Ivermectin antiviral activity against Varicellovirus bovinealpha 1: assessment of intracellular drug accumulation in virus-infected cells.

Varicellovirus bovinealpha 1 (formerly bovine alphaherpesvirus type 1, BoAHV-1) is associated with several syndromes in cattle, including respiratory disease and is one of the main agents involved in the bovine respiratory disease complex (BRDC). Its infectious cycle is characterized by latent infections with sporadic virus reactivation and transmission. Although the acute disease can be prevented by the use of vaccines, specific therapeutic measures are not available. Ivermectin (IVM) is a semi-synthetic avermectin with a broad-spectrum antiparasitic activity, which has previously shown to have potential as an antiviral drug. In this study, IVM antiviral activity against BoAHV-1 was characterized in two cell lines (MDBK [Madin Darby bovine kidney] and BT [bovine turbinate]), including the measurement of intracellular drug accumulation within virus-infected cells. IVM antiviral activity was assessed at three different drug concentrations (1.25, 2.5 and 5 µM) after incubation for 24, 48 and 72 h. Slight cytotoxicity was only observed with 5 µM IVM. Even the lowest IVM dose was able to induce a significant reduction in virus titers in both cell lines. These findings indicate that the antiviral effects of IVM were evident in our experimental model within the range of concentrations achievable through therapeutic in vivo administration. Consequently, additional in vivo trials are necessary to validate the potential utility of these results in effectively managing BoAHV-1 in infected cattle.

In vitro efficacy of ganciclovir against feline herpesvirus type 1 and assessment of ocular tolerability in healthy cats.

OBJECTIVES: Feline herpesvirus-1 (FHV-1) is a prevalent cause of ocular disease in cats and limited topical options for treatment currently exist. The first objective of this study was to confirm the efficacy of ganciclovir against FHV-1 in vitro. The second objective was to assess the safety and ocular tolerability of topically applied ganciclovir eye gel (GEG) in healthy cats. METHODS: FHV-1 was used to infect tissue culture wells covered in maximally confluent Crandall-Rees feline kidney cells prior to the addition of three molarities of ganciclovir (8.9 µM, 17.8 µM and 89 µM) before being incubated for 48 h. Ganciclovir efficacy in vitro was then assessed using standard plaque reduction assay. Commercially available GEG (0.15%) was applied q8h to one randomly chosen eye of four healthy cats for 7 days. Commercially available lubricating eye gel (LEG) was applied to the opposite eye q8h. Complete blood counts (CBCs), blood chemistry panels (CHEM) and urinalysis (UA) were performed on all cats before and after the study period. Ocular lesions were assessed daily using a standardized scheme. RESULTS: Ganciclovir led to a significant reduction in FHV-1 plaque number, area and diameter at all tested molarities in vitro. The highest molarity assessed (89 µM) caused a 100% reduction in viral plaque number. There was no significant difference in ocular lesion scores between eyes receiving GEG and LEG. Animals remained healthy throughout the study period with CBC, CHEM and UA showing no clinically significant alterations. CONCLUSIONS AND RELEVANCE: Based on the in vitro results, ganciclovir appears to be effective against FHV-1 in vitro. When applied q8h as a commercial 0.15% gel to a small group of cats with normal eyes, this medication was well tolerated. Taken together, these data suggest this medication warrants further investigation in cats with ocular disease caused by FHV-1.

Caraterización epidemiológica de varicela, en Región Sanitaria Metropolitana del Distrito Central, Honduras, 2016 / Epidemiological characterization of chickenpox, in the Metropolitan Sanitary Region of the Central District, Honduras, 2016

