A Proof Of Concept For A Syndromic Surveillance System Based On Routine Ambulance Records In The South-west Of England, For The Influenza Season 2016/17

Thilo Reich; Marcin Budka

The human body temperature varies during the day due to changes in metabolism rates. The lowest oral measurement (37.2 • C) was found by Mackowiak et al. (1992) [16] to be at 6am and the highest (37.7 • C) at 4pm. A cohort study conducted by Obermeyer et al. (2017) [17] in 35,488 healthy patients confirmed the daily variation and found a normal range of 35.3-37.7 • C. This study also established a negligible discrepancy of -0.03 • C of tympanic versus oral temperature [17] . Therefore, temperatures between >37.7-42 • C, were considered as pyrexia where the upper cut-off accounts for hyperpyrexia [7] . The analysis was performed on records of patients with tympanic temperature readings within the range of 32-42 • C. This excluded 0.0306% of the records (i.e. moderate and severe hypothermia as well as hyperpyrexia) - Figure 1B [14].