ABSTRACT
Despite that human parainfluenza type 3 viruses (HPIV3) are one of the leading causes of acute lower respiratory tract infections in children under five, there is no licensed vaccine and there is limited current information on the molecular characteristics of regional and global circulating strains. The aim of this study was to describe the molecular characterization of HPIV3 circulating in Buenos Aires. We performed a genetic and phylogenetic analysis of the HN glycoprotein gene. Between 2009 and 2013, 124 HPIV3-positive samples taken from hospitalized pediatric patients were analyzed. Four new genetic lineages were described. Among them, C1c and C3d lineages showed local circulation patterns, whereas C3e and C3f comprised sequences from very distant countries. Despite the diversity of the described genotypes, C3a and C3d predominated over the others, the latter was present during the first years of the study and it was progressively replaced by C3a. Molecular analyses showed 28 non-synonymous substitutions; of these, 13 were located in potentially predicted B-cell epitopes. Taken together, the emergence of genetic lineages and the information of the molecular characteristics of HN protein may contribute to the general knowledge of HPIV3 molecular epidemiology for future vaccine development and antiviral therapies.
Subject(s)
Genetic Variation , HN Protein/genetics , Parainfluenza Virus 3, Human/classification , Parainfluenza Virus 3, Human/genetics , Respirovirus Infections/virology , Argentina/epidemiology , Child , Child, Preschool , Evolution, Molecular , Female , Genotype , Humans , Infant , Infant, Newborn , Male , Parainfluenza Virus 3, Human/isolation & purification , Phylogeny , Phylogeography , Sequence Analysis, RNAABSTRACT
Disseminated encephalomyelitis (ADEM) is an infrequent condition with considerable morbidity and mortality in adult patients. It requires a high level of suspicion and diagnosis emerges by gathering clinical information, laboratory exams and images studies. ADEM is related to an immunological phenomena occurring after a bacterial/viral infection or recent vaccination. Glucocorticoids are the first line treatment, reserving immunoglobulins and plasmapheresis to refractory cases. We report a male patient aged 25, with ADEM associated to parainfluenza 3 virus respiratory infection that required mechanical ventilation and that had a complete recovery only after plasmapheresis.
La encefalomielitis aguda diseminada es una enfermedad infrecuente pero de elevada morbi-mortalidad en pacientes adultos. Demanda una sospecha y diagnóstico precoz que requiere el concurso de información clínica, pruebas de laboratorio y estudio de imágenes. De sustrato inmunológico, se puede relacionar a una infección viral, bacteriana o inmunización reciente. Los glucocorticoides son el tratamiento de elección, mientras que la inmunoglobulina intravenosa y la plasmaféresis se reservan para casos refractarios. Se presenta el caso de una encefalomielitis aguda diseminada grave, en un paciente de sexo masculino de 25 años, asociado a una infección respiratoria por virus parainfluenza 3. Requirió conexión a ventilación mecánica y tuvo una respuesta completa con plasmaféresis.