Se estima que más del 90 % de la población mundial susceptible ha padecido varicela antes de los 15 años. En Honduras son escasos los estudios realizados sobre esta enfermedad. Objetivo: establecer las características clínico-epidemiológicas de varicela en población afectada de la Región Sanitaria Metropolitana del Distrito Central, del 1 de enero al 31 de diciembre 2016. Material y Métodos: estudio transversal; universo de 2 885 casos reportados a la unidad de vigilancia de la Región Sanitaria Metropolitana del Distrito Central. Se estudiaron 343 casos, los cuales se seleccionaron proporcionalmente según el número de casos por establecimientos de salud de procedencia. Se creó una ficha y una base de datos en MS Excel, el análisis se hizo usando Epi Info. Resultados: la mayoría de los casos tenían menos de 12 años de edad, los grupos más afectados fueron los de 0 a 5 años, 153(44.9%) y los de 6 a 12 años, 113(33.1%), la media de edad fue de 9.2 años ± 10 años 1DE. Un tercio fue atendido a nivel hospitalario; en el Instituto Hondureño de Seguridad Social 109(31.8%), 4(1.2%) en el Hospital San Felipe y 2(0.6%) en el Hospital Escuela Universitario. La media de duración de la fiebre sin complicaciones fue 2.1 días ± 1.2 días. Uno de cada 10 casos presentó alguna complicación, entre éstas, las enfermedades respiratorias superiores (6.4%) y lesiones de piel (1.5%) y los menores de 6 años tendieron a sufrir complicaciones. 74% recibió antipiréticos/antiinflamatorios, 47.6% antihistamínicos y 25.1% antibióticos. La prescripción de antibióticos fue significativamente mayor para casos con complicaciones (OR=17.9, IC95% 7.3-44.0), al igual que analgésicos y antipiréticos (OR=2.8, IC95% 1-8.3). Conclusiones: la población más afectada fueron los niños menores de 12 años y las complicaciones se observaron en niños menores de 6 años. El uso de antibióticos y analgésicos fue mayor en casos con complicaciones. Los hallazgos del estudio apoyan la importancia de considerar la inclusión de la vacuna contra varicela en el esquema nacional de inmunizaciones...(AU)

Development of a cross-priming isothermal amplification assay based on the glycoprotein B gene for instant and rapid detection of feline herpesvirus type 1.

A cross-priming isothermal amplification (CPA) assay was developed for detection of feline herpesvirus type 1 (FHV-1). In this assay, the target fragment of the FHV-1 glycoprotein B gene is amplified rapidly by Bst DNA polymerase at a constant temperature (63 °C, 45 min), using a simple thermostat. The assay had no cross-reactions with four types of feline viruses, and the detection limit was 100 copies/µl. The positive rate of clinical samples from CPA was 100% consistent with qPCR but higher than ordinary PCR, indicating its superiority to ordinary PCR. Visualization was achieved using SYBR Green I dye.

Assessment of quantitative polymerase chain reaction for equine herpesvirus-5 in blood, nasal secretions and bronchoalveolar lavage fluid for the laboratory diagnosis of equine multinodular pulmonary fibrosis.

REASONS FOR PERFORMING STUDY: The ante mortem diagnosis of equine multinodular pulmonary fibrosis (EMPF) relies on histopathological results and polymerase chain reaction (PCR)-positive equine herpesvirus (EHV)-5 testing of lung tissue. Polymerase chain reaction detection of EHV-5 in bronchoalveolar lavage fluid (BALF) is commonly used to support a diagnosis of EMPF. However, the diagnostic power of EHV-5 testing on BALF and other biological samples such as blood and nasal secretions has yet to be shown to support a diagnosis of EMPF. OBJECTIVES: To determine the frequency of detection and the viral loads of EHV-5 by quantitative PCR (qPCR) in blood, nasal secretions and BALF from horses confirmed with EMPF, healthy horses and horses with non-EMPF pulmonary diseases. STUDY DESIGN: Prospective study. METHODS: The study population consisted of 70 adult horses divided into 4 groups based on a combination of clinical findings, cytology of BALF, imaging studies of the thoracic cavity and histopathology of pulmonary tissue: control group (n = 14), EMPF group (n = 11); inflammatory airway disease group (n = 32); and non-EMPF interstitial lung disease group (n = 13). For each horse, whole blood, nasal secretions and BALF were available for EHV-5 qPCR testing. Sensitivities, specificities and their respective 95% confidence intervals were calculated for viral loads from blood, nasal secretions and BALF. In addition, these measures were calculated for combined use of blood and nasal secretions. RESULTS: The detection of EHV-5 in BALF was strongly associated with EMPF (sensitivity 91%, specificity 98.3%). Detection of EHV-5 in blood was, independent of the viral loads, strongly associated with EMPF with a sensitivity of 91% and specificity of 83.1%. The detection of EHV-5 in nasal secretions displayed the highest sensitivity (72.7%) and specificity (83.1%) at a level of >245,890 glycoprotein B target genes/million cells to support a diagnosis of EMPF. Dually positive blood and nasal secretions at any viral loads in support of EMPF yielded a sensitivity and specificity of 90% and 89.8%, respectively. CONCLUSIONS: Although histopathological confirmation (lung biopsy) is considered the gold standard for EMPF diagnosis, results of qPCR testing of BALF or a combination of whole blood and nasal secretions should be regarded as clinically useful in support of this diagnosis. The latter testing may be relevant when dealing with horses in respiratory distress, for which invasive procedures such as BALF collection or lung biopsies may be detrimental to their health.

