Twitter Flu Map 2013 (image) Johns Hopkins University Caption This map indicates the prevalence of flu in the United States in the first week of January this year, 2013, as measured by the volume of flu-related tweets. States with higher flu rates are colored in a darker red. This year, in contrast to last January, the nation is awash in flu cases. Credit Mark Dredze/JHU Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.