Paine et al. recently reported an estimate of the reproduction number (R) for 2009 pandemic influenza A(H1N1) in New Zealand . Given that early epidemiological assessments of pandemic potential (i.e. transmission potential and severity of the disease) were limited in accuracy and precision, identifying technical pitfalls in relevant past studies is of the utmost importance. While we enjoyed reading Paine et al.'s contribution , we believe more emphasis on the estimation framework and relevant data needs is essential for improving future studies. Namely, constructing an epidemic model involving imported cases requires particular attention to the estimation of the number of secondary cases generated by a single imported case relative to the time since immigration (i.e. arrival of the imported case into the country).
Kelly, P. M., Mercer, G. N., Glass, K., & Paine, S. (2010). Author’s reply: Estimation of the reproduction number for 2009 pandemic influenza a(H1N1) in the presence of imported cases. Eurosurveillance. European Centre for Disease Prevention and Control (ECDC). https://doi.org/10.2807/ese.15.29.19623-en