Amended recombinant cells (ARCs) expressing bovine IFN-gamma: an economical and highly effective adjuvant system.

Interferon-gamma (IFN-gamma) has potent immune stimulatory activity, but purifying recombinant protein is expensive, soluble cytokine delivery is inefficient, and high doses of IFN-gamma cause adverse systemic effects. We've shown, however, that chemically fixed, amended recombinant Pseudomonas fluorescens cells (ARCs), expressing soluble bovine IFN-gamma (BGI/ARCs), provide an effective production and delivery vehicle for highly active cytokine. In this report we investigate the immune enhancing activity of BGI/ARCs in the presence or absence of two other adjuvants which enhance cell recruitment and protein uptake. Adjuvant activity and immune-mediated protection was evaluated using recombinant, truncated glycoprotein-D (tgD) and a bovine herpesvirus-1 (BHV-1) disease challenge. Our initial dose-titration study showed that 100 microg of recombinant IFN-gamma in BGI/ARCs significantly increased both IgG1 and IgG2 tgD-specific antibody titres and IgG1/IgG2 ratios were significantly reduced with as little as 1.0 microg IFN-gamma. Vaccine formulation studies, using 20 microg tgD/vaccine dose and 100 microg IFN-gamma delivered in BGI/ARCs, formulated in phosphate buffered saline (PBS), induced significantly increased antibody responses, following both primary and secondary immunization, and immune-mediated protection following a BHV-1 respiratory infection. Co-formulating BGI/ARCs with either an oil and water emulsion (Emulsigen) or a polyphosphazene polymer (PCPP) did not significantly enhance tgD-specific antibody titres or disease protection when compared with BGI/ARCs alone. Surprisingly, co-delivering a single dose of BGI/ARCs with tgD protein in PBS had optimal adjuvant activity and the dose of IFN-gamma delivered was four-fold less than the dose previously shown to induce adverse systemic responses.

A discrete-event computer model of feline herpes virus within cat populations.

The purpose of this work was to study the epidemiology of feline herpes virus (FHV), which causes a respiratory disease within natural populations of domestic cats. A stochastic model was constructed using discrete-events simulation. Two habitats (rural vs. urban) were simulated, featuring different demographic, spatial and social patterns. The evolution of immunity in individuals was reproduced, allowing for the random recrudescence of latent infections (influenced by environment and reproduction). Hypotheses concerning the circulation of FHV were examined regarding the role of host density and the possibility of reinfection of host. Uncertainty analyses were performed on the basis of replicated Monte Carlo sampling. The results were in good agreement with serologic data from a long-term study conducted on five populations in France. The model satisfactorily reproduced the variability of natural immunity, and the epidemic features observed. The simulations have shown that FHV can persist in small populations (because of its capacity of reactivation leading to epidemics). However, the impact on demography was not dramatic. The most important parameters in determining change in epidemiology of FHV were: transmission rate corresponding to 'friendly' contacts, and the recrudescence rate of FHV. However, an interaction between these two parameters did not allow estimation of their values.