Microfilaremic infection in canine filariosis in Colombia: a challenge in morphological and molecular diagnostics.

Canine filariosis is caused by filiform nematodes and affects several species of animals as well as humans. The disease produces a wide range of symptoms that can often be confused with other diseases, which increases the complexity of its diagnosis. The search for methodologies to facilitate its diagnosis is a challenge, and specific and differential identification of the parasite species causing the disease holds key to a successful diagnosis. In Colombia, there is a problem of underdiagnosis of filariosis in microfilaremic dogs infected by Dirofilaria immitis and Acanthocheilonema reconditum, and of microfilaremias not related to heartworm disease. The highest prevalences have been reported for D. immitis infections, although new cases of A. reconditum infections are beginning to appear. The aim of this study was to differentiate the microfilariae infections caused by D. immitis and A. reconditum by a morphological and molecular characterization of microfilariae so as to facilitate an accurate diagnosis of canine filariosis in the metropolitan area of Bucaramanga (Colombia). For this purpose, 400 blood samples with anticoagulants were collected from the dogs and analyzed with the help of a commercial immunochromatography kit for the detection of D. immitis circulating antigen. The Woo, Knott, and polymerase chain reaction (PCR) techniques were employed for determining the parasite count, morphological observation, and molecular identification of microfilariae present in the dogs respectively. The prevalence of microfilaremic dogs in Bucaramanga metropolitan area was 18.75% (75/400). The prevalence of dogs that tested positive for D. immitis in the antigen and in PCR tests was 1.25% (5/400) and 1% (4/400), respectively. Furthermore, the PCR test revealed that 17.75% of the microfilaremic dogs tested positive for A. reconditum (71/400) (first report in the metropolitan area of Bucaramanga), with one animal co-infected by both species, and 0% for D. repens (0/400). However, by morphological characterization, 4% of the microfilariae (3/75) corresponded to D. immitis, 20% (15/75) to D. repens, and 76% (57/75) to A. reconditum. The use of molecular diagnostic methods such as PCR aids in the specific identification of the parasite, thus making it a more accurate method than the morphological characterization of microfilariae. The identification of the parasites by PCR helps improve the veterinary diagnosis of canine filariosis in Colombia, which would lead to the establishment of an appropriate treatment protocol for each species of filaria and also to the generation of reliable data to be used at the clinical and epidemiological levels.

Current Situation of the Presence of Dirofilaria immitis in Dogs and Humans in Bucaramanga, Colombia.

The cardiopulmonary dirofilariosis caused by Dirofilaria immitis, is a vector-borne infection, which can be transmitted to humans. The main hosts are both domestic and wild canids. This species mainly occurs in tropical and subtropical climates, and temperature and humidity are the main factors that favor the presence and proliferation of culicid mosquitoes as vectors of the disease. There are few reports of cardiopulmonary dirofilariosis in dogs and humans in Colombia, a region with favorable climatic conditions which favors the presence of mosquitoes that act as vectors of the disease. Therefore, this study aimed to examine its current prevalence in dogs and the risk of human exposure to the disease in Bucaramanga, one of the most populated areas in Colombia located at the center of the country. Furthermore, its demographic and environmental characteristics could be useful as a study model for other similar locations and neighboring countries. Serum samples from 351 dogs and 506 humans from the Bucaramanga Metropolitan area were analyzed. All dog samples were analyzed by Knott's technique and tested with a commercial immunochromatographic to detect the presence of circulating antigens of D. immitis. Human samples were analyzed using a non-commercial ELISA test kit to detect IgG against the somatic antigens of adult D. immitis and Wolbachia. Positive results were further confirmed using western blot analysis. Thirty-eight dogs tested positive with a overall prevalence of 10.82%. Of these dogs, 18 showed D. immitis microfilariae, being 5.12% of the total population. The overall seroprevalence in humans was 6.71%; seroprevalence was significantly higher in individuals aged 16-34 years-old and in women than in men. To our knowledge, this study describes seropositivity to D. immitis for the first time in a Colombian human population located in the same area as that of dogs infected with D. immitis, which represents a potential threat to public health. In humans, age and gender can be considered risk factors for exposure to D. immitis.

