1. MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, Faculty of Medicine, Norfolk Place, London W2 1PG, UK.
2. Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, Edinburgh EH9 3JT, UK.
3. Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
4. Directorate General of Epidemiology, FCO. De P. Miranda, 177 5th Floor, Mexico City, 01480, Mexico.
5. National Institute of Epidemiological Diagnosis and Reference, Prolongación Carpio No. 470 (3° piso), Col Santo Tomás, México City, C.P. 11340, Mexico.
6. Secretaría de Salud - Servicios de Salud de Veracruz Soconusco No. 36, Colonia Aguacatal, C.P. 910 Xalapa, Veracruz, México State.
7. World Health Organization.