Table 5.

 General recommendations for influenza surveillance and burden of disease studies in Africa during the 2009 H1N1 pandemic

General recommendations
Study design	• Multiple studies in diverse sites will help to better understand geographic and temporal differences in virus activity across the continent. • Assess A various outcomes to understand different aspects of influenza‐associated disease. • The most cost‐effective and informative design methodologies (serologic surveys and sentinel surveillance) are discussed in further detail in Table 6.
Population	• Participant populations should include diverse groups; however persons at increased risk for severe influenza‐associated disease should be well‐represented. • Demographic and epidemiologic features of participants should be described in any research report. • Studies in health care settings (outpatient clinics and hospitals) can help to understand the proportion of severe illness associated with infection. • Ideally, surveillance populations will be well‐described with accurate denominator data for incidence calculations.
Specimen collection criteria	• Specimen collection criteria should be specified in publications to allow extrapolation of influenza test results to a larger population. Ideally, specimen collection criteria should be standardized. Consideration should be given to using explicitly defined influenza‐like illness in acute care settings 50 , and severe acute respiratory illness (SARI) in acute care settings 18 . • Specimen collection criteria should be explicitly described in reports.
Laboratory testing	• Sensitive and specific laboratory tests should be used to diagnose influenza virus infection according to international guidelines; such as hemagglutination inhibition serological assay and RT‐PCR 51 . • Results should clearly cite laboratory protocols used as well as thresholds for positive laboratory tests.
Outcomes measured	• Standard surveillance and study outcomes should be used. These include incidence of influenza virus infection (generally by serology on paired sera), or incidence of symptomatic influenza illness in community, outpatient, or hospital settings (generally by serology on paired sera or RT‐PCR on upper respiratory specimens). In the case of outbreaks of a novel influenza virus, cross‐sectional studies assessing evidence of past influenza virus infection can also be valuable. • Research and surveillance focus should be on the impact of influenza upon public health, and not merely collection of specimens for virologic surveillance.
Analysis	• Analysis methods and data used to calculate disease attack rates should be clearly defined and presented in all reports. • Subgroup analyses of persons at increased risk of influenza‐associated disease (age extremes or certain chronic diseases) should be performed when possible.
Additional analyses	• Collection of epidemiologic and clinical data to determine risk factors of disease among persons in community incidence studies or burden of severe illness studies. • Collection of cost of care data as part of influenza burden of illness studies