Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Mar 18;10(3):e0118884.
doi: 10.1371/journal.pone.0118884. eCollection 2015.

Mortality amongst patients with influenza-associated severe acute respiratory illness, South Africa, 2009-2013

Cheryl Cohen  1 , Jocelyn Moyes  1 , Stefano Tempia  2 , Michelle Groome  3 , Sibongile Walaza  4 , Marthi Pretorius  5 , Halima Dawood  6 , Meera Chhagan  7 , Summaya Haffejee  8 , Ebrahim Variava  9 , Kathleen Kahn  10 , Anne von Gottberg  11 , Nicole Wolter  11 , Adam L Cohen  2 , Babatyi Malope-Kgokong  4 , Marietjie Venter  12 , Shabir A Madhi  13
Affiliations

Mortality amongst patients with influenza-associated severe acute respiratory illness, South Africa, 2009-2013

Cheryl Cohen et al. PLoS One. .

Abstract

Introduction: Data on the burden and risk groups for influenza-associated mortality from Africa are limited. We aimed to estimate the incidence and risk-factors for in-hospital influenza-associated severe acute respiratory illness (SARI) deaths.

Methods: Hospitalised patients with SARI were enrolled prospectively in four provinces of South Africa from 2009-2013. Using polymerase chain reaction, respiratory samples were tested for ten respiratory viruses and blood for pneumococcal DNA. The incidence of influenza-associated SARI deaths was estimated at one urban hospital with a defined catchment population.

Results: We enrolled 1376 patients with influenza-associated SARI and 3% (41 of 1358 with available outcome data) died. In patients with available HIV-status, the case-fatality proportion (CFP) was higher in HIV-infected (5%, 22/419) than HIV-uninfected individuals (2%, 13/620; p = 0.006). CFPs varied by age group, and generally increased with increasing age amongst individuals >5 years (p<0.001). On multivariable analysis, factors associated with death were age-group 45-64 years (odds ratio (OR) 4.0, 95% confidence interval (CI) 1.01-16.3) and ≥65 years (OR 6.5, 95%CI 1.2-34.3) compared to 1-4 year age-group who had the lowest CFP, HIV-infection (OR 2.9, 95%CI 1.1-7.8), underlying medical conditions other than HIV (OR 2.9, 95%CI 1.2-7.3) and pneumococcal co-infection (OR 4.1, 95%CI 1.5-11.2). The estimated incidence of influenza-associated SARI deaths per 100,000 population was highest in children <1 year (20.1, 95%CI 12.1-31.3) and adults aged 45-64 years (10.4, 95%CI 8.4-12.9). Adjusting for age, the rate of death was 20-fold (95%CI 15.0-27.8) higher in HIV-infected individuals than HIV-uninfected individuals.

Conclusion: Influenza causes substantial mortality in urban South Africa, particularly in infants aged <1 year and HIV-infected individuals. More widespread access to antiretroviral treatment and influenza vaccination may reduce this burden.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: HD has received honoraria from Novartis and MSD and sponsored travel by Mylan. SAM has received honorarium from GSK, Pfizer, Novartis, Sanofi and MERCK. This does not alter the authors’ adherence to PLOS ONE policies on sharing data and materials. The other authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Flow chart of patients enrolled in the South African severe acute respiratory illness surveillance programme at four sites in South Africa, 2009–2013.
HIV—human immunodeficiency virus.
Fig 2
Fig 2. Number of patients testing influenza positive by subtype and influenza detection rate by epidemiologic week and year among patients hospitalized with severe acute respiratory illness at four sentinel surveillance sites, South Africa, 2009–2013.
Fig 3
Fig 3. Case-fatality proportions by age group and HIV status amongst patients hospitalized with influenza-associated SARI at four sentinel surveillance sites in South Africa, 2009–2013 (n = 1039).
See this image and copyright information in PMC

References

    1. McMorrow M, Wemankoy E, Tshilobo J, Emukule G, Mott J, et al. Severe acute respiratory illness deaths in Sub-Saharan Africa and the role of influenza: a case-series from 8 countries JInfectDis. 2015; In press. - PMC - PubMed
    1. Tempia S, Walaza S, Viboud C, Cohen AL, Madhi SA, Venter M, et al. Mortality Associated With Seasonal and Pandemic Influenza and Respiratory Syncytial Virus Among Children <5 Years of Age in a High HIV Prevalence Setting—South Africa, 1998–2009. ClinInfectDis. 2014; 58: 1241–1249. - PMC - PubMed
    1. Cohen C, Simonsen L, Sample J, Kang JW, Miller M, Madhi SA, et al. Influenza-related mortality among adults aged 25–54 years with AIDS in South Africa and the United States of America. ClinInfectDis. 2012; 55: 996–1003. - PMC - PubMed
    1. Cohen C, Simonsen L, Kang JW, Miller M, McAnerney J, Blumberg L, et al. Elevated influenza-related excess mortality in South African elderly individuals, 1998–2005. ClinInfectDis. 2010; 51: 1362–1369. 10.1086/657314 - DOI - PMC - PubMed
    1. Tempia S, Walaza S, Viboud C, Cohen AL, Madhi SA, Venter M, et al. Mortality Associated with Seasonal and Pandemic Influenza and Respiratory Syncytial Virus among Individuals Aged ≥5 Years in a High HIV-Prevalence Setting—South Africa, 1998–2009 EmergInfectDis. 2015; In press. - PMC - PubMed

Publication types

MeSH terms