Datos recientes de la epidemia de Influenza A H1N1

Pandemic Potential of a Strain of Influenza A (H1N1): Early Findings

El día de hoy tuve la oportunidad de ver el programa de Carmen Aristegui en CNN y esta excelente profesional entrevistó a dos miembros del equipo de investigación sobre esta novel epidemia, por lo que me permití buscar en internet el estudio aludido, el cual quiero compartir con ustedes, por que me ha parecido sumamente interesante. Los pongo el resúmen, pero puede acceder al texto completo con unas exclentes diapositivas en la siguiente dirección Sciencexpress

Christophe Fraser1* Christl A. Donnelly,1* Simon Cauchemez,1
William P. Hanage,1 Maria D. Van Kerkhove,1 T. Déirdre Hollingsworth,1
Jamie Griffin,1 Rebecca F. Baggaley,1 Helen E. Jenkins,1 Emily J. Lyons,1 Thibaut Jombart,1 Wes R. Hinsley,1Nicholas C. Grassly,1 Francois Balloux,1 Azra C. Ghani,1 Neil M. Ferguson1†; Andrew Rambaut,2 Oliver G. Pybus3; Hugo Lopez-Gatell,4 Celia M Apluche-Aranda,5 Ietza Bojorquez Chapela,4 Ethel Palacios Zavala4; Dulce Ma. Espejo Guevara6; Francesco Checchi,7 Erika Garcia,7 Stephane Hugonnet,7 Cathy Roth7

The WHO Rapid Pandemic Assessment Collaboration‡ 1MRC Centre for Outbreak Analysis & Modelling, Department of Infectious Disease Epidemiology, Imperial College London, Faculty of Medicine, Norfolk Place, London W2 1PG, UK. 2Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories Edinburgh EH9 3JT, UK. 3Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK. 4Directorate General of Epidemiology, FCO. De P. Miranda 177 5th Floor, Mexico City, 01480, Mexico. 5National Institute of Epidemiological Diagnosis and Reference, Prolongación Carpio No. 470 (3° piso), Col Santo Tomás, México City, C.P. 11340, Mexico. 6Secretaría de Salud - Servicios de Salud de Veracruz Soconusco No. 36 Colonia Aguacatal C.P. 910 Xalapa, Veracruz, México State. 7World Health Organization, 20 Av. Appia, 1211 Geneva, Switzerland.
*These authors contributed equally to this work.
†To whom correspondence should be addressed. E-mail: neil.ferguson@imperial.ac.uk
‡All authors are members of this collaboration.

A novel influenza A (H1N1) virus has spread rapidly across the globe. Judging its pandemic potential is difficult with limited data, but nevertheless essential to inform appropriate health responses. By analyzing the outbreak in Mexico, early data on international spread, and viral genetic diversity, we make an early assessment of transmissibility and severity. Our estimates suggest that 23,000 (range 6,000-32,000) individuals had been infected in Mexico by late April, giving an estimated case fatality ratio (CFR) of 0.4% (range 0.3% to 1.5%) based on confirmed and suspect deaths reported to that time. In a community outbreak in the small community of La Gloria, Veracruz no deaths were attributed to infection, giving an upper 95% bound on CFR of 0.6%. Thus while substantial uncertainty remains, clinical severity appears less than that seen in 1918 but comparable with that seen in 1957. Clinical attack rates in children in La Gloria were twice that in adults (<15 years-of-age: 61%, ≥15: 29%). Three different epidemiological analyses gave R0 estimates in the range 1.4-1.6, while a genetic analysis gave a central estimate of 1.2. This range of values is, consistent with 14 to 73 generations of human-to-human transmission having occurred in Mexico to late April. Transmissibility is therefore substantially higher than seasonal flu, and comparable with lower estimates of R0 obtained from previous influenza pandemics.