Caracterización de decomisos de vísceras rojas en un frigorífico de exportación en Santander - Colombia / Characterising red viscera confiscation in an export slaughterhouse in Santander, Colombia / Caracterização de confiscos de vísceras vermelhas num frigorífico de exportação em Santander - Colômbia

Resumen A nivel mundial el decomiso de vísceras rojas es una de las principales causas de pérdidas económicas en la comercialización de productos cárnicos. El objetivo del presente estudio fue determinar las principales causas y variables epidemiológicas asociadas al decomiso de vísceras rojas en el FRIGORÍFICO RÍO FRÍO (FRF), del municipio de Floridablanca, Santander y estimar el valor de las pérdidas económicas asociadas a esta actividad. Entre 9 de noviembre al 9 de diciembre de 2018, se realizó un estudio transversal en el total de animales sacrificados en el FRF, a los cuales se les recolectó información epidemiológica posterior a la inspección sanitaria realizada por funcionarios del INVIMA. Las principales causas y variables epidemiológicas asociadas al decomiso de vísceras rojas se estimaron a partir de análisis de frecuencias, mientras el valor de las pérdidas económicas, a través de un análisis económico en el mercado nacional. Se sacrificaron un total de 8671 bovinos, y 226 búfalos, en los cuales se realizó el decomiso de vísceras rojas en el 15,8% y 26,5% de los animales, respectivamente. En los bovinos los principales órganos decomisados fueron pulmón, hígado y bazo con porcentajes del 87,4%, 11,1% y 0,6%, respectivamente. Mientras que, en los búfalos, fueron el pulmón, hígado y riñón con porcentajes del 88,3%, 8,3% y 1,7%, respectivamente. Las principales causas de decomiso de pulmón en ambas especies fueron la broncoaspiración (86,6%) y enfisema (9,4%), mientras para el hígado fueron los abscesos (40,5%) y la distomatosis hepática (28,8%) en los bovinos, hígado graso (80,0%) y cirrosis (20,0%) en los búfalos. Para el caso de los bovinos, hubo diferencias significativas en la proporción de animales con distomatosis hepática entre los diferentes municipios de Santander (χ² = 50.03, P < 0.05). Las mayores pérdidas económicas durante el periodo de estudio se deben al decomiso de pulmón e hígado con valores de 4886 y 2639 USD. En conclusión, el pulmón fue el órgano decomisado con mayor frecuencia en ambas especies, principalmente asociado a la broncoaspiración. Futuras estrategias de intervención, con el fin de reducir la broncoaspiración en los animales que ingresan a la planta de beneficio, e interrumpir el ciclo de vida de Fasciola hepatica en algunos municipios de Santander, son necesarios para disminuir el nivel de pérdidas económicas a lo largo de la cadena productiva.

Abstract Red viscera confiscation represents a significant cause of economic loss for the meat products' trade. This study was aimed at determining the causes and epidemiological variables associated with red viscera confiscation in a slaughterhouse (FRIGORÍFICO RÍO FRÍO (FRF)) located in Floridablanca, in Colombia's Santander department, and estimating the value of the economic losses associated with such confiscation. A cross-sectional study was carried out between November and December 2018 based on epidemiological information regarding all animals slaughtered at the FRF recorded after routine health inspection by Colombian Food and Drug Surveillance Institute (INVIMA) officials. Frequency analysis was used for estimating the main causes of and the epidemiological variables associated with red viscera confiscation whilst economic losses were estimated by national market analysis. It was found that red viscera were confiscated in 15.8% of 8,671 sacrificed cattle compared to 26.5% for 226 buffaloes. The lungs (87.4%), liver (11.1%) and spleen (0.6%) were the main organs seized for cattle and lungs (88.3%), liver (8.3%) and kidneys (1.7%) for buffaloes. Bronchoaspiration (86.6%) and emphysema (9.4%) were the main causes of confiscation regarding the lungs in both species while for the liver these were abscesses (40.5%) and hepatic dystomatosis (28.8%) in cattle and fatty liver (80.0%) and cirrhosis (20.0%) in buffaloes. There were significant differences regarding the percentage of cattle having hepatic dystomatosis amongst municipalities in the Santander department (χ²=50.03, p<0.05). Lung (4,886 USD) and liver confiscation (2,639 USD) led to the greatest economic losses; the lungs were the main organ confiscated in both species, mainly being associated with bronchoaspiration. Future intervention strategies are needed to reduce the livestock industry's financial losses, aimed at reducing bronchoaspiration in animals in the slaughterhouse and interrupting Fasciola hepatica's life-cycle in some municipalities in the Santander department.

