Rapid assessment of case recruitment tools to inform integrated surveillance of influenza and other respiratory viruses in Eastern Mediterranean countries.

Influenza-like illness (ILI) and severe acute respiratory infection (SARI) case recruitment tools from 10 countries were reviewed. The contents of the existing tools were compared against World Health Organization's current guidelines, and we also assessed the content validity (accuracy, completeness and consistency). Five of the ILI tools and two of the SARI tools were rated as having high accuracy against WHO case definitions. ILI completeness ranged from 25% to 86% and SARI from 52% to 96%. Average internal consistency scores were 86% for ILI and 94% for SARI. Limitations in the content validity of influenza case recruitment tools may compromise recruitment of eligible cases and result in varying detection rates across countries.