Increased complaints of fever in the emergency room can identify influenza epidemics.

Abstract

BACKGROUND: In developing countries, it may be easier to use the reasons why patients come to the emergency room (ER) instead of sentinel practices to identify influenza epidemics. METHODS: We studied the reasons why adult patients present to the ER in order to attempt to predict increased hospital activity as a result of influenza. The daily frequency of presenting symptoms during the 30 days of maximal influenza activity was compared to the other days of the study period (335 days). RESULTS: During the influenza period, more patients presented with fever, syncope or near syncope, cough, asthma attack, and paralysis than on the days outside of this period. On 50% of the days, eight or more patients presented with fever, an 8.36 (95% CI=4.6-15.19) higher frequency than during the rest of the year. During the subsequent year, days with excess presentations by patients with a principal complaint of fever predicted increased hospital activity due to influenza with no false-positive periods. CONCLUSIONS: We conclude that an increase in the number of patients presenting to the ER complaining of fever can identify increased hospital influenza activity.