Resumo Globalmente, os confiscos de órgãos e vísceras vermelhas é uma das principais causas de perdas econômicas na comercialização de produtos à base de carne. O objetivo deste estudo foi determinar as principais causas e variáveis epidemiológicas associadas aos confiscos de vísceras vermelhas num frigorífico (FRIGORÍFICO RÍO FRÍO (FRF)), do município de Floridablanca, Santander, e estimar o valor das perdas econômicas associadas a esta atividade. Entre 9 de novembro e 9 de dezembro do 2018, foi realizado um estudo transversal sobre o total de animais abatidos no FRF, nos quais a informação epidemiológica era diligenciada depois da inspeção sanitária realizada pelos funcionários do INVIMA. As principais causas e variáveis epidemiológicas associadas ao confisco de vísceras vermelhas foram estimadas a partir da análise de freqüência, e o valor de perdas econômicas, através de uma análise no mercado nacional. Foram abatidos 8.671 bovinos e 226 búfalos, nos quais 15,8% e 26,5% tiveram confiscos de vísceras vermelhas, respectivamente. Em bovinos, as principais vísceras confiscadas, foram pulmões, fígado e baço com percentagens de 87,4%, 11,1% e 0,6%, respectivamente. Nos búfalos, foram pulmões, fígado e rim com porcentagens de 88,3%, 8,3% e 1,7%, respectivamente. Para as duas espécies, broncoaspiração (86,6%) e enfisema (9,4%) foram as principais causas de confiscos dos pulmões. Para o fígado, foram os abcessos (40,5%) e fasciolose (28,8%) em bois, esteatose hepática (80,0%) e cirrose (20,0%) em búfalos. No caso dos bois, houve diferenças significativas na proporção de animais com fasciolose nos diferentes municípios do Santander (χ² = 50,03, P <0,05). As maiores perdas econômicas durante o período de estudo correspondem ao confisco de pulmão e fígado com valores de 4886 e 2639 USD. Em conclusão, o pulmão foi a principal víscera confiscada em ambas espécies, principalmente associados a broncoaspiração. Estratégias futuras de intervenção, com o objetivo de reduzir a broncoaspiração, e interromper o ciclo de vida da Fasciola hepatica em alguns municípios do Santander são necessários para reduzir as perdas econômicas na cadeia de produção.

Prevalence and molecular typing of rotavirus in children with acute diarrhoea in Northeastern Colombia.

After the introduction of the rotavirus vaccine, the number of rotavirus-associated deaths and the predicted annual rotavirus detection rate had slightly declined worldwide. Taking in account that in Colombia, Rotarix vaccine was introduced in 2009, the purpose of this study was to evaluate the presence of rotavirus A in children under five years who were treated for acute diarrhoea in Bucaramanga, Colombia and, moreover, to determine the genotypes of rotavirus present in those children. We performed an analytical cross-sectional study of rotavirus A in faecal samples from children up to five years of age. Stool samples were screened for rotavirus A using a lateral-flow immunochromatographic assay and confirmed using a VP6 sandwich ELISA. Genotyping of rotavirus A-positive samples was performed by PCR and sequencing of VP7 and VP4 genes. The overall prevalence of rotavirus was 30.53% (95% confidence interval [CI] 21.2 - 39.7). Most of the children with rotavirus (86.2%) had received two doses of the rotavirus vaccine. G3 strains accounted for the vast majority of cases (82.8%), followed by G12 strains (13.8%) and G3/G9 coinfections (3.4%). Among the P genotypes, P[8] was the most prevalent (69%), followed by P[9] (31%). The most common G[P] genotype combination was G3P[8], followed by G3P[9]. The main finding in this study was that rotavirus, in a Colombian region, is still an important pathogen in children under five years old, previously vaccinated. The results showed that different factors, such as kindergarten attendance, could explain the epidemiology and transmission of rotavirus in Bucaramanga.

