Table 1.

Description of data sources used in analysis.

Source	Fields of interest	Data level used in analysis	Counts	References
Notified case count (New Zealand surveillance database EpiSurv)	Date of onset, testing, and notification for confirmed and probable cases of campylobacteriosis	Aggregated by notification date and city of residence in Hawkes Bay	1345	Ministry of Health New Zealand [3]
General practice consultations (HealthStat)	Visits for gastrointestinal complaints	Individual with visit date, age, and sex, for entire Hawkes Bay District Health Board area only	772	Cumming J and Gribben B [21]
Consumer helpline (HealthLine) calls	Consumer calls concerning gastrointestinal complaints	Individual with call date, age, sex, and residential city in Hawkes Bay	1196	St George IM and Cullen MJ [22]
Google Trends	User queries with keywords for gastrointestinal complaints	Normalized counts aggregated by date, query keyword, and Google Trends normalized count for entire Hawkes Bay District Health Board area only	Not applicable	Google Trends [23]
Twitter microblogs (from Gnip Historical PowerTrack service)	Tweets with keywords for gastrointestinal complaints	Individual tweets geocoded to cities in Hawkes Bay	191	Gnip [24]
School absenteeism records (from individual schools)	Absence owing to illness or any valid reason	Aggregated by schools for the 5 schools providing data, areas represented: Havelock North, Napier, and Hastings	23,836	Ministry of Education, New Zealand [25]