Tochukwu Raphael Abadom1, Adrian D Smith2, Stefano Tempia3, Shabir A Madhi4, Cheryl Cohen5, Adam L Cohen6. 1. Nuffield Department of Population Health, University of Oxford, Oxford, England. Electronic address: abadomtochukwu@gmail.com. 2. Nuffield Department of Population Health, University of Oxford, Oxford, England. Electronic address: adrian.smith@dph.ox.ac.uk. 3. Influenza Program, Centers for Disease Control and Prevention, Pretoria, South Africa; Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA. Electronic address: stefanot@nicd.ac.za. 4. Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa. Electronic address: ShabirM@nicd.ac.za. 5. Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa. Electronic address: cherylc@nicd.ac.za. 6. Influenza Program, Centers for Disease Control and Prevention, Pretoria, South Africa; Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA; U.S. Public Health Service, Rockville, MD, USA; Expanded Programme on Immunization, Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland(1). Electronic address: cohena@who.int.
Abstract
BACKGROUND: Influenza is a common cause of severe respiratory illness, but risk factors for hospitalisation in low income settings with a high HIV prevalence are not well described. We aimed to assess risk factors associated with influenza-associated severe acute respiratory illness (SARI) hospitalisation in South Africa. METHODS: We conducted a case-population study using data on risk conditions in patients hospitalised with SARI and the national prevalence of these conditions. Data on hospitalised cases were from the national SARI surveillance program while data on the referent population were from the latest national census or health and demographic surveillance surveys. FINDINGS: From 2009 to 2012, we identified 3646 (7.9%) of 46,031 enrolled cases of SARI that were associated with influenza infection. Risk factors associated with hospitalisation included previous history of smoking [case-population ratio (CPR) 3.82, 95% confidence interval (CI) 3.5-4.16], HIV infection (CPR 3.61, 95% CI 3.5-3.71), asthma (CPR 2.45, 95% CI 2.19-2.73), previous history of hospital admission in the past 12months (CPR 2.07, 95% CI 1.92-2.23), and tuberculosis (CPR 1.85, 95% CI 1.68-2.02). When stratified by age, there is increased risk of hospitalisation in those ⩽5yearsof age (CPR 3.07, 95% CI 2.93-3.21) and among those 35yearsof age and above (CPR 1.23, 95% CI 1.28-1.18). Male sex (CPR 0.85, 95% CI 0.82-0.88) and completion of pneumococcal conjugate vaccination schedule in children <5yearsof age (CPR 0.74, 95% CI 0.71-0.77) were associated with decreased risk of hospitalisation. CONCLUSION: These results identify groups at high-risk for severe influenza who should be considered potential targets for influenza vaccination in South Africa and similar settings.
BACKGROUND: Influenza is a common cause of severe respiratory illness, but risk factors for hospitalisation in low income settings with a high HIV prevalence are not well described. We aimed to assess risk factors associated with influenza-associated severe acute respiratory illness (SARI) hospitalisation in South Africa. METHODS: We conducted a case-population study using data on risk conditions in patients hospitalised with SARI and the national prevalence of these conditions. Data on hospitalised cases were from the national SARI surveillance program while data on the referent population were from the latest national census or health and demographic surveillance surveys. FINDINGS: From 2009 to 2012, we identified 3646 (7.9%) of 46,031 enrolled cases of SARI that were associated with influenza infection. Risk factors associated with hospitalisation included previous history of smoking [case-population ratio (CPR) 3.82, 95% confidence interval (CI) 3.5-4.16], HIV infection (CPR 3.61, 95% CI 3.5-3.71), asthma (CPR 2.45, 95% CI 2.19-2.73), previous history of hospital admission in the past 12months (CPR 2.07, 95% CI 1.92-2.23), and tuberculosis (CPR 1.85, 95% CI 1.68-2.02). When stratified by age, there is increased risk of hospitalisation in those ⩽5yearsof age (CPR 3.07, 95% CI 2.93-3.21) and among those 35yearsof age and above (CPR 1.23, 95% CI 1.28-1.18). Male sex (CPR 0.85, 95% CI 0.82-0.88) and completion of pneumococcal conjugate vaccination schedule in children <5yearsof age (CPR 0.74, 95% CI 0.71-0.77) were associated with decreased risk of hospitalisation. CONCLUSION: These results identify groups at high-risk for severe influenza who should be considered potential targets for influenza vaccination in South Africa and similar settings.
Authors: R A Adegbola; A G Falade; B E Sam; M Aidoo; I Baldeh; D Hazlett; H Whittle; B M Greenwood; E K Mulholland Journal: Pediatr Infect Dis J Date: 1994-11 Impact factor: 2.129
Authors: Denise J Jamieson; Margaret A Honein; Sonja A Rasmussen; Jennifer L Williams; David L Swerdlow; Matthew S Biggerstaff; Stephen Lindstrom; Janice K Louie; Cara M Christ; Susan R Bohm; Vincent P Fonseca; Kathleen A Ritger; Daniel J Kuhles; Paula Eggers; Hollianne Bruce; Heidi A Davidson; Emily Lutterloh; Meghan L Harris; Colleen Burke; Noelle Cocoros; Lyn Finelli; Kitty F MacFarlane; Bo Shu; Sonja J Olsen Journal: Lancet Date: 2009-07-28 Impact factor: 79.321
Authors: William W Thompson; David K Shay; Eric Weintraub; Lynnette Brammer; Carolyn B Bridges; Nancy J Cox; Keiji Fukuda Journal: JAMA Date: 2004-09-15 Impact factor: 56.272
Authors: Maurice O Ope; Mark A Katz; Barrack Aura; Stella Gikunju; M Kariuki Njenga; Zipporah Ng'ang'a; John Vulule; Robert F Breiman; Daniel R Feikin Journal: PLoS One Date: 2011-05-26 Impact factor: 3.240
Authors: Ji Yun Noh; Jacob Lee; Won Suk Choi; Joon Young Song; Yu Bin Seo; In Seon Kim; Hee Jin Cheong; Woo Joo Kim Journal: Emerg Infect Dis Date: 2013-01 Impact factor: 6.883
Authors: Tom H Boyles; Adrian Brink; Greg L Calligaro; Cheryl Cohen; Keertan Dheda; Gary Maartens; Guy A Richards; Richard van Zyl Smit; Clifford Smith; Sean Wasserman; Andrew C Whitelaw; Charles Feldman Journal: J Thorac Dis Date: 2017-06 Impact factor: 2.895
Authors: Antonia Ho; Stephen J Aston; Hannah Jary; Tamara Mitchell; Maaike Alaerts; Mavis Menyere; Jane Mallewa; Mulinda Nyirenda; Dean Everett; Robert S Heyderman; Neil French Journal: Clin Infect Dis Date: 2018-03-05 Impact factor: 9.079