Figure 1. Percentage of pigs that tested positive for IAV by real-time reverse transcription PCR at 6 IAV-positive agricultural fairs, Ohio and Indiana, USA, 2014 and 2015. Each data point represents the prevalence at that sampling timepoint connected with colored lines to indicate trend over time for each individual fair. IAV prevalence rises steeply through the latter half of each fair, indicating the strong role of lengthy show duration in increased viral amplification in each swine population. The reference line shows the recommended 72-hour cutoff for swine show duration. IAV, influenza A virus.