Evaluación de la seroconversión de cerdas con el uso de un inóculo a diferentes dosis y vehículos contra la diarrea epidémica porcina

Porcine epidemic diarrhea (PED) is a highly contagious enteric disease of pigs, which has caused great economic losses to the swine industry worldwide. The known measure for PED control prior to the development and launch of vaccines in 2017 in Mexico, was "feedback" or "liquefaction". It was a widely used measure during the PED outbreak in 2013; however, there is no homogeneity in its use among the various authors who recommend it. Currently, several studies have experimented with other types of prophylaxis, such as oral immunization with PED virus obtained from cell culture isolation, which allows quantification of the infectious virus and ensures that only the virus, and no other agent, is being used as inoculum. The objective of the present study was to compare the time of seroconversion in sows inoculated with the quantified virus with four different vehicles (milk, wheat, direct, and water) and different doses of vehicle (1 ml, 2 ml, and 3 ml) at different pregnancy stages and with a different number of farrowings. The study was conducted at CEIEPP, a full-cycle farm with 170 females. The present study showed that the vehicles with the best results were the inoculum with water and the direct inoculum combined with the 1 ml dose, as the combination of these vehicles and an inoculum dose resulted in seroconversion in more than 90 % of the sows from the second week post inoculation.La diarrea epidémica porcina (PED) es una enfermedad entérica altamente contagiosa en los cerdos, que ha provocado grandes pérdidas económicas a la industria porcina a nivel mundial. Las medidas conocidas para el control de la PED, antes del desarrollo y lanzamiento de las vacunas en el 2017 en México, fue el “feedback” o “licuado”. Aunque fue una medida muy utilizada durante el brote de PED en 2013, entre los diversos autores que lo recomiendan no hay una homogeneidad en su uso. Actualmente, diversos estudios han experimentado otro tipo de profilaxis, como la inmunización oral con el virus de la PED obtenido a partir del aislamiento en cultivo celular, lo que permite cuantificar el virus infectivo, así como asegurar que solo se está utilizando como inóculo al virus y no otros agentes. El objetivo del presente estudio fue comparar el tiempo de seroconversión, en cerdas inoculadas con virus cuantificado, con cuatro diferentes vehículos (leche, trigo, directo y agua) y diferentes dosis del vehículo (1 ml, 2 ml y 3 ml), en diferentes momentos de gestación y número de partos. El estudio se realizó en el CEIEPP, granja de ciclo completo con 170 hembras. El presente estudio demostró que los vehículos con mejores resultados fueron el inóculo con agua y el inóculo directo combinado con la dosis de 1 ml, ya que la combinación de estos vehículos y dosis del inóculo generó que más del 90 % de las cerdas mostraran seroconversión a partir de la segunda semana post-inoculación

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Epidemiology, Molecular Epidemiology and Evolution of Bovine Respiratory Syncytial Virus

The bovine respiratory syncytial virus (BRSV) is an enveloped, negative sense, single-stranded RNA virus belonging to the pneumovirus genus within the family Paramyxoviridae. BRSV has been recognized as a major cause of respiratory disease in young calves since the early 1970s. The analysis of BRSV infection was originally hampered by its characteristic lability and poor growth in vitro. However, the advent of numerous immunological and molecular methods has facilitated the study of BRSV enormously. The knowledge gained from these studies has also provided the opportunity to develop safe, stable, attenuated virus vaccine candidates. Nonetheless, many aspects of the epidemiology, molecular epidemiology and evolution of the virus are still not fully understood. The natural course of infection is rather complex and further complicates diagnosis, treatment and the implementation of preventive measures aimed to control the disease. Therefore, understanding the mechanisms by which BRSV is able to establish infection is needed to prevent viral and disease spread. This review discusses important information regarding the epidemiology and molecular epidemiology of BRSV worldwide, and it highlights the importance of viral evolution in virus transmission

Frecuencia de M. hyopneumoniae, M. hyorhinis y M. hyosynoviae en muestras nasales y de pulmón de cerdos con síntomas de neumonía enzoótica porcina

