title: Determining the Provincial and National Burden of Influenza-Associated Severe Acute Respiratory Illness in South Africa Using a Rapid Assessment Methodology.
abstract: Local disease burden data are necessary to set national influenza vaccination policy. In 2010 the population of South Africa was 50 million and the HIV prevalence was 11%. We used a previously developed methodology to determine severe influenza burden in South Africa. Hospitalized severe acute respiratory illness (SARI) incidence was calculated, stratified by HIV status, for four age groups using data from population-based surveillance in one site situated in Gauteng Province for 2009-2011. These rates were adjusted for each of the remaining 8 provinces based on their prevalence of risk factors for pneumonia and healthcare-seeking behavior. We estimated non-hospitalized influenza-associated SARI from healthcare utilization surveys at two sites and used the percent of SARI cases positive for influenza from sentinel surveillance to derive the influenza-associated SARI rate. We applied rates of hospitalized and non-hospitalized influenza-associated SARI to census data to calculate the national number of cases. The percent of SARI cases that tested positive for influenza ranged from 7-17% depending on age group, year, province and HIV status. In 2010, there were an estimated 21,555 total severe influenza cases in HIV-uninfected individuals and 13,876 in HIV-infected individuals. In 2011, there were an estimated 29,892 total severe influenza cases in HIV-uninfected individuals and 17,289 in HIV-infected individuals. The incidence of influenza-associated SARI was highest in children <5 years and was higher in HIV-infected than HIV-uninfected persons in all age groups. Influenza virus was associated with a substantial amount of severe disease, especially in young children and HIV-infected populations in South Africa.
authors.affiliation: Johns Hopkins International Vaccine Access Center, Baltimore, Maryland, United States of America.
authors.forename: Jillian
authors.initials: J
authors.lastname: Murray
authors.affiliation: Centers for Disease Control and Prevention, Pretoria, South Africa; Centers for Disease Control and Prevention, Atlanta, United States of America.
authors.forename: Adam
authors.initials: A
authors.lastname: Cohen
authors.affiliation: National Institute of Communicable Diseases, Johannesburg, South Africa.
authors.forename: Sibongile
authors.initials: S
authors.lastname: Walaza
authors.affiliation: Medical Research Council: Respiratory and, Meningeal Pathogens Research Unit, Johannesburg, South Africa.
authors.forename: Michelle
authors.initials: M
authors.lastname: Groome
authors.affiliation: National Institute of Communicable Diseases, Johannesburg, South Africa; Medical Research Council: Respiratory and, Meningeal Pathogens Research Unit, Johannesburg, South Africa; Schools of Public Health and Pathology, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Shabir
authors.initials: S
authors.lastname: Madhi
authors.affiliation: Klerksdorp Tshepong Hospital, Klerksdorp, South Africa.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Variava
authors.affiliation: Schools of Public Health and Pathology, University of the Witwatersrand, Johannesburg, South Africa; University of KwaZulu-Natal, Durban, South Africa; Umeå University, Umeå, Sweden; INDEPTH Network, Accra, Ghana.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Kahn
authors.affiliation: University of KwaZulu-Natal, Durban, South Africa; Pietermaritzburg Metropolitan Hospital Complex, Pietermaritzburg, South Africa.
authors.forename: Halima
authors.initials: H
authors.lastname: Dawood
authors.affiliation: Centers for Disease Control and Prevention, Pretoria, South Africa; National Institute of Communicable Diseases, Johannesburg, South Africa.
authors.forename: Stefano
authors.initials: S
authors.lastname: Tempia
authors.affiliation: National Institute of Communicable Diseases, Johannesburg, South Africa.
authors.forename: Akhona
authors.initials: A
authors.lastname: Tshangela
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, United States of America; National Institute of Communicable Diseases, Johannesburg, South Africa; Zoonoses Research Unit, Department of Medical Virology, University of Pretoria, Pretoria, South Africa.
authors.forename: Marietje
authors.initials: M
authors.lastname: Venter
authors.affiliation: Johns Hopkins International Vaccine Access Center, Baltimore, Maryland, United States of America; Centers for Disease Control and Prevention, Atlanta, United States of America.
authors.forename: Daniel
authors.initials: D
authors.lastname: Feikin
authors.affiliation: National Institute of Communicable Diseases, Johannesburg, South Africa; Schools of Public Health and Pathology, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Cohen
mesh_terms: D017281:Cost of Illness; D006679:HIV Seropositivity / Q000150:complications; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007251:Influenza, Human / Q000150:complications* / Q000453:epidemiology*; D008954:Models, Biological; D018571:Sentinel Surveillance; D045169:Severe Acute Respiratory Syndrome / Q000150:complications* / Q000453:epidemiology*; D013019:South Africa