Lecture 10: 1918 influenza / hiv - aids. Hippocrates - record of an influenza pandemic in the year 412 b. c. Since 1580, there have been 31 additional flu pandemics recorded. Approximately 50 m deaths worldwide in less than 2 years: Spain did not censor how much it impacted the humans. 500,000 death in the us (19,000 in new york city) 300,000 cases in ontario - 8700 death (1200 deaths in toronto in just 3 weeks); 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 weeks. Complications can include ear infections, pneumonia, dehydration and death. Distinctive feature to flu= fever & extreme exhaustion/ fatigue; cold= rare. 3 types of influenza virus: influenza virus a (most virulent), b, &c (sporadic epidemic between children/young adults) Influenza a virus has 8 genes: genetically unstable, short incubation period 1-3 days, ease of transmission.