1. The phrase ‘flu in the air’ in the understanding of the common masses refers to many people having contracted the flu and that others (who haven’t yet contracted the flu) could possibly contract the flu (i.e. IF Allah Taáala so decrees). This phrase would then merely mean that there is a prevalence of flu amongst the people. However, one’s Aqeedah/belief must remain correct; the reality of which is that illness is from Allah alone; hence Allah Ta’aala has decreed for so many people to contract the flu at a given time. In short, as long as the latter meaning is taken and not that some other phenomena is directly responsible for the flu, it would be fine to use this expression and it will not affect one’s Aqeedah and tenets of faith.