M. hyopneumoniae, M. hyorhinis and M. hyosynoviae are genetically related species of the genus Mycoplasma that affect pig production. The objective of this work was the isolation and identification by PCR of M. hyopneumoniae, M. hyorhinis and M. hyosynoviae from nasal swabs and lung samples of pigs from different regions of Mexico in order to determine the frequency of these species and to evaluate PCR as a diagnostic tool for PEP. Pigs aged 4 to 8 weeks with clinical diagnosis of PEP were included. Lung samples and nasal swabs were obtained for the isolation of the Mycoplasma in liquid Friis medium and identified by species-specific PCR based on the 16S rRNA subunit. Isolation was achieved in 37.11 % (36/97) of the samples. The three Mycoplasma species were identified in lung and nasal swab samples. Mycoplasma co-infection was identified in 27.77 % (10/36). The bacterial genera associated with Mycoplasma infections were E. coli, Bordetella, Enterobacter, SCN, Corynebacterium, Pasteurella, Streptococcus, Shigella and Klebsiella. Mixed infection was present in 26 nasal swabs (45.61 %) and absent in the lungs. It was concluded that the frequency of  Mycoplasma on  production  farms  was higher  than  expected (40.27 %). It was also identified other Mycoplasma species involved in the development of PEP. Therefore, surveillance through isolation and molecular techniques can be of great help to breeding stock providers, as well as for removing Mycoplasma from pig farms.M. hyopneumoniae, M. hyorhinis y M. hyopsynoviae son especies genéticamente relacionadas del género Mycoplasma que afectan la producción porcina. El objetivo de este trabajo fue el aislamiento e identificación por PCR de M. hyopneumoniae, M. hyorhinis y M. hyosynoviae a partir de hisopos nasales y muestras de pulmón de cerdos de diferentes regiones mexicanas para determinar la frecuencia de estas especies y evaluar la PCR como herramienta diagnóstica para NEP. Se incluyeron cerdos de 4 a 8 semanas con diagnóstico clínico de NEP. Se obtuvieron muestras de pulmón e hisopos nasales para el aislamiento de Mycoplasma en medio Friis líquido y se identificaron mediante la PCR especie-específica basada en la subunidad 16S rRNA. El aislamiento se logró en 37.11 % (36/97) muestras. Las tres especies de Mycoplasma se identificaron en muestras de pulmón e hisopos nasales. La co-infección por Mycoplasma se identificó en el 27.77 % (10/36). Los géneros bacterianos asociados a las infecciones por Mycoplasma fueron E. coli, Bordetella, Enterobacter, SCN, Corynebacterium, Pasteurella, Streptococcus, Shigella y Kebsiella. La infección mixta estuvo presente en 26 hisopos nasales (45.61 %) y ausente en pulmones. Se concluyó que la frecuencia de Mycoplasma en las fincas de producción fue mayor a la esperada (40.27 %). También se identificaron otras especies de Mycoplasma involucradas en el desarrollo de la NEP. Por lo tanto, la vigilancia asistida por el aislamiento y las técnicas moleculares pueden ser de gran ayuda para la eliminación de Mycoplasma de las explotaciones porcinas y para los proveedores de pie de cría

Caracterización de proteínas de fase aguda asociadas con un brote de virus de diarrea epidémica porcina en lechones y cerdas lactantes en México

