent infectious laryngotracheitis virus (ILTV) in chickens.

Infectious laryngotracheitis virus (ILTV) causes severe respiratory disease in chickens. ILTV can establish latency and reactivate later in life, but there have been few investigations of ILTV latency. This study aimed to contribute to the methodologies available to detect latent ILTV. A nested PCR was developed which was more sensitive than three other molecular methods investigated in this study. This nested PCR was then used in conjunction with in vitro reactivation culture methods that were optimized and applied to trigeminal ganglia (TG) and tracheal samples from ILTV-vaccinated commercial layer birds (n = 30). ILTV DNA was detected by nested PCR in the upper respiratory tract (URT) or eye of 22 birds. Of the remaining 8 birds, ILTV could be detected by co-culture in TG of 5 birds, with reactivated virus mostly detected 6 days post-explant (dpe). ILTV was also detected in tracheal cultures by 6 dpe. In the ILTV-positive URT samples, the virus could be characterised as vaccine strains SA2 (n = 9) or A20 (n = 5). This study provides evidence for reactivation and shedding of vaccine ILTV in commercial layer birds. Moreover, this study produced a molecular and in-vitro culture method to detect latent viral infection.

Development of clinical algorithms for the diagnosis of dengue in Colombia / Desarrollo de algoritmos clínicos para el diagnóstico del dengue en Colombia

Introduction: Due to the increase in dengue incidence and mortality, its diagnosis is relevant for endemic countries. Clinical classifications and laboratory tests have a variable performance in clinical practice with a sensitivity level between 45% and 98%, and a specificity level between 4% and 98% partly due to the variety of contexts where they are applied. Objective: To develop clinical algorithms for the diagnosis of dengue in the Colombian context. Materials and methods: A cross-sectional study was conducted based on secondary sources. We constructed clinical diagnostic algorithms of dengue based on Bayesian methods combining symptoms, signs, and blood count parameters, and then we compared them in terms of diagnostic accuracy with gold standard tests. In addition, an external validation of the algorithm with greater accuracy and sensibility was performed comparing it with the WHO-1997 and the WHO-2009 clinical classifications, the Colombian guide for 2010, and the diagnostic scale recommended by the Ministerio de Salud y Protección Social of Colombia for 2013. Results: Four algorithms were generated, two for signs and symptoms, and two that included leukocytes (≤4,500/mm3) and/or platelets (≤160,000/mm3) counts. The most accurate algorithm included blood count parameters with a sensitivity of 76.5% (95%CI: 71.9-80.5) and a specificity of 46.0% (95%CI: 37.6-54.7). In the external validation we found a sensitivity of 11.1% (95%CI: 4.9-20.7) and a specificity of 91.9% (95%CI: 87.5-93.9). The scale of the Ministerio de Salud had a sensitivity of 76.4% (95%CI: 64.9-85.6) and a specificity of 38.0% (95%CI: 32.8-43.4). Conclusion: The inclusion of blood count parameters improved the sensitivity of diagnostics algorithms based on signs and symptoms. Clinical diagnosis of dengue remains a challenge for health research.

Introducción. Dado el aumento de la incidencia y la mortalidad por dengue, su diagnóstico es relevante para los países endémicos. Las clasificaciones clínicas y las pruebas de laboratorio existentes tienen un desempeño variable en la práctica clínica, pues su sensibilidad fluctúa entre 45 y 98 %, y su especificidad, entre 4 y 98 %, lo cual se debe, en parte, a la diversidad de contextos en los que se utilizan. Objetivo. Desarrollar algoritmos clínicos para el diagnóstico del dengue en el contexto colombiano. Materiales y métodos. Se hizo un estudio transversal a partir de fuentes secundarias. Se construyeron algoritmos clínicos de diagnóstico del dengue con base en métodos bayesianos que combinaron síntomas, signos y parámetros del hemograma, y se comparó su exactitud diagnóstica con la de las pruebas de referencia. Se hizo una validación externa del algoritmo de mayor exactitud y sensibilidad, comparándolo con la clasificación clínica de la Organización Mundial de la Salud de 1997 y la del 2009, con la guía colombiana del 2010 y con la escala diagnóstica propuesta por el Ministerio de Salud y Protección Social de Colombia en el 2013. Resultados. Se generaron cuatro algoritmos, dos de signos y síntomas y dos que incluyeron el conteo de leucocitos (≤4.500/mm3) o de plaquetas (≤60.000/mm3). El algoritmo de mayor exactitud incluyó los parámetros del hemograma, con una sensibilidad de 76,5 % (IC95% 71,9-80,5) y una especificidad de 46,0 % (IC95% 37,6-54,7). En la validación externa, la sensibilidad fue de 11,1 % (IC95% 4,9-20,7) y la especificidad fue de 91,9 % (IC95% 87,5-93,9). La escala del Ministerio tuvo una sensibilidad de 76,4 % (IC95% 64,9-85,6) y una especificidad de 38,0 % (IC95% 32,8-43,4). Conclusión. La inclusión de los parámetros del hemograma mejoró la sensibilidad de los algoritmos de diagnóstico basados en los signos y los síntomas. Sin embargo, el diagnóstico clínico del dengue sigue siendo un reto para la investigación en salud.

Attenuated infectious laryngotracheitis virus vaccines differ in their capacity to establish latency in the trigeminal ganglia of specific pathogen free chickens following eye drop inoculation.

Infectious laryngotracheitis (ILT) is a respiratory disease that affects chickens. It is caused by the alphaherpesvirus, infectious laryngotracheitis virus (ILTV). This virus undergoes lytic replication in the epithelial cells of the trachea and upper respiratory tract (URT) and establishes latent infection in the trigeminal ganglia (TG) and trachea. Live attenuated vaccines are widely used to control ILT. At least one of these vaccines can establish latent infections in chickens, but this has not been demonstrated for all vaccines. The aim of the current study was to determine the capacity of three commercially available vaccines (SA2, A20 and Serva) and a glycoprotein G deletion mutant vaccine candidate (ΔgG ILTV) to establish latent infection in the TG of specific pathogen free (SPF) chickens. Five groups of 7-day-old SPF chickens were eye-drop vaccinated with either one of the vaccine strains or mock-vaccinated with sterile media and followed until 20 or 21 days post-vaccination (dpv). ILTV DNA was detected at 20-21 dpv in the TG of 23/40 (57.5%) vaccinated SPF chickens (SA2 = 10/10; A20 = 6/10; Serva = 3/10; ΔgG = 4/10) by PCR, but virus could not be reactivated from TG co-cultivated with primary chicken embryo kidney cells. In the birds from which ILTV DNA was detected in the TG, ILTV DNA could not be detected in the URT or trachea of 3 birds in each of the SA2, A20 and Serva vaccinated groups, and in 4 birds in the ΔgG vaccinated group, indicating that these birds were latently infected in the absence of active lytic replication and virus shedding. Results from this study demonstrate the capacity of commercial ILTV vaccines to establish latent infections and underline their importance in the epidemiology of this disease.