Uso inercial de técnicas estadístico-inferenciales: su posible impacto en el hallazgo de resultados falsos en salud / Inertial use of statistical-inferential techniques: its possible impact on the finding of false health results

Objetivo:Sondear el grado en que importantes recursos estadísticos, en particular los valores p, los intervalos de confianza y los procedimientos para determinar tamaños muestral es, se emplean en la literatura biomédica de manera ritual. Metodología:se seleccionaron 25 artículos originales publicados en cada una de 4 revistas indexadas del campo biomédico. Para cada uno de ellos se evalúo si cumplían con las indicaciones de las guías STROBE y CONSORT en lo concerniente al tamaño de la muestra, así como el uso de los valores p, de los intervalos de confianza y la utilización de estos en la discusión del artículo. Resultados:el 97.0% de los artículos reporta el tamaño de la muestra, pero sólo el 62.9% explica cómo fue de-terminado. El valor p se usa con mayor frecuencia (68.0%) que los intervalos de confianza (63.9%). Solo el 15.5% usa los intervalos deconfianza en la discusión. Conclusión:las herramientas estadísticas más convencionales se emplean en buena medida de manera más ceremonial que funcional.

Objective: To evaluate the degree in which important statistical resources,particularly p-values, confidence intervals and procedures for determiningsample sizes, are used in the biomedical literature through a ritual way.Methodology:A total of 25 original articles published in each of 4journals indexed in the biomedical field were selected. For each of them,it was assessed whether they follow the instructions of the STROBE andCONSORT guidelines regarding the sample size, as well as the use of p-values, confidence intervals, and the use of these in the discussion of thearticle. Results:The 97.0% of the articles reported thesample size, but only 62.9% explained how it wasdetermined. The p-value is used more frequently(68.0%) than the confidence intervals (63.9%). Only15.5% uses confidence intervals in the discussionsection.Conclusion:the most conventional statistical toolsare used more in ceremonial way rather than in afunctional one.

Statistical tools in published articles of a public health journal in 2013 and 2014: bibliometric cross-sectional study.

INTRODUCTION: Research projects use statistical resources to express in numerical or graphic terms different magnitudes like frequencies, differences or associations. OBJECTIVES: The purpose of this paper is to describe the statistics tools utilization, with special emphasis in the use of conventional statistical tests and confidence intervals, to communicate results in a renowned public health peer reviewed journal in Colombia. METHODS: We included the 84 articles published in the journal between 2013 and 2014. RESULTS: The most used resource is frequency analysis (89.3%), followed by p values (65.5%) and confidence intervals (53.6%); 48.9% of the papers used confidence intervals together with p values; 29.8% use neither of them; 16.7% of the articles only used p values and 4.8% only confidence intervals. CONCLUSIONS: Descriptive statistics is a tool widely used in research results presentation; the critics and caveats suggesting to avoid the exclusive use of the statistical signification test in the results presentation are not followed in the analysis and presentation of the research results.

INTRODUCCIÓN : El desarrollo de proyectos de investigación suele demandar del uso de herramientas matemáticas para expresar en términos numéricos o gráficos diversas magnitudes, tales como frecuencias, diferencias, o asociaciones. OBJETIVOS: El presente estudio se propone describir la utilización que se hace de las herramientas estadísticas básicas, haciendo especial énfasis en el uso de las pruebas de significación estadística y los intervalos de confianza, para la presentación de resultados de investigación en los artículos publicados en una reconocida revista de la salud pública en Colombia. MÉTODOS: Se realizó una revisión de los 84 artículos originales publicados en dicha revista entre 2013 y 2014. RESULTADOS: El recurso más empleado es la utilización de análisis de frecuencias (89,3%), seguido de los valores p (65,5%) y los intervalos de confianza (53,6%); el 48,9% de los artículos utiliza a la vez intervalos de confianza y valores p para la presentación de resultados y el 29,8% ninguno de los dos. El 16,7% de los artículos sólo utiliza valores p y el 4,8% sólo intervalos de confianza. CONCLUSIONES: La estadística descriptiva es una herramienta que se utiliza con asiduidad en la presentación de resultados y que las críticas y advertencias sugiriendo que se evite el uso exclusivo de las pruebas de significación estadística en la presentación de resultados no son cabalmente tenidas en cuenta en el análisis y presentación de los resultados de investigación.