BACKGROUND: We documented the introduction of 2009 pandemic influenza A virus subtype H1N1 (A[H1N1]pdm09) into South Africa and describe its clinical presentation, epidemiology, and transmissibility. METHODS: We conducted a prospective descriptive study of the first 100 laboratory-confirmed cases of A(H1N1)pdm09 infections identified through active case finding and surveillance. Infected patients and the attending clinicians were interviewed, and close contacts were followed up to investigate household transmission. FINDINGS: The first case was confirmed on 14 June 2009, and by 15 July 2009, 100 cases were diagnosed. Forty-two percent of patients reported international travel within 7 days prior to onset of illness. Patients ranged in age from 4 to 70 years (median age, 21.5 years). Seventeen percent of household contacts developed influenza-like illness, and 10% of household contacts had laboratory-confirmed A(H1N1)pdm09 infection. We found a mean serial interval (± SD) of 2.3 ± 1.3 days (range, 1-5 days) between successive laboratory-confirmed cases in the transmission chain. CONCLUSIONS: A(H1N1)pdm09 established itself rapidly in South Africa. Transmissibility of the virus was comparable to observations from outside of Africa and to seasonal influenza virus strains.
BACKGROUND: We documented the introduction of 2009 pandemic influenza A virus subtype H1N1 (A[H1N1]pdm09) into South Africa and describe its clinical presentation, epidemiology, and transmissibility. METHODS: We conducted a prospective descriptive study of the first 100 laboratory-confirmed cases of A(H1N1)pdm09 infections identified through active case finding and surveillance. Infected patients and the attending clinicians were interviewed, and close contacts were followed up to investigate household transmission. FINDINGS: The first case was confirmed on 14 June 2009, and by 15 July 2009, 100 cases were diagnosed. Forty-two percent of patients reported international travel within 7 days prior to onset of illness. Patients ranged in age from 4 to 70 years (median age, 21.5 years). Seventeen percent of household contacts developed influenza-like illness, and 10% of household contacts had laboratory-confirmed A(H1N1)pdm09 infection. We found a mean serial interval (± SD) of 2.3 ± 1.3 days (range, 1-5 days) between successive laboratory-confirmed cases in the transmission chain. CONCLUSIONS: A(H1N1)pdm09 established itself rapidly in South Africa. Transmissibility of the virus was comparable to observations from outside of Africa and to seasonal influenza virus strains.
Authors: Fatimah S Dawood; Seema Jain; Lyn Finelli; Michael W Shaw; Stephen Lindstrom; Rebecca J Garten; Larisa V Gubareva; Xiyan Xu; Carolyn B Bridges; Timothy M Uyeki Journal: N Engl J Med Date: 2009-05-07 Impact factor: 91.245
Authors: Christophe Fraser; Christl A Donnelly; Simon Cauchemez; William P Hanage; Maria D Van Kerkhove; T Déirdre Hollingsworth; Jamie Griffin; Rebecca F Baggaley; Helen E Jenkins; Emily J Lyons; Thibaut Jombart; Wes R Hinsley; Nicholas C Grassly; Francois Balloux; Azra C Ghani; Neil M Ferguson; Andrew Rambaut; Oliver G Pybus; Hugo Lopez-Gatell; Celia M Alpuche-Aranda; Ietza Bojorquez Chapela; Ethel Palacios Zavala; Dulce Ma Espejo Guevara; Francesco Checchi; Erika Garcia; Stephane Hugonnet; Cathy Roth Journal: Science Date: 2009-05-11 Impact factor: 47.728
Authors: A K N'gattia; D Coulibaly; N Talla Nzussouo; H A Kadjo; D Chérif; Y Traoré; B K Kouakou; P D Kouassi; K D Ekra; N S Dagnan; T Williams; I Tiembré Journal: BMC Public Health Date: 2016-09-13 Impact factor: 3.295