Introduction. Surveillance for laboratory-confirmed influenza-associated deaths in children is used to monitor the severity of influenza at the population level and to inform influenza prevention and control policies. The goal of this study was to better estimate pediatric influenza mortality in New York state (NYS). Methods. Death certificate data were requested for all passively reported deaths and any pneumonia and influenza (P&I) coded pediatric deaths occurring between October 2004 and April 2010, excluding New York City (NYC) residents. A matching algorithm and capture-recapture analysis were used to estimate the total number of influenza-associated deaths among NYS children. Results. Thirty-four laboratory-confirmed influenza-associated pediatric deaths were reported and 67 death certificates had a P&I coded death; 16 deaths matched. No laboratory-confirmed influenza-associated death had a pneumonia code and no pneumonia coded deaths had laboratory evidence of influenza infection in their medical record. The capture-recapture analysis estimated between 38 and 126 influenza-associated pediatric deaths occurred in NYS during the study period. Conclusion. Passive surveillance for influenza-associated deaths continues to be the gold standard methodology for characterizing influenza mortality in children. Review of death certificates can complement but not replace passive reporting, by providing better estimates and detecting any missed laboratory-confirmed deaths. 1. Introduction It has long been recognized that influenza is associated with substantial mortality during both epidemics and pandemics. Death due to influenza virus infection can result from a variety of causes, such as pneumonia or exacerbations of existing cardiopulmonary or other chronic conditions. Influenza-associated death among children in particular is rare, but when it occurs, it is often rapidly fatal and may affect children with no predisposing risk factor [1, 2]. Bacterial coinfections, especially methicillin-resistant Staphylococcus aureus (MRSA), are also increasingly being documented among influenza-associated pediatric deaths [1]. These were important factors in the Advisory Committee on Immunization Practices (ACIP) expanding influenza vaccine recommendations in 2008 to include all children aged 6 months through 18 years [3] when in years prior influenza vaccine was only recommended for children less than five years of age. Due to increased reports of deaths in children associated with influenza in the 2003-04 season [4, 5], in October 2004 laboratory-confirmed
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