Influenza A (H1N1), resumen de las características clínicas importantes (2)

Para complementar la revisión del 15 de junio (http://drvictorcastaneda.blogspot.com/2009/06/influenza-h1n1-resumen-de-las.html ) se publicó un nuevo artículo en la NEJM, éste hace un resumen de las características clínicas la influenza A H1N1, IMPORTANTEMENTE siguen siendo fiebre y tos los dos signos-síntomas CLAVE para la sospecha clínica ya que se presentan en el promedio en el 90% de los casos, lo que cambió radicalmente fueron los síntomas gastrointestinales como diarrea y fiebre, en éste estudio formaron parte de los hallazgos más frecuentes. Tanto la diarrea como los vómitos NO son característicos de una influenza estacional, lo que podría ser una ayuda diagnóstica MUY IMPORTATE. Pero la pregunta difícil de contestar sería como ahora los síntomas GI son más importantes que los hallazgos reportados por la OMS en el anterior artículo revisado ?

Resumen del estudio:

Entre 642 casos identificados en los EEUU, la edad media fué 20 años, 40% entre 10-18 años, 35% entre 19-50 años
94% fiebre
92% tos
66% diarrea
25% vómitos

9% fueron hospitalizados la edad varió de los 19 meses a 51 años, muchos de éstos con co-morbilidades crónicas asociadas

El virus era sensible para oseltamivir y zanamivir


Abstract original:

Characteristics of patients with H1N1 influenza

Clinical Question:
What are the typical presenting symptoms of patients with the novel H1N1 influenza initially detected in April 2009?

Bottom Line:
The initial outbreak of H1N1 influenza was characterized by symptoms similar to those seen in patients with seasonal influenza and by a low overall mortality. A very large number of patients with a mild form of the illness were likely not diagnosed. (LOE = 3b)

Reference:
Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team, Dawood FS, Jain S, et al. Emergence of a novel swine-origin influenza A (H1N1) virus in humans. N Engl J Med 2009;360(25):2605-2615. [PubMed Abstract]
Study Design: Cross-sectional
Funding: Government
Setting: Population-based

Synopsis:
Swine influenza viruses contain genes from human, swine, and avian influenza A viruses. A new variant of influenza A (H1N1) was initially detected in April, 2009, and has gone on to cause a worldwide pandemic. This report describes the characteristics of the first 642 cases identified in 41 states. The median age of patients was 20 years, with a range of 3 months to 81 years; 40% of patients were between the ages of 10 to 18 years, and 35% between 19 and 50 years. Patients presented with fever (94%), cough (92%), sore throat (66%), diarrhea (25%), and vomiting (25%); data were available regarding symptoms for 50% to 66% of patients, depending on the symptom. Hospitalization status was known for 399 patients, of whom 9% were hospitalized, with an age range of 19 months to 51 years. Many of the hospitalized patients had chronic medical conditions. The virus was sensitive to both oseltamivir and zanamivir. At the time of this writing (June 30, 2009) the CDC reported 27,717 confirmed or probable cases and 127 deaths (0.4%).