The objective of this study was to determine the relationships between four acute phase proteins (APP), and the pathological effects of porcine epidemic diarrhea virus (PEDV) in piglets and sows. Virus detection was done in laboratory (PCR method) with feces samples. Blood samples were obtained from lactating sows and piglets that survived the first day of life according to the presence or absence of characteristic enteric signs (ES) of the disease: vomiting and diarrhea. (I) Neonatal piglets without ES (n=7), (II) Neonatal piglets with ES (n=8), (III) Sows without ES (n=6), and (IV) Sows with ES (n=6). To determine the APP concentration in blood, serum amyloid A (SAA) and haptoglobin (HAP) were determined by a non-species-specific commercial ELISA assay. C-reactive protein (CRP) and PIGMAP serum levels were quantified by monoclonal antibody sandwich ELISA assay. Finally, no significant differences (P>0.05) were found in serum concentrations of different APP between piglets and sows with and without ES. Piglet survival is linked by the degree of dehydration during diarrhea; PEDV causes ES quickly and severely before of the induction of pro-inflammatory cytokines, but this pathological synthesis still remains unclear.El objetivo de este estudio fue determinar la relación entre cuatro diferentes proteínas de fases aguda (APP) y los efectos patológicos causados por el virus de la diarrea epidémica porcina (PEDV) en lechones y cerdas. El diagnóstico en laboratorio (prueba PCR) del PEDV fue determinado a partir de muestras de heces de animales enfermos; posteriormente, los cerdos fueron clasificados en relación a la presencia o ausencia de signos entéricos (ES) característicos de la enfermedad: vómitos y diarrea. Los grupos fueron: (I) Lechones sin ES (n = 7), (II) Lechones con ES (n = 8), (III) Cerdas sin ES (n = 6) y (IV) Cerdas con ES (n = 6). La cuantificación en sangre de las APP fue a partir de ensayo ELISA (no específico) para Amiloide sérico A (SAA) y haptoglobina (HAP); en cambio, la Proteína C reactiva (CRP) y PIGMAP fueron cuantificados mediante un ensayo ELISA (sándwich) de anticuerpos monoclonales. Finalmente, no se encontraron diferencias significativas (P>0.05) en las concentraciones de las diferentes APP entre lechones y cerdas con y sin ES. La supervivencia de los lechones está relacionada con el grado de deshidratación durante la diarrea; PEDV provoca signos entéricos severos antes de la inducción de citoquinas pro-inflamatorias, sin embargo esta inducción patológica sigue sin tener respuesta

Newcastle Disease Virus: Potential Therapeutic Application for Human and Canine Lymphoma

Research on oncolytic viruses has mostly been directed towards the treatment of solid tumors, which has yielded limited information regarding their activity in hematological cancer. It has also been directed towards the treatment of humans, yet veterinary medicine may also benefit. Several strains of the Newcastle disease virus (NDV) have been used as oncolytics in vitro and in a number of in vivo experiments. We studied the cytolytic effect of NDV-MLS, a low virulence attenuated lentogenic strain, on a human large B-cell lymphoma cell line (SU-DHL-4), as well as on primary canine-derived B-cell lymphoma cells, and compared them to healthy peripheral blood mononuclear cells (PBMC) from both humans and dogs. NDV-MLS reduced cell survival in both human (42% ± 5%) and dog (34% ± 12%) lymphoma cells as compared to untreated controls. No significant effect on PBMC was seen. Cell death involved apoptosis as documented by flow-cytometry. NDV-MLS infections of malignant lymphoma tumors in vivo in dogs were confirmed by electron microscopy. Early (24 h) biodistribution of intravenous injection of 1 × 1012 TCID50 (tissue culture infective dose) in a dog with T-cell lymphoma showed viral localization only in the kidney, the salivary gland, the lung and the stomach by immunohistochemistry and/or endpoint PCR. We conclude that NDV-MLS may be a promising agent for the treatment of lymphomas. Future research is needed to elucidate the optimal therapeutic regimen and establish appropriate biosafety measures

Implications of the Immune Polymorphisms of the Host and the Genetic Variability of SARS-CoV-2 in the Development of COVID-19

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for the current pandemic affecting almost all countries in the world. SARS-CoV-2 is the agent responsible for coronavirus disease 19 (COVID-19), which has claimed millions of lives around the world. In most patients, SARS-CoV-2 infection does not cause clinical signs. However, some infected people develop symptoms, which include loss of smell or taste, fever, dry cough, headache, severe pneumonia, as well as coagulation disorders. The aim of this work is to report genetic factors of SARS-CoV-2 and host-associated to severe COVID-19, placing special emphasis on the viral entry and molecules of the immune system involved with viral infection. Besides this, we analyze SARS-CoV-2 variants and their structural characteristics related to the binding to polymorphic angiotensin-converting enzyme type 2 (ACE2). Additionally, we also review other polymorphisms as well as some epigenetic factors involved in the immunopathogenesis of COVID-19. These factors and viral variability could explain the increment of infection rate and/or in the development of severe COVID-19