Global Tweets regarding a disease outbreak include concern from family or friends, local happenings and reiteration of news reports. Fig. 1 illustrates example Tweets and distribution of Twitter Updates in this study. The HL test yielded p-values of Â 1 and 0.185 (updates and mentions models). Large p-values indicate that the null hypothesis cannot be rejected and the model fits the expected distribution of values well, in this case, better for the updates model. Both models output a low probability (mentions: 0.04, updates: 6e-11) of an outbreak in Puerto Rico within 100 days, and there was no actual outbreak.