In the Superspreading Events database, we try to establish how many people were infected at the event itself , because this helps us to guage the risks involved in that situation.  However, press reports often refer to the total number of cases linked to  a superspreading event.  Linked cases include those in the wider community arising from the superspreading event.  For example, if 20 people were infected at a party, and some of those people infected 30 household members, an epidemiological investigation would conclude that 50 cases were linked to the party.  But in terms of assessing the risks of a setting, there are important differences.   Index and Secondary Cases An  index case  at an event is a person who brings the infection there.  There may be more than one.  Index cases are also known as 'Primary cases'. Secondary cases  are people who became infected in this setting. Tertiary cases  are people who later...