Hippocrates - record of an in uenza pandemic in the year 412 b. c. Since 1580s, there ahve been 31 additional ue pandemics recorded. 50m deaths worldwide in less than 2 years. 500,000 death in the us (19,000 in nyc) 300,000 cases in ontario - 8700 death (1200 d in tor. just 3 wks) 500,000 cases and 14,000 deaths in quebec. Fever, chills, headache, weakness and fatigue as well as coughing, sneezing, runny nose (coryza) Residual cough and tiredness lasts up to 6 wks. Complications can include ear infections, pneumonia, dehydration and death. 3 types of in uenza virus: in uenza a (most virulent, b, & c. In uenza a and c infect multiple species, while b almost only infect humans. New and virulent u strains are produced mainly from the effects of 2 surface proteins. Hemagglutinin (h) - critical to virus entry into cell. Neuraminidase (n) - allows virus to leave host cell after.