Estimation of the National Disease Burden of Influenza-Associated Severe Acute Respiratory Illness in Kenya and Guatemala: A Novel Methodology

James A. Fuller, Aimee Summers, Mark A. Katz, Kim A. Lindblade, Henry Njuguna, Wences Arvelo, Sammy Khagayi, Gideon Emukule, Nivaldo Linares-Perez, John McCracken, D. James Nokes, Mwanajuma Ngama, Sidi Kazungu, Joshua A. Mott, Sonja J. Olsen, Marc Alain Widdowson, Daniel R. Feikin

Research output: Contribution to journalArticle

Abstract

Background: Knowing the national disease burden of severe influenza in low-income countries can inform policy decisions around influenza treatment and prevention. We present a novel methodology using locally generated data for estimating this burden. Methods and Findings: This method begins with calculating the hospitalized severe acute respiratory illness (SARI) incidence for children <5 years old and persons ≥5 years old from population-based surveillance in one province. This base rate of SARI is then adjusted for each province based on the prevalence of risk factors and healthcare-seeking behavior. The percentage of SARI with influenza virus detected is determined from provincial-level sentinel surveillance and applied to the adjusted provincial rates of hospitalized SARI. Healthcare-seeking data from healthcare utilization surveys is used to estimate non-hospitalized influenza-associated SARI. Rates of hospitalized and non-hospitalized influenza-associated SARI are applied to census data to calculate the national number of cases. The method was field-tested in Kenya, and validated in Guatemala, using data from August 2009-July 2011. In Kenya (2009 population 38.6 million persons), the annual number of hospitalized influenza-associated SARI cases ranged from 17,129-27,659 for children <5 years old (2.9-4.7 per 1,000 persons) and 6,882-7,836 for persons ≥5 years old (0.21-0.24 per 1,000 persons), depending on year and base rate used. In Guatemala (2011 population 14.7 million persons), the annual number of hospitalized cases of influenza-associated pneumonia ranged from 1,065-2,259 (0.5-1.0 per 1,000 persons) among children <5 years old and 779-2,252 cases (0.1-0.2 per 1,000 persons) for persons ≥5 years old, depending on year and base rate used. In both countries, the number of non-hospitalized influenza-associated cases was several-fold higher than the hospitalized cases. Conclusions: Influenza virus was associated with a substantial amount of severe disease in Kenya and Guatemala. This method can be performed in most low and lower-middle income countries.

Original languageEnglish (US)
Article numbere56882
JournalPloS one
Volume8
Issue number2
DOIs
StatePublished - Feb 27 2013

    Fingerprint

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)
  • General

Cite this

Fuller, J. A., Summers, A., Katz, M. A., Lindblade, K. A., Njuguna, H., Arvelo, W., Khagayi, S., Emukule, G., Linares-Perez, N., McCracken, J., Nokes, D. J., Ngama, M., Kazungu, S., Mott, J. A., Olsen, S. J., Widdowson, M. A., & Feikin, D. R. (2013). Estimation of the National Disease Burden of Influenza-Associated Severe Acute Respiratory Illness in Kenya and Guatemala: A Novel Methodology. PloS one, 8(2), [e56882]. https://doi.org/10.1371/journal.pone.0056882