Caracterización de los recién nacidos con síndrome de down según condiciones de salud, demográficas y sociales en Medellín del periodo 2015 a 2019 / Characterization of newborns with Down Syndrome according to health, demographic and social conditions in Medellín from the period 2015 to 2019

Resumen La adaptación de una atención especializada para recién nacidos con Síndrome de Down (SD) requiere el reconocimiento de sus características a nivel local. Objetivo: caracterizar los recién nacidos diagnosticados con SD y sus madres en unidades de atención materno infantil de la ciudad de Medellín. Adicionalmente, se exploraron factores asociados al diagnóstico oportuno antenatal. Método: estudio observacional descriptivo de tipo transversal con intención analítica basado en registros médicos de recién nacidos diagnosticados con SD en siete instituciones de Medellín, Antioquia entre enero de 2015 y diciembre de 2019 teniendo en cuenta variables tanto maternas como neonatales. Se realizó un análisis univariado mediante frecuencias absolutas y relativas, luego se realizó un análisis bivariado teniendo en cuenta los desenlaces neonatales según el acceso al control prenatal y el momento en el cual se realizó el diagnóstico (prenatal o neonatal) y finalmente se realizó un análisis multivariado para diagnóstico neonatal tardío. Resultados: el 50,2% de las madres al momento del parto tenía 35 años o menos, de estas el 59,9% pertenecía al régimen contributivo y el 83,4% realizó 4 controles prenatales (CPN) o más, a pesar de esto, se encontró que sólo el 33,7% tenían diagnóstico prenatal de SD. La mayoría (91,4%) de los neonatos tuvo diagnóstico de cardiopatía congénita y la estancia hospitalaria prolongada estuvo en relación a morbilidad relacionadas. Conclusión: el SD es una de las cromosomopatías más común en nuestro medio, la cual se puede diagnósticar de forma temprana. Sin embargo en nuestro estudio se pudo evidenciar que pese a la alta cobertura de CPN la frecuencia del diagnóstico antenatal es menor, lo cual requiere que estos controles sean realizados por personal médico entrenado en pacientes con este tipo de patología. Esto finalmente se va a ver reflejado en una mejor aceptación por parte de la familia hacia la llegada de un hijo con esta condición y por supuesto, mejor acceso a servicios de salud especializados.

Abstract The adaptation of specialized care for newborns with Down syndrome (DS) requires recognition of its characteristics at the local level. Goal: to characterize newborns diagnosed with DS and their mothers in maternal and child care units in the city of Medellín. Also, explore the factors associated with timely prenatal diagnosis. Methods: observational, cross-sectional study, based on medical records of newborns diagnosed with DS in seven institutions in Medellín, Antioquia between January 2015 and December 2019, taking into account both maternal and neonatal variables. Initially, a univariate analysis was performed using absolute and relative frequencies, then a bivariate analysis was performed taking into account neonatal outcomes according to access to prenatal care and the time at which the diagnosis was made (prenatal or neonatal), and finally a multivariate analysis for late neonatal diagnosis. Results: 50.2% of the mothers at the time of delivery were 35 years old or younger, of these 59.9% belonged to the contributory regime and 83.4% had 4 prenatal check-ups or more, despite this, it was found that only 33.7% had a prenatal diagnosis of DS. The majority (91.4%) of the neonates had a diagnosis of congenital heart disease and the prolonged hospital stay was related to related morbidity. Conclusion: DS is one of the most common chromosomal abnormalities in our environment, which can be diagnosed early. However, in our study it was possible to show that despite the high coverage of prenatal controls, the frequency of antenatal diagnosis is lower, which requires that these controls be carried out by medical personnel trained in patients with this type of pathology. This will finally be reflected in a better acceptance by the family towards the arrival of a child with this condition and, of course, better access to specialized health services.

Differences in crop bacterial community structure between hoatzins from different geographical locations.

The hoatzin is the only known folivorous bird with foregut fermentation, and is distributed in Venezuela in rivers of the central savannas to the eastern Orinoco River. Differences in diet are expected to affect the digestive microbiota and we hypothesized that hoatzins from different habitats might have a different crop microbiota. We thus characterized the microbiota of six birds from the Cojedes and Orinoco Rivers using the G2 PhyloChip and, in parallel, we compared plant availability and foraging behavior of the hoatzins from the two locations. Plant composition differed between the 2 locations, which shared 5 out of 18 plant families and 1 plant genus--Coccoloba--that was highly consumed in both locations. The PhyloChip detected ∼1600 phylotypes from 42 phyla. There was a core microbiota with ~50% of the OTUs shared by at least 4 of the 6 individuals, but there were also differences in the crop microbiota of animals from the two regions. There existed a higher relative abundance of Alphaproteobacteria and Actinobacteria in the crops of birds from the Cojedes River and of Clostridia and Deltaproteobacteria in the crops of birds from the Orinoco River. The results showed both a core crop microbiota and also the bacterial taxa responsible for geographical differences among individuals from the two locations with different vegetation, suggesting an effect of both diet and geography in shaping the crop bacterial community of the hoatzin.

Comparative analyses of foregut and hindgut bacterial communities in hoatzins and cows.

Foregut fermentation occurs in mammalian ruminants and in one bird, the South American folivorous hoatzin. This bird has an enlarged crop with a function analogous to the rumen, where foregut microbes degrade the otherwise indigestible plant matter, providing energy to the host from foregut fermentation, in addition to the fermentation that occurs in their hindguts (cecum/colon). As foregut fermentation represents an evolutionary convergence between hoatzins and ruminants, our aim was to compare the community structure of foregut and hindgut bacterial communities in the cow and hoatzin to evaluate the influences of host phylogeny and organ function in shaping the gut microbiome. The approach used was to hybridize amplified bacterial ribosomal RNA genes onto a high-density microarray (PhyloChip). The results show that the microbial communities cluster primarily by functional environment (foreguts cluster separately from hindguts) and then by host. Bacterial community diversity was higher in the cow than in the hoatzin. Overall, compared with hindguts, foreguts have higher proportions of Bacteroidetes and Spirochaetes, and lower proportions of Firmicutes and Proteobacteria. The main host differences in gut bacterial composition include a higher representation of Spirochaetes, Synergistetes and Verrucomicrobia in the cow. Despite the significant differences in host phylogeny, body size, physiology and diet, the function seems to shape the microbial communities involved in fermentation. Regardless of the independent origin of foregut fermentation in birds and mammals, organ function has led to convergence of the microbial community structure in phylogenetically distant hosts.